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Eruptive melanocytic nevi (EMN) are rare multiple benign melanocytic nevi that develop within a few months. The phenomenon has been associated with a variety of dermatologic and systemic conditions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, epidermolysis bullosa, Addison disease, human immunodeficiency virus infection, and internal malignancy, among others. It also is commonly attributed to medications, particularly immunosuppressive and chemotherapeutic agents. We report a case of EMN in a 50-year-old man undergoing azathioprine therapy for antisynthetase syndrome.

Primary cutaneous apocrine carcinomas are uncommon malignant neoplasms that can be difficult, if not impossible, to distinguish histologically from metastatic breast carcinomas. We present the case of a 71-year-old man with a 5-year history of extensive ulcerated plaques on the posterior neck and posterior scalp. Biopsy revealed a poorly differentiated infiltrating adenocarcinoma consistent with either primary cutaneous apocrine carcinoma or occult metastatic breast carcinoma. Immunohistochemical analysis demonstrated positive staining for cytokeratin (CK) 7, estrogen receptor, and progesterone receptor, and negative staining for p63, podoplanin, CK20, and thyroid transcription factor 1. Extensive radiologic imaging studies showed no evidence of occult breast or other internal malignancies. Based on the indolent clinical course, lack of evidence for an internal primary site, and immunohistochemical staining, the lesion was determined to be consistent with a cutaneous neoplasm with features of apocrine differentiation. This case highlights the distinction between apocrine carcinoma and other primary adnexal carcinomas for which p63 and D2-40 have been reported to be sensitive and specific markers but are negative in apocrine carcinomas.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a distinct type of peripheral T-cell lymphoma, which has gained recognition over the past decade. The disease presents complex clinical, pathologic, and immunohistochemical features, which warrant awareness by dermatologists, dermatopathologists, hematopathologists, hematologists, oncologists, and internists. SPTCL was initially included as a provisional entity in the Revised European-American Lymphoma classification, followed by the European Organization for Research and Treatment of Cancer classification as a primary cutaneous lymphoma, and subsequently as a distinct entity by the World Health Organization classification. It is known that patients diagnosed with SPTCL usually respond poorly to therapy, and the tumor progresses aggressively. Data from recent studies in a series of cases of SPTCL by the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Group have further identified SPTCL as a heterogeneous disease entity, which comprises an alpha/beta subtype (SPTCL-AB) and a gamma/delta subtype (SPTCL-GD). The latter has recently been included in the entity of "cutaneous gamma/delta T-cell lymphoma" by the World Health Organization, Pathology and Genetics of Skin Tumours. The clinical, histologic, and immunophenotypic data, treatment, and prognosis, appear different in the 2 subtypes of SPTCL. We report a case of fatal SPTCL-GD (cutaneous gamma/delta T-cell lymphoma), with detailed clinicopathologic features, immunohistochemical studies, treatment, and clinical course. In view of its aggressive behavior, identification of this disease is critical for proper management and treatment.

Toker cells are epithelial clear cells found in the areolar and nipple areas of the breast, vulvar region, and other apocrine gland-bearing areas of the skin. Toker cells have been implicated in the pathogenesis of clear cell papulosis, cutaneous hamartoma with pagetoid cells, and rare cases of primary extramammary Paget disease (EMPD) but not in secondary EMPD with underlying adenocarcinoma. The pathogenesis of primary EMPD is not well defined. We report a case of multicentric primary EMPD with evidence of Toker cell proliferation and nonaggressive biologic behavior in a 63-year-old white man. A detailed description of the morphologic and biologic features of Toker cells and their possible carcinogenetic links also are discussed. Based on the observation and follow-up of our patient, we hypothesize that multicentric primary EMPD starts with Toker cell hyperplasia and can potentially evolve to carcinoma in the genital region.

Large papillomatous lesions clinically resembling verrucous carcinoma may be caused by viruses other than human papillomavirus. We report a case of recurrent vegetations covering the entire vulva in a pregnant patient with common variable immunodeficiency. Herpes simplex virus was recovered from these lesions. The patient did not respond to intravenous acyclovir, but her lesions dramatically healed with two courses of intravenous foscarnet. Repeated biopsies may prove necessary in cases such as this to ensure proper diagnoses.

A 14-year-old previously healthy boy was referred to the pediatric infectious disease clinic for evaluation of painful nodules, which had been present for 2 weeks, on both soles of his feet. The nodules were first noted 2 weeks after returning to the United States from a 1-month family vacation to visit relatives in his native Guyana, South America. The foot nodules were unimproved after application of topical Neosporin and a 1-week course of oral trimethoprimsulfamethoxazole prescribed by his primary care physician. The nodules were nonpurulent but expressed serosanguinous fluid. Neither he nor other family members had developed skin lesions during the trip itself. The patient denied systemic symptoms, including fever, rash, headache, respiratory, or joint complaints. He had no significant past medical history or drug allergies. The patient denied swimming in fresh or sea water, insect bites, or animal contact, and he denied sexual activity; however, he did walk with sandals in sandy soil. On physical examination, his vital signs were within normal limits. The examination was notable only for nodules to the soles of his feet bilaterally (as shown in Figure 1). He had approximately 20 firm, nodules (1 × 2 cm) on his right foot and 9 discrete (1 × 2 cm) nodules on his left. His physical examination was otherwise unremarkable. After dermatology consultation, an excisional skin biopsy was performed with microscopic examination of the biopsy specimens, which confirmed the visual diagnosis.

We report a case of Merkel cell polyomavirus detection in the skin of a patient with epidermodysplasia verruciformis (EDV) and a family history remarkable for an unusual inheritance pattern for EDV.

Keratoacanthomas are benign skin tumors that grow rapidly but eventually regress. They occur most commonly in sun-exposed skin and are histologically remarkably similar to squamous cancers. Since mutations of the p53 tumor suppressor gene are found frequently in cutaneous squamous cell carcinomas, we hypothesized that p53 mutations might contribute to the development of keratoacanthomas. To address this question, we did p53 immunohistochemistry with a polyclonal rabbit antiserum, CM-1, that binds both mutant and wild-type p53 proteins. Although wild-type p53 protein degrades rapidly and is generally undetected by immunohistochemistry, mutant p53 protein has a longer half-life and accumulates to detectable levels. We tested 26 formalin-fixed keratoacanthomas and 4 normal skin biopsies. Positive nuclear staining was detected in 20 of 26 (77%) of the keratoacanthomas and in none of the normal skin samples. Nuclear staining occurred in the outermost layer of the neoplasms and not in the keratin-filled central cores. Since nuclear p53 protein within a cutaneous squamous cell carcinoma usually correlates with missense mutation, these data suggest that p53 mutations contribute to the development of this benign neoplasm. The histologic similarity to squamous cell carcinoma and the accumulation of p53 protein suggest progression toward malignancy, but the invariable regression of these tumors suggests an arrest at some point in multistage carcinogenesis. If this model is correct, then genetic analysis of keratoacanthomas may provide clues to the later stages of squamous carcinogenesis including local invasion and metastasis.

We present a rare case of metastatic adenocarcinoma of the parotid gland to the skin. Reviewing the histologic features of the primary parotid gland and comparing the microscopic sections and immunohistochemical studies, we concluded the skin tumor to be metastases from the parotid adenocarcinoma. By histologic examination alone, it is difficult to distinguish an eccrine sweat gland carcinoma from a metastatic carcinoma of the salivary gland. Immunohistochemical analysis may not be conclusive. Therefore, clinical history and clinicopathologic correlation are essential in arriving at an accurate diagnosis in these cases.

Trichodysplasia spinulosa (TS) is a rare, disfiguring skin condition that affects immunosuppressed patients, universally involving the central face. New data point to the recently discovered TS-associated polyomavirus (TSPyV) as the causative agent.We report a case of TS in a 48-year-old African American man after renal transplant; via polymerase chain reaction and sequencing, confirm the detection of TSPyV in lesional skin; and report the novel detection of TSPyV DNA in renal allograft tissue. Results of polymerase chain reaction analysis were negative for Merkel cell polyomavirus in lesional skin. Fifteen months later, urine cytologic findings showed morphologic evidence of a urinary tract polyomavirus infection. Results of SV40 immunohistochemical analysis were negative in lesional skin, renal allograft, and urine specimens.To our knowledge, this is the first reported case in which TSPyV DNA has been detected in extracutaneous tissues and the third with combined ultrastructural and molecular confirmation of the presence of TSPyV in lesional skin. Lack of detection of other pathogenic human polyomaviruses in this patient's skin supports the specific role of this polyomavirus in the genesis of TS. Further basic science studies are needed to determine the exact pathomechanisms of this polyomavirus and to explore possible tumorigenic roles in other skin diseases.

The clinical, morphological and immunohistochemical features of 27 patients with anaplastic large cell lymphoma (ALCL) of CD30-positivc type, with cutaneous lesions as the sole initial clinical manifestation, were analyzed. The neoplasm presented as solitary or multiple, usually ulcerated skin lesions, affecting predominantly elderly patients (median age: 67 years) with a male preponderance (male to female ratio of 6:1). In most patients, there was an excellent response to chemotherapy. The cardinal histological features included diffuse dermal and sub-cutaneous infiltration by large, anaplastic tumor cells, all or nearly all of which showed diffuse, strong membrane staining and frequently a paranuclear, dot-like reaction with the CD30 marker (Ber-H2). Epidermal ulceration, pseudo-epitheliomatous hyperplasia and dermal vascular proliferation were also ob-served.

Balloon cell malignant melanoma (BCMM) is a rare histologic variant of malignant melanoma (MM). Thirty-four patients with BCMM from the files of the Armed Forces Institute of Pathology (AFIP) were studied by means of clinicopathologic correlation and histochemical, immunohistochemical, and ultrastructural methods to better define this entity. The cytoplasmic features of the balloon cells observed in BCMM resemble those noticed in balloon cell nevus (BCN), but the presence of nuclear pleomorphism, atypia, and mitoses and the absence of intervening stroma help distinguish BCMM. The cells also show many histochemical, immunochemical, and ultrastructural features of conventional melanoma cells. Although it is generally believed that balloon melanoma cells represent a degenerative change, the immunohistochemical and electron microscopic findings suggest that the balloon tumor cells are most likely metabolically active melanocytic cells. Microscopically, BCMM also must be differentiated from other clear cell tumors such as clear cell sarcoma (MM of soft parts), hibernoma, xanthoma, sebaceous neoplasms, metastatic renal cell carcinoma, (malignant) clear cell acrospiroma, (malignant) granular cell tumor, granular (clear) cell basal cell carcinoma, clear cell syringoma, and atypical fibroxanthoma. The prognosis of BCMM usually correlates with the tumor thickness similar to that in other histologic types of cutaneous MM. Nineteen (57.5%) of 33 patients with adequate follow-up information died of disseminated tumors from 2 months to 12 years after the initial treatment. Six (18.2%) patients developed local recurrences: four of these patients died of metastasis and two were alive with metastatic tumor at last contact. Five (15.2%) patients were alive with metastatic tumors, and seven (21.2%) were alive without evidence of disease at last contact. Recognition of BCMM is important because of its malignant biologic behavior.

Background: Nephrogenic fibrosing dermopathy (NFD) has emerged as a clinicopathologic entity since 1997 and recently renamed as nephrogenic systemic fibrosis (NSF). The etiology and pathogenesis remain uncertain. Characteristic clinical presentation is described as diffuse thickening and hardening of the skin occurring in patients with renal insufficiency. Typical histological features include proliferation of CD34 positive fibrocytes, increased thick collagen bundles and mucin deposition, without significant inflammatory infiltrate. Variations in clinical presentations have been reported, including papular and plaque-like skin lesions, focal lesion only, as well as systemic involvement. Histological changes can be subtle and non-specific, overlapping with other disease processes and harboring features including calcification and osteoclast-like giant cells with osseous metaplasia. Methods: We reviewed patients with NSF that presented to our dermatology clinic by chart review, clinical examination and histological examination. Skin biopsy specimens were obtained from all cases. Histopathology evaluations were carried out by three dermatopathologists (AD, BS and GK) independently and the features were compared among all the cases. Special stains and immunohistochemistry study were also performed to highlight the histological features. Results: Seven cases of NSF presented with a spectrum of clinical manifestations, from classic diffuse hardening of the skin to localized linear plaques. On histological examination, proliferation of CD34-positive fibrocytes ranged from sparse to dense, collagen bundles ranged from thin to thick, and the interstitial dermal mucin accumulation ranged from scant-patchy to abundant. In addition, the lesion displayed various degrees of vascular proliferation, inflammatory infiltrates and intensities of CD68 and Factor XIIIa staining. Two cases showed extensive dermal calcification and ossification. Conclusion: NSF may present with a spectrum of clinical abnormalities, and exhibit overlapping histopathological features resembling cicatrix and other dermal reparative/regenerative processes. NSF may in fact to be a disorder of aberrant extracellular matrix remodeling in patients with renal insufficiency. Deng A, Bilu Martin D, Spillane A, Chwalek J, St. Surin-Lord S, Brooks S, Petrali J, Sina B, Gaspari A, Kao G. Nephrogenic systemic fibrosis with a spectrum of clinical and histopathological presentation: a disorder of aberrant dermal remodeling.

The diagnosis of skin diseases, particularly inflammatory dermatoses, is based primarily on clinical information. Pathologic examination of the biopsied specimen often serves as a complementary or confirmative part of the diagnosis. However, the clinical diagnosis of skin diseases may be challenging, as the clinical information and appearance of skin lesions invariably overlap. Evidence for a correct diagnosis may be lacking without histopathologic examination of skin biopsies. It is well known that the histologic diagnosis of inflammatory and other skin diseases requires clinicopathologic correlation, and there is evolution of skin lesions into different stages as the diseases progress. Other factors important for accurate dermatopathologic diagnosis are optimum time, best location and preferred techniques of skin biopsy. In searching for available information concerning when, where and how to take skin biopsies, it is noted that there are only limited practical guidelines currently available. We present this review article in hopes that our collective dermatopathologic and dermatologic experience can provide a quick reference for accurate diagnosis and proper management of skin diseases.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a distinct type of peripheral T-cell lymphoma, which has gained recognition over the past decade. The disease presents complex clinical, pathologic, and immunohistochemical features, which warrant awareness by dermatologists, dermatopathologists, hematopathologists, hematologists, oncologists, and internists. SPTCL was initially included as a provisional entity in the Revised European-American Lymphoma classification, followed by the European Organization for Research and Treatment of Cancer classification as a primary cutaneous lymphoma, and subsequently as a distinct entity by the World Health Organization classification. It is known that patients diagnosed with SPTCL usually respond poorly to therapy, and the tumor progresses aggressively. Data from recent studies in a series of cases of SPTCL by the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Group have further identified SPTCL as a heterogeneous disease entity, which comprises an alpha/beta subtype (SPTCL-AB) and a gamma/delta subtype (SPTCL-GD). The latter has recently been included in the entity of "cutaneous gamma/delta T-cell lymphoma" by the World Health Organization, Pathology and Genetics of Skin Tumours. The clinical, histologic, and immunophenotypic data, treatment, and prognosis, appear different in the 2 subtypes of SPTCL. We report a case of fatal SPTCL-GD (cutaneous gamma/delta T-cell lymphoma), with detailed clinicopathologic features, immunohistochemical studies, treatment, and clinical course. In view of its aggressive behavior, identification of this disease is critical for proper management and treatment.

Immune reconstitution inflammatory syndrome (IRIS) encompasses a variety of conditions that occur among HIV-infected patients in a temporal relationship with increases in CD4 cell count as a result of highly active antiretroviral therapy (HAART). Most conditions associated with IRIS are infectious. Malignancies, such as Kaposi's sarcoma, have also been reported. We report a case of sinusitis with presumptive inflammatory pseudotumor as a manifestation of IRIS that occurred 20 weeks after the initiation of HAART.

The dermatologic diagnosis of Rocky Mountain spotted fever (RMSF) is often presumptive; the clinical presentation includes skin rash and febrile illness with or without a clear history of tick bite. The characteristic cutaneous manifestations include a generalized skin eruption with purpuric, blanching or non-blanching macules and papules usually involving the extremities. Although skin biopsies are often performed to confirm the diagnosis, the spectrum of cutaneous histopathology in RMSF has not been well described. We studied a series of 26 cases of RMSF, of which 10 were surgical specimens and 16 were autopsies. The microscopic changes were correlated with the duration of illness. The main histopathologic feature was lymphohistiocytic capillaritis and venulitis with extravasation of erythrocytes, edema, predominantly perivascular and some interstitial infiltrate. Leukocytoclastic vasculitis (LCV) with neutrophilic infiltrate and nuclear dust was seen in 11 of 15 (73%) specimens from involved skin. These lesions with LCV also showed notable epidermal change including basal layer vacuolar degeneration with mild dermoepidermal interface lymphocytic exocytosis. Six lesions with LCV displayed focal fibrin thrombi and capillary wall necrosis. Apoptotic keratinocytes were noted in 3 lesions with LCV. Subepidermal blister was observed in the skin lesion of an autopsied patient with LCV changes. Another lesion of a fatal case with LCV also contained features of acute neutrophilic eccrine hidradenitis. Focal small nerve twig inflammation was noted in a third autopsy case with LCV. Plasma cells were seen in 6 of 34 specimens (18%); and eosinophils were observed in 3 (9%). The subcutaneous fat contained a mild perivascular inflammation and one case revealed focal lobular neutrophilic inflammation. Immunohistologic (IH) staining using polyclonal rabbit anti-Rickettsia rickettsii demonstrated positive staining of the organisms in the affected endothelial cells in all 12 cases tested. The cutaneous histopathology of RMSF is caused by endothelial damage by the rickettsial organisms which elicit an initial lymphohistiocytic small vessel vasculitis with progression to LCV. The vasculitis in RMSF is, therefore, considered to be a form of septic vasculitis.

Primary cutaneous mucormycosis is a rare opportunistic fungal infection that is usually limited to the skin. We describe a primary cutaneous Rhizopus infection occurring at a site occluded by a sterile adhesive dressing in which the disease was viscerally disseminated at the time of diagnosis. Mucormycosis should be considered in all ecthyma-like lesions in immunocompromised patients. It may be rapidly diagnosed by examination of hematoxylin-eosin and PAS-stained sections of the eschar base and a culture of a leading edge tissue aspirate. We review 21 cases of primary cutaneous mucormycosis in children and compare them with the present case.

Eccrine spiradenoma (ES) rarely (less than 1%) occurs in infancy. These tumors differ from the conventional ES by the presence of superficial dermal nodules which display a less distinct two-cell pattern of immature adnexal epithelial cells and rarely ductule formation. These tumors may be mistaken for mesenchymal neoplasms involving the skin and subcutis of infants and young adults. Recognition of the histopathologic features and immunostains are required to make a definite diagnosis. We describe 2 cases of ES occurring in patients younger than one year. Detailed histopathologic and histochemical differential features of these tumors and mesenchymal neoplasms of the skin and subcutis commonly occurring in infants and young adults are discussed. The biologic behavior of infantile ES is benign, but complete excision is recommended to prevent recurrence. We speculate that these tumors may represent congenital hamartomatous growths.

Ultrastructural studies of Kaposi's sarcoma (KS) from skin biopsies of 24 patients (eight with acquired immunodeficiency syndrome (AIDS) and 16 without) were performed to delineate the nature of hyaline globules and vascular slits. These structures have been regarded as one of the important criteria for the recognition of KS under light microscopy. Histochemical and immunochemical studies were also performed to correlate with the electron microscopic (EM) observations. The most remarkable EM findings of KS were the intracytoplasmic lumen formation and erythrophagocytic activities of the neoplastic cells, particularly in the mature nodular, or neoplastic stage. The spindle-shaped or ovoid neoplastic cells frequently contained one to several intact and fragmented red blood cells. The intracellular and extravasated erythrocytes were often arranged in single files, giving these vascular slits an elongated appearance on longitudinal sections. The phagocytic activities of the neoplastic cells were demonstrated by the presence of membrane-bound lysosomes containing phagocytized erythrocytes and their partially digested forms (erythrophagosomes) adjacent to pinocytotic vesicles, prominent rough endoplasmic reticulum, and Golgi apparatus, as well as scattered, small, membrane-bound lysosomal granules, some of which were attached to the erythrophagosomes. The erythrophagosomes underwent various stages of disintegration. The partially digested red cells varied from 0.4 to 10 microns in diameter. The results of histochemical and immunochemical findings also strongly suggested that erythrophagosomes were most likely the hyaline globules (bodies) seen in light microscopy. The exact mechanism of erythrophagocytosis is uncertain. However, its consequences, erythrophagosomes, and intracytoplasmic lumen formation, particularly in the nodular or neoplastic stage in patients with and without AIDS, are among the important histologic features of KS.

Background and Design: During a trial of suramin for advanced solid tumors, a high rate of cutaneous adverse reactions was observed. We present a prospective study, describing the clinical, histopathologic, histochemical, and immunochemical findings of the cutaneous reactions observed in 60 patients treated with suramin. Results: Forty-nine (82%) of the 60 patients studied experienced at least one cutaneous reaction attributable to suramin therapy. Although morbilliform reactions predominated, a wide variety of eruptions was observed. Most reactions occurred within the first 24 hours of therapy and were selflimited despite continued drug infusion. Distinctive cutaneous findings included scaling erythematous papules (suramin keratoses) and a predilection of many eruptions for previously sun-exposed areas. Six patients experienced severe cutaneous reactions, but no patient permanently withdrew from therapy because of cutaneous toxic reactions. Common histopathologic findings included hyperkeratosis, para- keratosis, spongiosis, acanthosis, exocytosis, apoptosis, a perivascular lymphohistiocytic infiltrate, upper dermal edema, and increased dermal mucin. Staining with S100 antigen was markedly positive in several specimens. Only trace amounts of suramin were detected in skin samples tested with high-pressure liquid chromatography. Conclusions: The incidence of cutaneous toxic reactions from suramin greatly exceeds that seen with other medications. A wide spectrum of skin manifestations were observed, including suramin keratoses and UV recall, although serious reactions were infrequent. Cutaneous toxic reactions neither predicted nor correlated with other toxic reactions from suramin. Suramin may soon become more widely used; practitioners should be aware of the high incidence and wide spectrum of cutaneous toxic reactions to this drug. (Arch Dermatol. 1995;131:1147-1153)

Cutaneous mercury granulomas are rarely encountered. Clinically they pose difficulty in diagnosis when there is no clear history of penetrating injury by objects containing metallic mercury. Histologic, chemical, and scanning electron microscopic studies of such cutaneous lesions were performed on four cases from the Armed Forces Institute of Pathology files. Reported cases from the literature were reviewed. Metallic mercury in tissue sections appears as dark, opaque globules, usually spherical in shape and of varying sizes and numbers. A zone of collagen necrosis often surrounds the mercury globules. A granulomatous foreign body-giant cell reaction and a mixed inflammatory cellular infiltrate composed of neutrophils, lymphocytes, histiocytes, plasma cells, and occasional eosinophils are usually present. Epidermal and dermal necrosis, with or without ulceration or pseudoepitheliomatous hyperplasia, is also a common finding. The gold lysis test and energy-dispersive x-ray analysis confirmed the presence of metallic mercury in the tissue. Following cutaneous injury from mercury, systemic toxicity may develop and death may even occur. An approach to clinical management is discussed.

Squamous-cell carcinoma may arise in scars of chronic discoid lupus erythematosus. Although there have been 19 cases reported previously, detailed histopathologic features of this entity have not been recorded. We report a patient with extensive chronic discoid lupus erythematosus involving the scalp with subsequent development of multiple squamous-cell carcinomas. The tumors were locally aggressive with recurrences and invasion into the underlying skull and dura. The patient died of respiratory failure 4 1/2 years after initial surgical treatment. There was no clinical evidence of metastasis. Squamous carcinoma arising in discoid lupus erythematosus can be regarded as a low-grade carcinoma. Although about 20% of patients developed local recurrences and metastasis developed in about 30%, fatality occurred in only two patients (10.5%). Pertinent literature is reviewed, and the histopathologic findings, differential diagnosis, and biologic behavior of this tumor are discussed.

One hundred eight patients were studied who had anogenital lesions showing microscopic features as seen in bowenoid papulosis (BP), a recently described condition occurring most commonly in young adults. Patients typically show multiple papules, small nodules, or plaques that clinically mimic verrucae or nevocellular nevi. Although the lesions show microscopic cytologic atypia, a distinction from Bowen's disease, erythroplasia of Queyrat, and other forms of carcinoma in situ can usually be made on the basis of histologic and clinical criteria. The disorder responds to conservative treatment, although recurrences are not uncommon. Evolution of the lesions to invasive carcinoma was not observed. Mounting evidence links the development of BP to infection with human papilloma virus, but other viruses, as well as hormonal and immunologic factors, may also play a role.

Forty-six examples of carcinoma cuniculatum, a rare variant of squamous cell carcinoma of the skin, were studied by means of light and electron microscopy and immunoperoxidase techniques. The tumors usually presented as ulcerated, fungating, and polypoid masses with openings of sinus tracts onto the skin surface that exuded foul-smelling greasy material when pressure was applied. On microscopic examination the tumors were seen to be composed mainly of mature squamous keratinocytes with foci of cellular atypia. Electron microscopic studies revealed features of well-differentiated squamous cell carcinoma. The tumor may affect any cutaneous area of the body, and there is a predilection for the feet, particularly the soles. The cause must still be determined, but trauma, chronic irritation, and/or viral infection may play a role. The neoplasm is a low-grade carcinoma capable of local invasion, extension into bone, and rare metastasis to the regional lymph node. Although immunoperoxidase studies revealed no inclusions, infection by human papilloma virus (HPV) remains a possibility.

Eleven examples of a rare group of neoplasms composed of both epithelial and mesenchymal components are reported. Ten arose from the ovary and one arose separately in the para-ovarian region. The neoplasms are distinctive in that the stroma is more cellular than that of adenofibromas, but the epithelial component is not malignant, as in carcinosarcoma and mixed mesodermal tumors, and the stroma is not sarcomatous in the low grade varieties. The 11 cases were highly variable in the cellularity and atypism of the stromal cells. The term, adenosarcoma, for these tumors is not acceptable because some were too low a grade to be regarded as sarcomas, and reports of the uterine counterpart disclose that some contain heterologous elements. For that reason, a term that will embrace the full spectrum of changes in the stroma—benign through sarcomatous—is needed. We propose that they be regarded as variants of mixed mesodermal tumor so that both the benign neoplasms and low grade sarcomas can be accommodated under one designation. Of the 11 cases, five lowest grade examples were all confined to the ovary and did not recur after surgical excision, but some of these were borderline in malignancy and probably would have progressed if untreated. Two of the 3 intermediate grade neoplasms extended beyond the ovary but were arrested by surgical excision. The 3 highest grade neoplasms were overtly sarcomatous. One of these extended beyond the ovary but was arrested by combination chemotherapy. The para-ovarian adenosarcoma (also high grade) metastasized and proved fatal.

Epithelial atypia is rarely encountered in ovarian cystadenofibromas. Ten examples are reported with cytological features identical to serous tumors with low malignant potential. In two neoplasms the epithelium resembled an atypical endometrial hyperplasia, and one of these had squamous metaplasia. These two neoplasms probably qualify as endometrioid tumors of low malignant potential. None of the 10 patients had recurrence following excision of their neoplasm, and no similar patients have been encountered with neoplasms in more advanced stages. Even though aggressive behavior has not yet been established, the histologic features suggest a low degree of malignant potential and long-term follow-up of patients is warranted. Cystadenofibromas iwth epithelial atypia probably have less malignant potential than serous tumors of low malignant potential possessing the same epithelial characteristics because cystadenofibromas with atypia have less epithelial surface area and the epithelium is enveloped by connective tissue more than it is in serous tumors of low malignant potential.

A 21-year-old man presented with a 6-year history of episodic localized hyperhidrosis on the back of his hands. Results of the neurologic examination were normal. Profuse sweating of the affected skin was elicited by exercise, rasing core temperature, direct heat, and intradermal injections of cholinergic drugs. Examination of the affected skin by electron microscopy and light microscopy with special stains and enzyme methods revealed prominent hyperplasia of otherwise normal eccrine sweat glands and ducts and increased surrounding stromal hyaluronic acid.

A patient of Middle-Eastern descent developed Kaposi’s sarcoma of the skin and lymph nodes after renal transplantation while receiving medical immunosuppression, including the use of cyclosporine. The clinical presentation of this patient resembled that of the HTLV-III-associated Kaposi’s sarcoma. The tumors totally regressed seven weeks after cessation of immunotherapy. This case, along with other recently reported cases of Kaposi’s sarcoma in postrenal transplant patients receiving cyclosporine, illustrates a rare complication of current immunosuppressive therapy.

Paget's disease may occur at mammary and extramammary sites. Mammary Paget's disease typically involves the nipple and adjacent skin. Almost all such cases are associated with an underlying ductal carcinoma of the breast. A case of Paget's disease occurring at the site of an ectopic breast adjacent to a supernumerary nipple and associated with an underlying intraductal carcinoma is described. A search of the literature revealed no previous report of such cases. Detailed clinical history and histopathologic, histochemical, and follow-up information on this case are presented. The literature on mammary and extramammary Paget's disease is reviewed.

Fifty-seven examples of a rare eccrine sweat gland tumor (aggressive digital papillary adenoma and adenocarcinoma) were studied by means of light microscopy, electron microscopy, and immunoperoxidase techniques. The neoplasm occurred as a single, painless mass, almost exclusively on the fingers, toes, and adjacent skin of the palms and soles. Microscopic features were distinct from those of other eccrine sweat gland tumors and often led to the diagnosis of such metastatic carcinoma as that of the breast. The characteristic histologic features included tubuloalveolar and ductal structures with areas of papillary projections protruding into cystic lumina. The stroma varied from thin, fibrous septae to areas of dense, hyalinized collagen. Forty tumors were classified as adenoma (ADPA) and 17 as adenocarcinoma (ADPAca). Histologically, ADPAca was distinguished from ADPA by its poor glandular differentiation and by necrosis, cellular atypia and pleomorphism, invasion of soft tissue and bone, and invasion of blood vessels. Eighteen (50%) patients with ADPA and 8 (47.0%) who had ADPAca developed recurrent lesions (2 months to 9 years) after surgical removal of the tumor. Seven (41.2%) patients with ADPAca developed metastases, of which 5 involved the lung. Three patients died of metastases, 5 to 20 years after surgical treatment of the primary tumor. The histologic malignant features in ADPAca are indicative of potential for distant metastasis and fatality. The recognition of aggressive digital papillary adenoma and adenocarcinoma as a distinct clinicopathological eccrine sweat gland neoplasm is important because of the potential for aggressive local growth and distant metastasis.

Focal acantholytic dyskeratosis (FAD) is a distinctive histologic pattern characterized by suprabasilar clefts surrounding dermal papillae (villi), acantholytic and dyskeratotic cells at all levels of the epidermis, hyperkeratosis, and parakeratosis. The features of FAD are typically seen in Darier's disease, warty dyskeratoma, and transient acantholytic dermatosis; they are also present in a variety of cutaneous neoplastic and nonneoplastic lesions. FAD, however, has not been previously described in lesions of inflammatory dermatoses. We report a case of FAD occurring in lesions of pityriasis rubra pilaris (PRP). To the best of our knowledge, this is the first reported case of this kind. We also review the pertinent literature.

Cystadenofibromas are benign ovarian neoplasms containing both epithelial and stromal components. The epithelial component is usually of simple serous type resembling fallopian tube epithelium. Occasionally, tumors with unusual epithelial pattenrs are encountered. In this study, 16 cystadenofibromas with unusual epithelium are described. Twelve are examples of an endometrioid type, 3 of a clear cell (mesonephroid) type, and 1 of a mucinous-type epithelium. The stromal component in all tumors is identical to that of ordinary cystadenofibromas. One of the patients with a tumor containing endometrioid epithelium developed recurrence in the vagina after surgical removal of the ovarian tumor. The rest of the clinical features of these tumors are similar to those of ordinary cystadenofibromas with the exception that the median age is 10--20 years greater in the unusual-epithelium group.

Bowen's disease (BD) is generally regarded as a premalignant dermatosis.1-3If untreated, 3% to 5% of patients may develop invasive carcinoma, which is capable of metastasizing and may even cause death.3, 4Clinically, the lesions of BD present as a scaly, slightly elevated, erythematous plaque with surface fissures and foci of pigmentation. These lesions affect fair-skinned individuals more frequently and are equally distributed on the exposed and nonexposed parts of the body. Microscopically, BD is a form of carcinoma in situ characterized by full-thickness involvement of the epidermis and the pilosebaceous epithelium by atypical keratinocytes. The papillary dermis shows a dense, chronic, inflammatory infiltrate compound of lymphocytes, histiocytes, and plasma cells. Bowen's disease with invasive carcinoma (BD-CA) is not well recognized by clinicians because of its rarity and lack of specific clinical features. The lesion is often diagnosed as seborrheic keratosis, basal cell carcinoma, squamous cell carcinoma, BD