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Sebaceous carcinoma is a rare malignant skin neoplasm arising from sebaceous glands. Its clinical diagnosis is difficult and reports of dermoscopic findings have been limited. This study aims to analyze its dermoscopic features and differential diagnosis in dermoscopic examination. The study included patients diagnosed with histologically proven sebaceous carcinomas as well as diagnosed cases of sebaceous hyperplasia, sebaceoma, squamous cell carcinoma and basal cell carcinoma for comparison of dermoscopic findings. The dermoscopic criterion of presence of sebaceous carcinoma was scored only if the two evaluators reached a consensus. Fifteen cases of histologically diagnosed sebaceous carcinoma were included in our study. All cases were extraocular sebaceous carcinoma. A total of 60 (15 basal cell carcinomas, 15 squamous cell carcinomas, 15 sebaceous hyperplasias and 15 sebaceomas) cases were collected for comparing dermoscopic features with sebaceous carcinoma. In dermoscopic analysis of sebaceous carcinoma, the majority of tumors (66.67%) presented polymorphic vessel pattern. Other features included whitish-pink areas (80%), yellowish structures (73.33%) and yellowish structureless areas (60%). Yellowish structures in sebaceous carcinomas are the main dermoscopic findings to differentiate squamous cell and basal cell carcinomas (P < 0.001), whereas purplish globules, shiny white blotches and strands and whitish-pink area distinguish sebaceous carcinomas from other sebaceous tumors (P < 0.05).

An 11-year-old Doberman Pinscher with clinical and histological skin features consistent with colour dilution alopecia had a long history of skin disease. The animal had hundreds of papules affecting the ‘blue’ haired areas of the hair coat. The predominant skin lesions included keratinizing infundibular cysts, keratin horns, perifollicular dermatitis, and sebaceous hyperplasia; these lesions were often accompanied by furunculosis and suppurative panniculitis. Over a 9-month period, 32 lesions were examined histologically, which included two lipomas, one infiltrative lipoma, one squamous papilloma, two mast cell tumours, four cavernous haemangiomas, one haemangiosarcoma, and three melanomas. It is unknown at present whether the colour dilution phenotype confers increased risk for tumours of the skin and or subcutaneous tissues. Resume— Un doberman de 11 ans avec des manifestations cutanees cliniques et histologiques compatibles avec le diagnostic d'alopecie des couleurs diluees avait une longue histoire de problemes cutanes. L'animal presentait des centaines de papules affectant les zones de couleur bleue. Les lesions cutanees predominantes consistaient en kystes infundibulaires keratinisants, cornes cutanees, dermatite perifolliculaire et hyperplasie sebacee; ces lesions s'accompagnaient souvent de furonculose et de panniculite suppurative. Sur une periode de 9 mois, 32 lesions ont fait l'objet d'un examen histologique, dont deux lipomes, un lipome infiltrant, un papillome, deux mastocytomes, quatre hemangiomes caverneux, un hemangiosarcome, et trois melanomes. On ne sait actuellement pas si le phenotype couleur diluee constitue un facteur de risque accru pour les tumeurs de la peau et des tissus sous cutanes. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Tumeurs cutanees multiples chez un doberman presentant une alopecie des couleurs diluees.) Veterinary Dermatology 1997; 8: 59–62.] Resumen Un doberman pinscher de 11 anos con caracteristicas clinicas e histologicas compatibles con alopecia de color diluido tenia una larga historia de enfermedad cutanea. El animal presentaba centenares de papulas afectando las areas de pelo “azul”. Las lesiones predominantes incluian quistes infundibulares queratinizados, cuernos de queratina, dermatitis perifolicular e hiperplasia sebacea; estas lesiones se acompanaban de furunculosis y paniculitis supurativa. Durante un periodo de 9 meses, 32 lesiones fueron examinadas histologicamente, incluyendo 2 lipomas, un lipoma infiltrativo, un papiloma escamoso, dos mastocitomas, cuatro hemangiomas cavernosos, un hemangiosarcoma y tres melanomas. Se desconoce aun si el fenotipo de color diluido aumenta el riesgo para la aparicion de tumores en tejidos cutaneos y subcutaneos. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Multiples tumores cutaneos en un Doberman Pinscher con alopecia de color diluido.) Veterinary Dermatology 1997; 8: 59–62.] Zusammenfassung— Ein elfjahriger Dobermann mit klinischen und histologischen Befunden, die bei Farbmutantenalopezie auftreten, wies eine lange Vorgeschichte mit Hautkrankheiten auf. Das Tier zeigte Hunderte von Papeln, die die “blau” behaarten Bezirke des Felles betrafen. Die vorherrschenden Hautveranderungen bestanden in keratinisierenden infundibularen Zysten, Keratinhornern, perifollikularer Dermatitis und Talgdrusenhyperplasie; diese Veranderungen wurden oft von Furunkulose und eitriger Pannikulitis begleitet. Uber eine Zeitspanne von 9 Monaten wurden 32 Veranderungen histologisch untersucht, wovon zwei in Lipomen bestanden, eine in einem infiltrativen Lipom, eine in einem squamosen Papillom, zwei in Mastzelltumoren, vier in kavernosen Hamangiomen, eine in einem Hamangiosarkom und drei in Melanomen. Es ist zur Zeit nicht bekannt, ob der Phanotyp mit der Farbverdunnung mit einem erhohten Risiko fur Tumoren der Haut und/oder des subkutanen Gewebes einhergeht. [Madewell, B. R., Ihrke, P. J., Griffey, S. M. Multiple skin tumours in a Doberman Pinscher with colour dilution alopecia. (Multiple Hauttumoren bei einem Dobermann mit Farbmutantenalopezie.) Veterinary Dermatology 1997; 8: 59–62.]

GLUT1 is a membrane associated carrier protein that functions in the physiologic transport of glucose across cell membranes. Multiple studies have shown an increased GLUT1 expression in various tumor types and a role in cancer prognosis. The aim of this study was to determine whether cutaneous sebaceous lesions have a differential expression of GLUT1 by immunohistochemistry (IHC). GLUT1 IHC was performed on excision specimens of ten cases of sebaceous carcinoma, nine of sebaceoma, ten of sebaceous adenoma, and ten of sebaceous hyperplasia. Intense, diffuse cytoplasmic staining was observed in sebaceous carcinoma. The pattern of GLUT1 staining in sebaceomas and sebaceous adenomas consisted of a gradient of intense cytoplasmic staining in the basaloid cells with a decreased intensity to membranous staining only and absent staining in mature sebaceous cells. In lesions of sebaceous hyperplasia, GLUT1 staining outlined the basal layer of each gland, cytoplasmic staining was minimal to absent. Increased cytoplasmic staining of GLUT1 may correlate with cellular metabolic and proliferative activity. GLUT1 has potential utility in differentiating sebaceous lesions.

Tumors with sebaceous differentiation represent a challenge to diagnose, classify and occasionally to treat. The histopathologic spectrum of sebaceous neoplasia includes sebaceous adenoma, sebaceoma, and sebaceous carcinoma, while sebaceous hyperplasia represents hyperplasia of benign sebaceous glands surrounding a hair follicle. While often recognizable on morphologic grounds alone, sebaceous lineage also be informed by the application of immunohistochemical studies, including antibodies for adipophilin and Factor XIIIa (AC-1A1 clone). Sebaceous tumors are important to recognize given the relationship to the Muir-Tore autosomal dominant cancer predisposition syndrome. However, although it is well accepted that a sebaceous tumor might exhibit defects in mismatch repair, whether such a defect is related to germline defects in mismatch repair genes (or are due to somatically acquired alterations limited to the tumor cells) remains a critical clinical question with significant implications for the patient. Finally, recently published molecular studies have elaborated a molecular-genetic framework by which to understand the drivers of sebaceous carcinomas arising in different anatomic locations.

Aquaporin 3 (AQP3) is the membrane channel of water and involved in fluid homeostasis. The aim of this study was to reveal the expression and significance of AQP3 in cutaneous lesions. We analyzed AQP3 mRNA levels using RT-PCR in 311 cutaneous lesions and confirmed AQP3 expression in these lesions by immunohistochemistry. AQP3 mRNA was detected in normal epidermis, seborrheic keratosis, solar keratosis, Bowen’s disease, squamous cell carcinoma, eccrine poroma, apocrine carcinoma, and sebaceoma; however, AQP3 mRNA was absent in basal cell carcinoma, nevocellular nevus, or malignant melanoma. By immunohistochemistry, diffuse AQP3 expression was seen in all keratotic lesions including seborrheic keratosis, verruca vulgaris, molluscum contagiosum, solar keratosis, Bowen’s disease, and squamous cell carcinoma. Diffuse AQP3 expression was also present in all extramammary Paget’s disease. No AQP3 staining was obtained in basal cell carcinoma. Positive AQP3 staining was seen in sweat gland tumors including hidradenoma, eccrine poroma, and apocrine carcinoma. Among sebaceous tumors, AQP3 expressed diffusely in all sebaceous hyperplasia and sebaceous adenoma, but not in sebaceous carcinomas. Only focal AQP3 staining was seen in nevocellular nevus and no AQP3 staining in melanoma. Our findings indicate the function of AQP3 maintained in most skin tumors. AQP3 may be used for differential diagnosis in skin tumors.

Over a period of 1 year, a 74-year-old man slowly developed a painless left upper eyelid intratarsal mass. The skin was movable over the lesion. At surgery, a well-circumscribed, yellow-white, partially cystic tumor was encountered. Histopathologically it was composed of a random mixture of basaloid and sebaceous cells arranged in interconnecting cords. Immunohistochemical evaluation disclosed epithelial membrane antigen, adipophilin, and cytokeratin 14 positivity. These findings led to the diagnosis of a sebaceoma. The tumor cells abnormally failed to express mismatch repair proteins for MLH1 and PMS2. The patient did not have a personal history of any visceral malignancy, but his father had died at the age of 46 years and a daughter at the age of 33 years from colonic carcinomas. The implications of this periocular sebaceoma for the Muir-Torre syndrome are explored.

Introduction Reliable nuclear immunohistochemical stains for sebaceous neoplasms have not been readily available. Positive nuclear staining has been reported by GATA3 and factor XIIIa (AC-1A1). We sought to determine the diagnostic utility of these nuclear stains by comparing their staining pattern to adipophilin, a consistently positive cytoplasmic stain. Methods Cases with the diagnosis of sebaceous hyperplasia, sebaceous adenoma, sebaceous epithelioma/sebaceoma, and sebaceous carcinoma, nonsebaceous neoplasms (basal cell carcinoma, and squamous cell carcinoma) were examined. Intensity and extent of staining of the basal cells and mature sebocytes were evaluated for each stain. Results Factor XIIIa (AC-1A1) was 87.3% sensitive for all sebaceous neoplasms and 95.1% specific and demonstrated high inter-observer reliability. Adipophilin was 83.2% sensitive and 87.8% specific. GATA3 was the least sensitive (80.9%) and specific (75.6%) marker. When factor XIIIa was compared against composite staining of all three markers its staining was still uniquely significant (p = 0.0210). Conclusion Factor XIIIa (AC-1A1) is a sensitive and specific nuclear marker for sebaceous differentiation. Its diagnostic utility exceeds that of adipophilin. Factor XIIIa should be included in the expanding group of immunohistochemical and special stains which can be utilized to aid in the diagnosis of sebaceous neoplasms.

Introduction: Skin tumors are classified as melanocytic and non-melanocytic based on presence of melanocytes and melanin pigment in the tumor. Dermoscopy, being a non-invasive technique, is a proven method in recognizing the non-melanocytic and pink tumors by showing specific patterns. In Indian subcontinent, reports on dermoscopy of non-melanocytic and pink tumors are confined only to case reports. Authors studied dermoscopic features of non-melanocytic and pink skin tumors in dermoscopy. Materials and Methods: Study was carried in a tertiary hospital attached to S.Nijalingappa Medical College, Bagalkot, between January and December 2016. It was a descriptive study. Patients with signs of non-melanocytic and pink tumors were selected. Demographic data, such as age, gender, and clinical variables in terms of site of tumor and duration were documented. Manual DermLite 3 and videodermoscopy were employed. Both polarized and non-polarized versions were used for examination. Results: Totally 128 patients were present with 75 females and 61 males. Study included pyogenic granuloma (39), squamous cell carcinoma (4), basal cell carcinoma (30), keratoacanthoma (3), seborrheic keratosis (15), trichoepithelioma (2), syringoma (5), apocrine hydrocystoma (2), fibrokeratoma (5), dermatofibroma (6), epidermal cyst (7), sebaceous hyperplasia (2), Bowen's disease (1), steatocystoma multiplex (1), Lymphangioma circumscriptum (3) and milia (3). Numbers in parenthesis indicate number of patients. Conclusion: Dermoscopy of non-melanocytic and pink tumors demonstrates characteristic patterns which vary from white, yellow, brown to blue and red color depending on presence of keratin and hemoglobin. Patterns differ based on the type skin color. Recognition of distinctive vascular and keratin related pattern is of great help in the diagnosis of skin tumors. To the best our knowledge, this is first report of dermoscopy of non-melanocytic and pink tumors on a larger scale from Indian subcontinent.

The purpose of this study is to codify the microscopic diagnostic criteria for ocular adnexal brow and caruncular sebaceous gland hyperplasias (pseudoadenomatoid) that distinguish it from an adenoma. Clinical records and photographs were critically reviewed and microscopic slides were stained with hematoxylin and eosin and immunochemically stained for adipophilin, androgen receptor, p16, p53, a spectrum of cytokeratins, Ki-67 and mismatch repair nuclear protein expression for MLH1, MSH2, PMS2, and MSH6. The patients and their close relatives had no history of cancer. Cytokeratin 7 and especially cytokeratin 17 highlighted the presence of ducts in the hyperplastic lesion, which are not present in adenomas. p16 and p53 were negative and Ki-67 immunostaining demonstrated similar low proliferation indices for normal and hyperplastic glands. The mismatch repair nuclear protein expressions were preserved in both lesions. Histopathologic misdiagnosis of adenomatoid sebaceous gland hyperplasia as an adenoma can lead to the impression of an association with the Muir-Torre syndrome. Cytokeratins 7 and 17 immunostaining can be helpful in highlighting compressed ducts that in exuberant sebaceous gland hyperplasias may lead to a diagnosis of an adenoma (in which ducts are absent). Negative immunostaining for p16 rules out a possible etiologic role of human papillomavirus in hyperplasias and the negative p53 staining indicates the lesions are not truly neoplastic. The preservation of mismatch repair nuclear protein expression rules out the likelihood of the Muir-Torre syndrome. The current cases convincingly establish that sebaceous hyperplasia is not associated with the Muir-Torre syndrome by both clinical findings and immunohistochemical testing.Two yellow lesions, from the brow and caruncle, were examined microscopically and immunohistochemically to establish the diagnosis of sebaceous gland hyperplasia and to rule out the Muir-Torre syndrome.

Both architectural and cytologic characteristics are used to distinguish benign from malignant sebaceous neoplasms; however, specific cytopathologic features of sebocytes have not been well defined. The authors assessed architectural and cytological features of 63 sebaceous neoplasms [15 sebaceous hyperplasias, 12 sebaceomas, 16 sebaceous adenomas (SA), 14 sebaceous carcinomas (SC), and 6 ocular sebaceous carcinoma (OSC)] to investigate whether cytological grading may facilitate classification of lesions. Among other criteria, nuclear pleomorphism (size, nucleolar appearance, membrane irregularity, crowding, mitoses, and chromatin pattern) was assessed and 3 theoretical nuclear grades established. Immunohistochemistry for CK10, p16, adipophilin and ki67 was performed on 7 cases of each type of tumor. Most sebaceous neoplasms, except OSC, showed a bland architectural silhouette. However, SA, SC, and OSC revealed larger nuclei (≥14 μm in ≥50% of cases), evident to multiple nucleoli, membrane irregularity, coarse to clumped chromatin, and nuclear grade ≥2 (latter in ≥56% of cases); by contrast, sebaceous hyperplasia and sebaceomas showed smaller nuclei (≤10 μm in ≥50% of cases), smooth borders, inconspicuous nucleoli, fine chromatin, and grade 1 nuclei (latter in 100% of cases). In the setting of a well-circumscribed architecture, cytologic features gain importance in the classification of sebaceous neoplasms. Interestingly, cytologic similarities found in SA and SC may indicate a close relationship of both neoplasms.

Background Sebaceous carcinoma (SeC) is an uncommon malignancy arising from sebaceous glands of the conjunctiva and skin. Recurrent mutations in the ZNF750 were recently identified in ocular SeC. We assessed whether ZNF750 loss is a specific feature of ocular SeC or a general feature of sebaceous tumors. Methods Immunostaining for ZNF750 expression was performed in 54 benign and malignant sebocytic proliferations. Staining for ZNF750 was scored on a three-tier scale: positive (>75%), partially positive (5%-74%), and negative ( Results ZNF750 expression was negative in 4/11 ocular SeC, and partially positive in 4/11 ocular SeC and 6/13 cutaneous SeC. No extraocular tumors were negative. No loss was found in sebaceous adenoma or sebaceous hyperplasia. In nine previously sequenced ocular SeCs, two lacked detectable somatic mutations in ZNF750, but showed complete loss of staining, indicating non-mutational inactivation of ZNF750. Conclusion We show complete loss of the ZNF750 epidermal differentiation regulator in about half of ocular SeC, highlighting the most common genetic defect in this cancer type. Loss of ZNF750 expression is seen even in tumors without truncating mutations and reduced in many of the remaining ocular and cutaneous SeC. In contrast, no ZNF750 loss was detected in benign sebaceous proliferations.

Sebaceous adenoma is a benign epithelial neoplasm with hyperplasia of sebaceous lobules associated with expansive aggregates of basaloid germinative cells. Sebaceous adenomas usually demonstrate solitary or multiple lesions, particularly in the head and neck. Sebaceous adenomas can be associated with Muir-Torre syndrome which is a familial disorder with concomitant emergence of sebaceous neoplasm and a visceral malignancy or a concurrence of multiple keratoacanthomas and a visceral malignancy. Few to hundreds of gradually evolving, painless, yellow coloured papules or nodules with or without ulceration of the superficial epithelium are seen. Sebaceous adenomas commonly display distinct zones of clustered sebaceous lobules which are comprised of equivalent quantities of differentiated sebaceous cells and undifferentiated basaloid cells, accumulated within the papillary dermis. Mature sebaceous cells are immune reactive for Epithelial membrane antigen (EMA) and non-reactive for Carcino-embryonic antigen (CEA). Basaloid cells of sebaceous neoplasm are immune reactive for cytokeratin 7. Sebaceous adenoma requires distinction from sebaceous hyperplasia, sebaceous carcinoma, disorders with sebaceous differentiation, clear cell variations of eccrine, melanocytic, keratinocytic and xanthomatous conditions. Sebaceous adenoma is adequately managed by a comprehensive surgical excision with consequent minimal tumour reoccurrence.

Many cutaneous complications have been described in patients treated with cyclosporin. Alterations of the pilosebaceous unit such as hypertrichosis are particularly frequent. However, the occurrence of sebaceous hyperplasia is exceptional. These lesions seem to be specific to cyclosporin rather than secondary to immunosuppression. Here, we report an exceptional case of eruptive and disseminated sebaceous hyperplasia arising in a bone marrow transplant recipient only a few months after starting immunosuppressive treatment with cyclosporin.

Malic enzymes (MEs) are involved in fatty acid biosynthesis and lipid accumulation, and their expression in sebocytes and sebaceous lesions has not been investigated. The aims of this study were to examine ME1 and ME2 expression in normal skin and sebaceous lesions. A total of 68 cases including 5 specimens of normal skin, 12 facial lesions showing sebaceous hyperplasia, 18 sebaceous adenomas, 10 sebaceomas, 13 steatocystomas, and 10 sebaceous carcinomas were examined for the expression of ME1 and ME2. All benign and malignant sebaceous lesions showed ME1 in clear cells and ME2 in nonclear cells, respectively. ME1/ME2 phenotype is seen in basal sebocytes, basal keratinocytes, sweat glands, and outer root sheath cells and hence not specific. This study demonstrates that ME1/ME2 expression phenotype may have a potential to be a valuable marker for sebaceous differentiation. It is necessary to perform large-scale studies including skin tumors with a clear cell morphology that may mimic sebaceous differentiation.

Background Sebaceous proliferations are common and may be confused with other cutaneous neoplasms. Few useful or specific immunohistochemical markers for sebaceous differentiation are available. We incidentally observed strong factor XIIIa (Ventana clone AC-1A1 on Ventana Benchmark Ultra stainer) nuclear staining in normal sebaceous glands and hypothesized that this might be a useful marker in sebaceous proliferations. Methods Immunohistochemistry for factor XIIIa (AC-1A1) was performed on seven sebaceous hyperplasias, eight sebaceous adenomas, five sebaceomas, seven sebaceous carcinomas. Results Strong nuclear factor XIIIa (AC-1A1) staining was present in 100% of normal sebaceous glands, 100% of sebaceous hyperplasia, adenoma and carcinoma, and 80% of sebaceoma. Moderately or poorly differentiated squamous cell carcinomas (SCCs) (n = 26) were also stained for factor XIIIa (AC-1A1); two showed focal strong staining (8%), but the remainder showed only weak or negative staining (92%). In contrast, factor XIIIa clones from Abcam, Cambridge, MA, USA (EP3372) and Vector Laboratories, Burlingame, CA, USA (E980.1) were negative in sebocyte nuclei. Conclusions We report the novel finding of consistent nuclear factor XIIIa (AC-1A1) staining in normal, hyperplastic and neoplastic sebocytes. Factor XIIIa (AC-1A1) is a highly sensitive marker of sebaceous differentiation. It may have potential clinical utility as a specific marker to distinguish sebaceous carcinoma from poorly differentiated SCC.

Sebaceous carcinoma is a rare but serious malignancy that may be difficult to diagnose when poorly differentiated. Other epithelial tumors with clear cell change may mimic sebaceous carcinoma. Few useful or specific immunohistochemical markers for sebaceous differentiation are available. Nuclear staining with factor XIIIa (clone AC-1A1) was recently found to be a highly sensitive marker of sebaceous differentiation. We evaluated nuclear factor XIIIa (AC-1A1) staining in sebaceous neoplasms vs. other cutaneous clear cell tumors. We stained 27 sebaceous proliferations: sebaceous hyperplasia (7), sebaceous adenoma (8), sebaceoma (5), sebaceous carcinoma (7). We also stained 67 tumors with clear cell change: basal cell carcinoma (8), squamous cell carcinoma (8), hidradenoma (7), desmoplastic trichilemmoma (2), trichilemmoma (10), trichilemmal carcinoma (3), clear cell acanthoma (9), atypical fibroxanthoma (1), syringoma (8), trichoepithelioma (1), metastatic renal cell carcinoma (2), and nevi with balloon cell change (8). Nuclear factor XIIIa (AC-1A1) staining was present in 100% of sebaceous proliferations; 96% displayed strong staining. Non-sebaceous clear cell tumors were negative or only weakly positive with factor XIIIa (AC-1A1) in 95.5%; only 4.5% showed strong staining. This suggests that strong nuclear factor XIIIa (AC-1A1) staining is a sensitive and specific marker of sebaceous neoplasms vs. other clear cell tumors.

Fibro epithelial Polyp (FEP) is a polypoid outgrowth of epidermis and dermal fibro vascular tissue. This polyp is most commonly found in oral cavity, neck and axilla, though any skin fold may be affected like groin area. We describe a case of a 25-year-old male patient with a growth over the anterior rugae region of hard palate since 3 years. Based on histological appearance, diagnosis of sebaceous gland hyperplasia in fibroepithelial polyp was given which itself is a rare entity, and in our case, it was encountered at the rarest of sites.

Pathologists who find ectopic glands on the glans and/or on the prepuce, often describe them as Tyson's glands. In this regard, the term Tyson's glands can be replaced by two different descriptive expressions: papillomatosis corona penis and ectopic sebaceous glands. A 15-year-old Caucasian male patient presented to our Institute with multiple and asymptomatic circular skin colored-to-yellowish papules at the level of the foreskin, also affecting the shaft of the penis, where they assumed a linear feature. The histological examination revealed hyperplastic and dilated sebaceous glands, while in some areas these glands showed also a direct attachment with the epidermis. A lymphocytic infiltrate was also observed in one of the two specimens. A final diagnosis of linear ectopic sebaceous hyperplasia of the penis was made. According to the current report, the ectopic sebaceous hyperplasia of the penis can have a circular and a linear patter, as well as the presence and the absence of a lymphoid infiltrate. A correct clinical and pathological diagnosis are necessary to avoid unnecessary treatments and worries in the patients. In fact, not infrequently, this condition is confused with dermatological diseases as molluscum contagiosum, epithelioid granuloma, lymphangioma circumscriptum, multiple syringomas, lichen planus, and bowenoid papulosis.

We herein report a case of hair follicle nevus, a rare hamartoma found on the face and showing follicular differentiation, which was associated with sebaceous hyperplasia. Dermoscopy of the lesion showed yellow globules surrounded by crown vessels/telangiectasias and scattered tiny hairs. Histopathological investigation revealed hyperplasia of the sebaceous glands and proliferation of well-differentiated vellus hair follicles. These pathological findings were thought to correspond to the yellowish globules and tiny hairs observed under dermoscopy. Hair follicle nevus associated with sebaceous hyperplasia is extremely rare; however, dermoscopic examination can suggest an appropriate diagnosis. The present case proved the diagnostic usefulness of dermoscopy for cutaneous tumors with hair follicular and sebaceous glandular differentiation.

Pachydermoperiostosis is a rare hereditary disease, which presents with the cutaneous manifestations of pachydermia and cutis verticis gyrata. Histological findings in pachydermia frequently include dermal edema, mucin deposition, elastic fiber degeneration, dermal fibrosis and adnexal hyperplasia. However, the severity of these findings varies between clinical reports, and a systematic multiple‐case clinicopathological correlative analysis has not been performed to date. In the present study, we reviewed the skin biopsy specimens obtained from the pachydermia of six pachydermoperiostosis patients. The severity of the characteristic histological features was semiquantitatively evaluated and correlated with the grade of pachydermia. Dermal edema, mucin deposition and elastic fiber degeneration were observed in all cases. Patients with severe pachydermia had sebaceous gland hyperplasia and fibrosis. These results suggest that the triad of mucin deposition, dermal edema and elastic fiber degeneration are found from very early stage pachydermia, and could be considered diagnostic findings. To ensure an earlier diagnosis of pachydermoperiostosis, a biopsy should be taken when a patient has grade 1 pachydermia to determine the presence of this histological triad.

Purpose: Considerable focus has recently revealed the importance of p53 in sebaceous carcinoma (SC). This study investigates the utility of p53 as an immunohistochemistry (IHC) marker for differentiating benign and malignant sebaceous tissues and reports the clinical characteristics of patients diagnosed with SC at Mount Sinai Hospital (MSH). Methods: A retrospective chart analysis of 102 patients with SC was performed in addition to a histopathological examination of benign and malignant sebaceous tissues. Immunohistochemistry was performed in 30 cases of SC, 4 cases of sebaceous hyperplasia, 4 cases of sebaceous epitheliomas, and 3 cases of sebaceous adenoma. A separate outpatient cohort was used to compare the clinical and histologic features of eyelid lesions. This included 31 available cases with histologic descriptions of SC. The clinical features of 20 SC cases, 25 BCC cases, and 21 chalazia cases were available and compared from this outpatient cohort. Data collected included age, gender, lesion anatomical location, histopathologic descriptions, and percentage of p53 positive sebocytes. Results: Of the 102 SC cases at MSH, the mean age was 69 years, males composed 58%, and 59% were periorbital or orbital. Positive p53 staining without atypia was reproducibly observed at cell membranes in all cases of sebaceous hyperplasia. Using a standardized p53 grading system used at MSH, the average p53 staining grade for SC and epithelioma was calculated to be 2.3 ± 0.7 and 1 ± 0.7, respectively (p=0.002). An outpatient cohort revealed that 65% of SC was found on the lower eyelid and 84% of BCC was on the upper eyelid. The most common histologic features seen in SC were nuclear atypia (61%) and cytoplasmic vacuoles (55%). Conclusions: This study provides the first comprehensive staining profile of p53 in benign and malignant sebaceous tissues. We also report for the first time that membrane p53 staining was helpful and appeared to be highly specific for identifying sebaceous hyperplasia. p53 staining was also helpful for identifying SC and intraepithelial spreading tumor cells. The clinical and histologic characteristics of specific eyelid lesions in an outpatient setting are also shared. Lastly, this work incorporates the latest research to synthesize IHC recommendations for improving SC detection.

Sebaceous hyperplasia (SH), a common, benign condition of sebaceous gland, presents most commonly over face. Lesions are usually described as asymptomatic, soft, discrete, and yellow with a surface that ranges from smooth to slightly verrucous. The pathogenesis is not fully understood. It does not require treatment, but many time lesions can be cosmetically unfavorable than, need to be destroyed or excised. A case of 23-year-old male presenting with the skin colored to hyperpigmented linear hyperkeratotic plaque mimicking a wart, over the right ear is presented here, which was diagnosed as SH.

Summary Aims Separation of sebaceous adenoma, sebaceoma and well differentiated sebaceous carcinoma is a clinically important distinction which relies on a number of subjective criteria. In routine practice we had noted significant interobserver variability in the classification of these lesions. This study sought to determine the degree of interobserver variability between general surgical pathologists and dermatopatholo- gists in the diagnosis of well differentiated cutaneous sebaceous neoplasms. Methods We circulated 61 examples of well circumscribed cutaneous sebaceous neoplasms to nine pathologists, including dermatopathologists and general surgical pathologists who were asked to submit a diagnosis for each case. Fleiss’ kappa statistic was used for assessment of interobserver agreement. Results We found that only seven cases (11%) had consensus agreement across all nine pathologists. Many cases had multiple diagnoses suggested, with three or more submitted diagnoses in 26 cases (43%), while 38 cases (62%) were diagnosed as sebaceous carcinoma by at least one pathologist. There was marked variability amongst the individual pathologists in the proportion of cases diagnosed as carcinoma, ranging from 5% to 57% of cases. Fleiss’ kappa statistic for all pathologists across all diagnostic categories was 0.44, amounting to only fair to moderate agreement. Conclusions These data indicate that there is substantial interobserver variability in the diagnosis of well circumscribed sebaceous neoplasms. This was seen in both the separation of benign and malignant lesions, as well as in the classification of the benign entities. This interobserver variability is likely to have significant clinical implications in terms of potential for over- or under-treatment, as well as in selection of cases for mismatch repair protein evaluation.

In the breast, sebaceous glands can be seen at the tip of the nipple or as 10 to 15 small rounded elevations in the areola. These structures can undergo atrophy with age, being of little importance in medical practice since pathological lesions develop rarely at this site. However, sebaceous hyperplasia at this level may lead to confusion with breast Paget's disease.A 67-year-old woman sought medical attention for bilateral multiple papules coalescing into plaques on areolas, which were noticed two [...]

Presenile diffuse familial sebaceous hyperplasia (PDFSH) presents as extensive yellowish papules with central umbilication on the face without involvement of periorificial regions and occurs in adolescents or young adults with a positive family history. Thirteen cases of PDFSH have been reported in the English-language published work, 10 of which responded to oral isotretinoin from 0.5 to 1 mg/kg per day but recurrences were often observed. Herein, we report two cases of PDFSH, which were successfully managed without recurrence with prolonged low-dose isotretinoin (0.2 mg/kg per day, a cumulative dose of 41 and 64 mg/kg, respectively). Treatment protocols among different published works were reviewed to verify the efficacy of isotretinoin.

Cyclosporine-induced sebaceous hyperplasia (SH) is a well-documented entity, occurring in up to 30% of renal transplant patients treated with cyclosporine and has also been reported to occur following heart or hematopoetic stem cell transplantation (HCST). Cyclosporine has a stimulatory effect on undifferentiated sebocytes, resulting in the clinical and histologic findings in these patients. Sebaceous hyperplasia most commonly presents as asymptomatic papules over the face, chest, or groin. Herein we describe a case of a 27-year-old man who developed facial sebaceous hyperplasia five months after completing cyclosporine therapy for cutaneous graft versus host disease (GVHD) following HSCT.

Diffuse sebaceous-gland hyperplasia is a rarevariant of sebaceous-gland hyperplasia that isdistinct from the well-known circumscribed type.The term presenile sebaceous hyperplasia has beenutilized to describe this entity that is distinguishedby specific features, which include confluence oflesions that results in the formation of large plaqueson the face, the sparing of periorificial regions, andhighly functional glandular hyperplasia that resultsin excessive sebaceous secretion. We present a43-year-old woman with monomorphous, skincoloredand yellow, smooth 1- to-3-mm papules,some with central umbilication, that spare theperiorificial zones. Histopathologic examination wassuggestive of diffuse sebaceous-gland hyperplasia.Differential diagnosis of this condition is broad andincludes syndromes that are associated with multiplefacial papules and malignant conditions, such asMuire-Torre syndrome and Cowden syndrome. Itis important to be aware of this condition in orderto consider appropriate treatment options, such asisotretinoin and to avoid unnecessary diagnostictests.

The human sebaceous gland is a microscopic branched type multiacinar gland been present everywhere on the body except on the palms and soles, whereas they are sparsely located on the dorsum of hands and feet. Several medical conditions are related with sebaceous gland pathology, such as acne, sebaceous hyperplasia, sebaceous adenoma and sebaceous carcinoma. Acne is a common, complex, chronic disorder of the human pilosebaceous unit that mostly occurs in adolescence and young adulthood. The sebaceous gland plays an exquisite role in the initiation of the disease. The multifactorial nature of the pathogenesis of acne includes increased sebum production, alteration of the quality of sebum lipids, inflammatory processes, interaction with neuropeptides and dysregulation of the hormone microenvironment, follicular hyperkeratinization and inflammation maintained by Propionbacterium acnes products within the follicle. On the other hand, the sebaceous gland, as a major and critical compartment of human skin, is also affected through ageing, both intrinsic and extrinsic, which lead to distinct clinical and histological changes. Intrinsic ageing of the sebaceous gland is determined primarily by genetic factors and hormonal status, with androgens playing a major role. A clinical manifestation associated with intrinsic ageing changes is skin xerosis. Extrinsic ageing of human sebaceous gland is mainly caused by accumulating UV irradiation, especially UVA. Photoageing of sebaceous gland is expressed with a wide spectrum of benign and malignant sebaceous tumours, such as sebaceous hyperplasia, sebaceous carcinoma and Muir-Torre syndrome. This review will focus on the pathogenesis of the most common sebaceous gland diseases and their molecular pathways which may represent future pharmaceutical targets.

Under the right conditions, dermoscopy allows us to observe the vascular features of many different types of skin lesions. The visualization and identification of vessels with a characteristic morphology can be the key to diagnosis, especially in hypopigmented lesions in which the typical pigmented structures are not visible. Some of the more characteristic associations are the presence of crown vessels in sebaceous hyperplasia, arborizing telangiectasias in basal cell carcinoma, comma-shaped vessels in intra- dermal and compound nevi, dotted vessels in Spitz nevi and melanoma, and hairpin vessels in seborrheic keratoses. The recognition of distinctive vascular features can be of great help in the diagnosis of many types of skin lesions, and very often such patterns are the only key to the diagnosis of melanoma. © 2011 Elsevier Espana, S.L. and AEDV. All rights reserved.

Areolar hyperplasia is only reported when exaggerated, and even so, exaggerated areolar sebaceous hyperplasia is rare. We have recently seen a case of areolar sebaceous hyperplasia in a 32-year-old woman with Donohue syndrome (leprechaunism), who also had an invasive ductal carcinoma in the same breast. The patient showed typical "elfin-like" face with wide nostrils and thick lips, large and low-set ears, and dysplastic nails. The areola showed a yellowish thickened plaque of 5-cm diameter that corresponded to a hyperplasia of the sebaceous glands. Immunohistochemistry for the mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) was performed on the sebaceous hyperplasia and on the breast carcinoma, and no lack of expression of the markers was evidenced. We have found no other reported case of areolar sebaceous hyperplasia either in cases of breast carcinoma or in cases of leprechaunism.

This retrospective survey was undertaken between 2002 and 2007 on samples from dogs residing in Grenada. The objectives of the study were to identify the most common histologic types of canine cutaneous tumors, determine the relative frequency of each tumor type, and compare results to reports from other regions. In a series of 225 skin masses examined, the proportion of neoplasms was 72% whereas nonneoplastic tumors accounted for 15.6%, and inflammatory conditions constituted 12.4%. There were 10 types of nonneoplastic tumors with hamartomas being the most common (28.5%), followed by sebaceous hyperplasia (25.7%) and fibroepithelial polyps (22.8%). The 10 most common cutaneous neoplasms were hemangiosarcomas (19.1%), histiocytomas (8.6%), melanocytomas (8%), mast cell tumors (6.8%), lipomas (6.8%), hemangiopericytomas (6.2%), papillomas (5.6%), fibrosarcomas (5.6%), hemangiomas (4.9%), and squamous cell carcinomas (4.3%). Tumors of vascular origin and transmissible venereal tumors were more common in dogs in our study than reported from other regions.

The male nipple-areola-complex (NAC) is a residual organ without physiologic functions in the male. It possesses similar hormone sensitivity and sexual sensitivity as the female organ. The location of the NAC on the chest wall with respect to other surface features is relevant for the male appearance. All known disseminated skin diseases may involve the nipple and areola. A number of specific localized diseases have been described in the literature, such as mammillary eczema, demodicidosis, lymphadenosis cutis benigna, nevoid hyperkeratosis, and thelalgia. Special attention is required if nipple discharge is observed. Areolar sebaceous hyperplasia and nearly all kinds of benign cutaneous tumors occur on the nipple and areola. Malignant tumors such as basal cell carcinoma, melanoma, Paget disease and other forms of breast cancer may also be found. In addition, aberrant mammary tissue may occur with a broad clinical spectrum, while absence of the nipple is an unusual observation and occurs in rare syndromes. The association of aberrant mammary tissue with urinary tract malformations has not been confirmed.

Occurrence of ectopic sebaceous glands in the uterine cervix is a rare, unusual, and an incidental finding. Microscopically, sebaceous elements are typically situated high in the submucosa without an accompanying hair follicle (so-called free sebaceous glands). They are suggested to give rise to rare cases of sebaceous carcinoma in this location but are otherwise of little clinical significance. We report marked hyperplasia of ectopic sebaceous glands in the ectocervix, which produced detectable lesions on colposcopy. Histopathological examination showed foci of ectopic sebaceous glands located in the submucosa consisting of numerous, variably sized, clustered sebaceous lobules. Each sebaceous lobule was composed of a peripheral layer of germinative cells and centrally located, mature sebocytes with a multivacuolated cytoplasm and round or scalloped nuclei. In one area, there were over 20 sebaceous lobules that were partly connected to a sebaceous duct. To our knowledge, similar changes in ectopic sebaceous glands in the uterine cervix have not been reported till date.

Dermoscopy is a noninvasive tool that can be helpful in the diagnosis of nonpigmented skin tumors. This is because dermoscopy permits the visualization of key vascular structures that are usually not visible to the naked eye. Much work has concentrated on the identification of specific morphologic types of vessels that allow a classification into melanocytic versus nonmelanocytic and benign versus malignant nonpigmented skin tumors. Among a broad spectrum of different types of vascular patterns, six main morphologies can be identified. These are comma-like, dotted, linear-irregular, hairpin, glomerular, and arborizing vessels. With some exceptions, comma, dotted, and linear irregular vessels are associated with melanocytic tumors, while the latter three vascular types are generally indicative of keratinocytic tumors. Aside from vascular morphology, the architectural arrangement of vessels within the tumor and the presence of additional dermoscopic clues are equally important for the diagnosis. This article provides a general overview of the dermoscopic evaluation of nonpigmented skin tumors and is divided into two parts. Part I discusses the dermoscopic vascular patterns of benign and malignant melanocytic skin tumors. Part II discusses the dermoscopic vascular patterns of benign and malignant nonmelanocytic nonpigmented skin tumors. In each part, additional special management guidelines for melanocytic and nonmelanocytic nonpigmented skin tumors, respectively, will be discussed.

Sebaceous neoplasia comprises a spectrum ranging from benign to malignant. Proper histological identification is important for treatment, prognosis and potential association with the Muir–Torre syndrome (MTS). Our increased understanding of the significance and pathogenesis of these tumours has led to improved risk stratification, screening recommendations, and treatment of patients with an initial presentation of a sebaceous tumour. This review focuses on the diagnostic and histological features of sebaceous lesions, the MTS, and recent insights into the molecular pathogenesis of sebaceous tumorigenesis.

Background The term "induction" has been used to designate epidermal changes above dermatofibroma. Whereas follicular differentiation has been reported frequently, sebaceous hyperplasia above dermatofibroma is considered a rarity. Objective To characterize all changes overlying dermatofibroma and to determine their frequency. Methods Sections cut from 210 consecutive examples of dermatofibroma were stained with hematoxylin and eosin and analyzed for the presence or absence of induction, for the type of change induced, and for features associated with these findings. Results The epidermis above dermatofibromas was acanthotic, simulating seborrheic keratosis in 62.9% of the cases, and areas of clear and pale cells similar to those of clear cell acanthoma were seen in 18.6%. Induction of adnexal differentiation was encountered in 41% of the cases. Follicular differentiation was seen in 10.9%, all of which showed some follicular germinative cells. In 9.5%, follicular germinative cells were present together with well-circumscribed mesenchymal papillae. In 4%, formation of a complete hair follicle was encountered. In 16.7% of the dermatofibromas, induction of sebaceous lobules was encountered, whereas sebaceous differentiation in the form of mantles was seen in 25.7% of the cases. Not uncommonly, sebaceous structures were arranged in a reticulate pattern similar to that seen in reticulated acanthoma with sebaceous differentiation (12%). Conclusions Induction of adnexal structures is more common than currently perceived. Especially, induction of immature and mature sebaceous structures seems to be underrecognized.

The sebaceous gland is renewed throughout adult life and homeostasis of this particular organ is controlled by a precise interplay of hormones, cytokines, signalling molecules and mediators of the lipid metabolism. Although the true function of sebaceous glands has yet to be fully determined, recent evidence demonstrates that normal homeostasis of the sebaceous gland and functional lipid metabolism of sebocytes is crucial for maintenance of the skin barrier. In addition, analysis of mutant mouse models revealed a close interdependency of the sebaceous gland with hair follicles because abnormal morphogenesis of sebaceous glands often results in degeneration of hair follicle structures. Anomalous regulation of sebaceous glands is involved in the pathogenesis of acne, one of the most prevalent human diseases, or could lead to formation of sebaceous hyperplasia and tumours. This review highlights some of the recent findings on the importance of signalling pathways controlling morphogenesis and differentiation of the sebaceous gland in vivo.

The diagnosis of sebaceous carcinoma presents an important challenge to both clinicians and pathologists, as many cases are initially misdiagnosed both clinically and histopathologically, potentially leading to adverse medical and legal outcomes. The distinction of sebaceous carcinoma from benign sebaceous proliferations and other tumors is therefore of utmost importance, and immunohistochemistry may be useful in this differential. We studied the expression of D2-40 (podoplanin) by immunohistochemistry to determine if it can aid in this differential diagnosis and to evaluate the possibility of lymphangiogenesis in sebaceous carcinoma. A total of 36 cases of sebaceous lesions, including 16 sebaceous carcinomas, 7 sebaceous adenomas, 6 sebaceomas, and 7 cases of normal glands and sebaceous hyperplasia, and 17 cases of basal cell carcinoma and 10 cases of squamous cell carcinoma, were also examined. We found no significant increase in tumor lymphangiogenesis by semiquantitative scoring of lymphovascular density per square millimeter of tumoral/peritumoral stroma in sebaceous carcinoma versus benign sebaceous proliferations. However, D2-40 staining showed a different pattern in the benign tumors, which were positive only in the basaloid cells (most pronounced in sebaceoma), versus sebaceous carcinoma, which was either negative or focally positive in a haphazard pattern in most cases, although some cases of basaloid sebaceous carcinomas showed strong positivity. We also found D2-40 to be only weakly and focally positive in basal cell carcinoma and weakly to moderately positive in squamous cell carcinoma, which showed increased staining with decreased differentiation. Therefore, overall, D2-40 is, of limited diagnostic utility in sebaceous lesions but may be useful in distinguishing sebaceoma and basaloid sebaceous carcinoma from basal cell carcinoma.

Cutaneous sebaceous neoplasia is known to exhibit a high degree of DNA mismatch repair (MMR) deficiency leading to microsatellite instability and these tumors can be markers of the Muir-Torre syndrome and internal malignancy. Other tumors, such as colonic carcinoma, show tendencies toward particular histologic features and sites of involvement correlating with MMR deficiency. There are few comprehensive studies of unselected cutaneous sebaceous neoplasms. To address this gap in knowledge, we examined 94 sebaceous neoplasms from 92 patients and 17 sebaceous hyperplasia controls using immunohistochemistry for MLH1, MSH2, and MSH6. Our results indicate that MMR deficiency is significantly associated with anatomic location (more frequently in the trunk and extremities as compared with head and neck), tumor type (more often in adenoma compared with carcinoma within the head and neck region), and architecture (keratoacanthomalike). No correlation between cystic change and MMR deficiency was noted. Cutaneous sebaceous neoplasia has tendencies toward certain tumor types and anatomic distribution based on MMR status analogous to that seen in colonic carcinomas and other tumors. These may be helpful indicators for further workup for the Muir-Torre syndrome.

The OCT4 transcription factor is a marker of pluripotency and is present in embryonic stem cells, primordial germ cells, and several neoplasms including seminoma, dysgerminoma, and embryonal carcinoma. Recently, immunohistochemical expression of OCT4 protein has been described in the cells within the basal layer of normal human and canine epidermis. We have examined a series of basal cell carcinomas and adnexal tumors of related histogenesis, in an effort to corroborate the above findings and to assess for expression of OCT4 protein in neoplasia of the infundibulo-apocrine-sebaceous unit. We analyzed OCT4 expression in 115 cutaneous specimens including 26 basal cell carcinomas, 12 benign follicular tumors (10 trichoepitheliomas and 2 trichoblastomas), 10 benign apocrine tumors, 12 sebaceous hyperplasia lesions, 10 sebaceous adenomas, 4 sebaceous carcinomas, 13 nevi sebacei of Jadassohn, 8 squamous cell carcinomas (including one spindle-cell squamous cell carcinoma), 8 compound melanocytic nevi, 5 Merkel cell carcinomas, 3 pilar cysts, 1 scar, 2 nonspecific, mild superficial perivascular dermatitis specimens, and 1 non-scarring alopecia. All 115 specimens examined were negative for OCT4 expression as was adjacent or overlying epidermis and follicular epithelium including the bulge region. In contrast to previous studies, our data indicate that the OCT4 expression is not retained in cutaneous neoplasms derived from basal epidermis or related adnexal neoplasms, including lesions of the scalp.

Summary Sebaceous tumours include hyperplasia, adenoma, sebaceoma and carcinoma. Importantly, the latter three are potential markers of Torre–Muir syndrome, which is the hereditary association of sebaceous neoplasia and internal malignancy – most commonly colorectal carcinoma. The diagnostic features, differential diagnosis, molecular diagnostics and recent advances in our understanding of the pathogenesis of this rare group of tumours are discussed along with Torre–Muir syndrome and recommendations for screening for this important association.

Background: Recent studies have demonstrated telomerase expression in ophthalmologic sebaceous carcinoma and have suggested possible diagnostic utility in distinguishing these neoplasms from sebaceous adenomas. The aim of this study was to evaluate telomerase expression via human telomerase reverse transcriptase (hTERT) immunohistochemical staining in a spectrum of sebaceous lesions of the skin. Methods: Paraffin-embedded sections from sebaceous hyperplasia (11), nevus sebaceus (22), sebaceous adenoma (19), sebaceoma (11), and sebaceous carcinoma (14) were evaluated for intensity (0 to 3+) and pattern of anti-hTERT staining. Results: Strong (2 to 3+) hTERT staining was observed in nucleoli of germinative cells and immature sebocytes in all sebaceous lesions, whereas mature sebocytes were negative. The distribution pattern paralleled features seen by routine haematoxylin and eosin-stained sections. Conclusions: All hyperplastic and neoplastic sebaceous skin lesions expressed hTERT in this immunohistochemical study. The pattern of staining was predictive of the histologic pattern of the process but does not significantly add to our diagnostic armamentarium of sebaceous lesions.

Toxic epidermal necrolysis (TEN) is a severe cutaneous adverse drug reaction leading to extensive sloughing of the skin. Late cutaneous complications such as pigmentation disorders are frequently reported. In this report, we present particular facial cutaneous sequelae with histological analysis after TEN. Two young patients who had survived TEN presented permanent multiple hypopigmented papules on the face affecting their quality of life. Histological analysis revealed areas of scarring, dystrophic microcalcifications and sebaceous hyperplasia. Late cutaneous sequelae are well documented; however, the physiopathological mechanisms leading to different clinical presentations remain unknown. We suggest that the destruction of the hair follicle by necrolysis leads to secondary dermal microcalcifications, scarring and sebaceous hyperplasia. Further studies are needed for a better understanding of these findings.

Background The Muir–Torre syndrome (MTS), a variant of Lynch syndrome (LS), is characterized by the presence of sebaceous skin adenomas and/or carcinomas and keratoacanthomas associated with visceral malignancies. Fordyce granules (FGs) are oral mucosal lesions previously found in association with LS. The aim of this study was to analyze the specific frequency of FGs in sporadic individuals and gene carriers patients with MTS of known mismatch repair genes mutations. The secondary aim was to characterize FGs by means of reflectance confocal microscopy (RCM). Methods A total of 13 patients belonging to nine different genetically unrelated MTS kindreds (MLH1 gene mutation n = 2; MSH2 gene mutation n = 11) and 140 genetically unrelated healthy controls were examined. Depending on the clinical examination of the oral mucosa surface, subjects were categorized as either FGs positive or FGs negative. Results FGs were diagnosed in 13 of 13 (100%) of MMR gene carriers patients with MTS vs. 9 of 140 (6.4%) controls. The most common site for FGs in MTS was the vestibular oral mucosa, compared with the gingival mandibular and retromandibular pad in controls. RCM examination found multiple sebaceous acinar cells that appear as round or oval hyper-refractive globules and that create a lobular aspects of the sebaceous glands defined as ‘moruliform’ or ‘berry-like’ structures. Conclusions Clinical and RCM evidences of our study suggest that an activation of the sebaceous glands system occurs in patients with MTS. Fordyce granules and intra-oral sebaceous hyperplasia may constitute an additional clinical parameter, which may be adopted to distinguish individuals with highest likelihood of being affected from MTS.

Background Preliminary studies have described morphological features of basal cell carcinoma (BCC) imaged by high-definition optical coherence tomography (HD-OCT) and suggested that this technique may aid in its diagnosis and management. However, systematic studies evaluating the accuracy of HD-OCT for the diagnosis of BCC are lacking. Objective The aim of this study was to identify three-dimensional (3-D) HD-OCT features able i) to distinguish BCC from clinical BCC imitators and ii) to discriminate between the most common BCC subtypes. Based on these particular features, a diagnostic algorithm will be suggested. Method A total of 50 histopathologically confirmed BCCs (18 superficial, 19 nodular, 13 infiltrative) were imaged by HD-OCT at the centre of the lesion prior to standard surgical excision and subsequent histopathological analysis. Fifty images of clinical BCC imitators were also retrieved as a ‘pitfalls’ group. Results The simultaneous presence of grey/dark subepidermal (hemi-spherical) or intradermal lobulated structure(s) presenting a typical cockade feature in both HD-OCT modes was a significant feature for BCC diagnosis. Features discriminating between BCC subtypes were location of the roof of BCC lobules, vascular pattern of the papillary plexus and stretching effect on the stroma. Clinical BCC imitators such as actinic keratosis, compound and intradermal naevi, amelanotic melanoma, sebaceous hyperplasia and small haemangioma could be differentiated from BCC by means of HD-OCT. Conclusion This study provides a thorough description of 3-D HD-OCT features that can permit discrimination of BCC from clinical BCC imitators and differentiation of BCC subtypes. Based on these features, a diagnostic algorithm is proposed which requires additional validation, but enhances current understanding of the morphological correlates of HD-OCT images in skin.