Search

Vitiligo is a chronic cutaneous disease characterized by the loss of melanocytes and consequent depigmentation of the skin, affecting approximately 0.5 to 2% of the global population. This complex dermatological condition has been the subject of extensive study in recent decades, aiming to understand its causes, pathophysiological mechanisms, and the development of effective therapeutic approaches. Evidence suggests that vitiligo results from a multifactorial interaction between genetic, autoimmune, environmental, and neuroendocrine factors. Immunological mechanisms, including oxidative stress and the autoimmune response targeted against melanocytes, play a crucial role in the disease's pathogenesis. Accurate diagnosis and effective management of vitiligo are essential to improve patients' quality of life. A variety of therapeutic options are available, including phototherapy, topical treatments, melanocyte transplantation surgery, and immunomodulatory therapies. This review aims to provide a comprehensive overview of vitiligo, addressing its clinical characteristics, pathophysiology, and treatment options based on the evidence available in the scientific literature. [ABSTRACT FROM AUTHOR]

Background: Melanoma is a malignant neoplasm that arises from melanocytes and malanoblasts. It is also more frequently reported in dogs than in other species. They may arise from melanocytes in the skin, on the surfaces of the mucous membranes, and eyes. The aim of this study was to describe the epidemiological aspects, risk factors and clinicopathological findings of melanoma in dogs in the backlands, northeastern Brazil. Materials, Methods & Results: A retrospective study was carried out in all biopsy samples and necropsy examinations of dogs, from January 2003 to December 2021, at the Animal Pathology Laboratory of the Federal University of Campina Grande, Patos, Paraiba, northeastern Brazil. Epidemiological data, clinical signs, and gross lesions were reviewed from the diagnostic laboratory reports. Samples of the skin, lymph nodes, central nervous system and organs of the thoracic and abdominal cavities were fixed in 10% buffered formalin, processed routinely for histopathology, embedded in paraffin wax, cut into 4 µm sections, and stained with hematoxylin and eosin (HE). Histological sections were also submitted to immunohistochemistry with the primary antibody anti-Melan A. Of the 4717 records found, 1158 (24.5%) were diagnosed with neoplasms, of which 48 (4.14%) cases were of melanoma. Of this total, 28 (58.3%) dogs were elderly, 19 (39.6%) were adults, and 1 (2.1%) was young. Mixed breed animals were the most affected (42.6%), followed by the pinscher breed (19.1%). According to the anatomical region, the most affected site was the skin (38/53=71.7%), followed by the oral cavity (12/53=22.65%) and the eyes (3/53=5.7%). Grossly, the skin lesions were characterized by exophytic and usually blackened, sometimes irregular and firm, nodules. At cut, they had a smooth, compact and blackened surface. Lesions in the oral cavity were characterized by blackened, irregular and infiltrating nodules or masses. The ocular lesions were always unilateral and were characterized by an enlarged and diffusely blackened eyeball, with areas of ulceration and subversion of tissue architecture. In 5 animals there was more than one anatomical site affected, totaling 53 lesions. In 9 (17%) cases, metastases were identified, 8 in regional lymph nodes and 1 in the lung. Histopathology showed a densely non-encapsulated, poorly delimited, expansive and infiltrative neoplasm, composed of neoplastic cells arranged in islands or nests and supported by fibrovascular stroma, containing a variable amount of brownish pigment (melanin). Immunohistochemistry showed strong immunostaining of the neoplastic cells in brown by the anti-Melan A antibody. Discussion: The diagnosis of melanoma was established based on epidemiological, clinical, anatomopathological, and immunohistochemical findings. Gender is not a predisposing factor, and although there was no statistically significant relationship, males were more affected. Senescence is a conditioning risk factor. Elderly animals were more affected (P < 0.0001) than adult ones, with OR = 4.38; and young ones (P = 0.0051), with OR = 12.65. Some breeds, especially those with marked skin pigmentation, were more affected, however the most affected ones in this survey were pinscher and poodle. Cutaneous melanoma accounted for almost 72% of cases, contesting recent studies where oral cavity melanoma was more frequent. Therefore, it is believed that the climatic conditions of the backlands sub-region, in northeastern Brazil, associated with the individual characteristics of the dogs, are involved in the development of these neoplasms, since the climate is predominantly dry, with high temperatures throughout the year, with maximums that can reach 40ºC, favoring the exposure to high incidence of ultraviolet radiatio [ABSTRACT FROM AUTHOR]

Introduction: Melanocytic lesions may present with several histologic features that make them impossible to classify in a dichotomous way, as benign or malignant. Such lesions, designated as melanocytic proliferations of uncertain malignant potential, frequently show borderline features between benign nevus and malignant melanoma, reflecting their undetermined biological potential. Methods: In order to characterize melanocytic proliferations of uncertain malignant potential diagnosed at our center between 2007 and 2017, histopathological reports of melanocytic lesions classified, in this period, as either dysplastic or malignant were analyzed. Results: Twenty-three lesions (4.3%) with borderline histopathological features or uncertain malignant potential were identified. The mean patient age was 34.8 years. Sixteen lesions (69.6%) were observed by a second pathologist, with an inter-observer disagreement on 25%. The most frequently performed treatment was wide excision, with large variability regarding the surgical margins. A sentinel lymph node biopsy was performed in two patients, both being negative. The median follow-up time was 22 months, and there was no recurrence of any treated lesion. Conclussion: The controversy of this subject extends from the nature and classification of these lesions to their treatment. With this study we were able to verify the variability regarding their histologic characterization, as well as their treatment. However, the inexistence of recurrences and deaths attributable to the disease corroborates their frequently benign character and excellent prognosis. [ABSTRACT FROM AUTHOR]

Background: Ocular melanocytosis was originally described as pigmentary glaucoma and reported in seven dogs of the Cairn Terrier breed. Subsequently, the occurrence of this condition was reported in other breeds of dogs among them a Shih Tzu, recently described. With progression, black pigment spots in the sclera and episclera cover the ciliary cleft. Pigment particles can often be seen suspended in the aqueous and, as they sediment, cover the ventral drainage angle, causing secondary glaucoma. The aim of this study was to describe the clinical and sonographic findings of a Shih Tzu dog with melanocytosis and unilateral secondary glaucoma. Case: A 8-year-old, male, Shih Tzu dog, with a history of progressive darkening of the sclera for 5 years, was referred to the ophthalmological service. The patient underwent routine ophthalmic examination. Slit lamp biomicroscopy revealed anisocoria. In the right eye, diffuse pigmentation of the sclera was observed in almost the entire perilimbal region, and in the iris signs of advanced atrophy with tissue loss between 9 h and 12 h. Nevertheless, zonular ligaments could be observed in this region, as well as a large amount of pigment deposits in the ventral region of the ciliary cleft. Applanation tonometry showed intraocular pressure (IOP) of 14 mmHg. Fundoscopic examination did not reveal abnormal pigmentation, but attenuation of the retinal vessels and in the optic disc was observed. In the left eye, no change was observed to demonstrate the bilaterality of the disease. One month later, the patient returned to the ophthalmology service complaining of an increase in the size of the right eye. Ophthalmic examination revealed moderate buftalmia in the right eye, IOP of 30 mmHg and increased ocular melanosis. Treatment was instituted to control intraocular pressure. Fifteen days after the start of treatment, the IOP decreased to 18 mmHg and it was found that the ophthalmic signs had improved, with a decrease in ocular discomfort. Ultrasound examination showed an increase in the anteroposterior axis and expansion of the anterior chamber, with scattered hyperechogenic spots in the periphery. Ultrasound biomicroscopy (UBM) was performed, in which the presence of obstruction in the ciliary fissure and the presence of punctate echoes between the ciliary fissure and the iris were observed. Four months later, the ophthalmic signs were stable, as well as the IOP (20 mmHg). Currently, the animal is visual in both eyes and with a stable condition in the progression of the disease. Discussion: This condition also known as melanocytosis, pigmentary glaucoma or abnormal pigment deposition, involves the gradual accumulation of pigment-laden cells mainly, melanocytes but also melanophages, in the anterior segment structures including the iris and ciliary body. It is seen in dogs of the Cairn Terriers breed as a hereditary defect, but has been reported in other breeds. Recently the condition was reported in a Shih Tzu, however differently from our work where the condition was unilateral and with a controllable glaucoma. The disorder initially manifests clinically with a progressive bilateral dark peripheral thickening of the iris base, followed by scleral/episcleral plaques of pigment adjacent to the limbus. Signs increase slowly, with pigment clusters in the aqueous and pigmentation in the ventral iridocorneal angle and peripheral endothelium, symptoms are usually bilateral, although not always symmetrical. This is the 1st case of a Shih Tzu with melanocytosis and controlled secondary glaucoma, unilateral, reported in the literature. This is a disease that should be considered as a differential diagnosis of uveal melanomas and melanocytomas. [ABSTRACT FROM AUTHOR]

Background: Melanocytic neoplasms are skin tumors that often occur in dogs. However, melanocytoma-acanthoma, also called melanoacanthoma, is a benign melanocytic neoplasm rarely reported in this species, which has been described only three times in the veterinary literature. Briefly, this tumor is characterized by a single, painless, darkly pigmented and firm cutaneous papule or nodule. Histologically, it is composed of mixed populations of well-differentiated melanocytes and keratinocytes, unlike traditional melanocytic tumors (melanoma and melanocytoma). These cells are arranged in lobules surrounded by collagenous stroma. Melanocytes are large epithelioid cells containing varying amounts of melanin. Kera- tinocytes form anastomosing trabeculae with peripheral palisading, and small cysts containing amorphous or laminated keratin. The definitive diagnosis of melanocytoma-acanthoma is based on histopathological findings. This report describes a case of melanocytoma-acanthoma in a dog in Brazil. Case: A 9-year-old female miniature Schnauzer dog was examined at the Veterinary Hospital of the Federal University of Santa Maria, where a single, firm, pigmented papule was found in the auricle. The lesion had started 15 days earlier. Hematological tests and serum biochemistry profile were normal. An excisional biopsy of the papule was surgically removed and subjected to histopathological examination. The tissue was fixed in 10% neutral buffered formalin, processed routinely and embedded in paraffin wax. Sections were stained with hematoxylin and eosin (HE). A histopathological examination revealed a nonencapsulated, well-defined, extensive, densely cellular proliferation located in dermis. This proliferation was composed of lobules and nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes, surrounded by thin bundles of fibrous stroma. A diagnosis of melanocytoma-acanthoma was established based on these histological features. Discussion: The first description of melanocytoma-acanthoma in humans was as melano-epithelioma, classified into subtypes I and II. Both subtypes are benign neoplasms composed of well-differentiated melanocytes and keratinocytes, which are distinguished from one another based on the amount and distribution of melanocytes. Type I melano-epithelioma is characterized by proliferative lobules of melanocytes and keratinocytes, including melanocytes scattered diffusely among keratinocytes. Type II melano-epithelioma involves only the proliferation of keratinocytes, while melanocytes are limited to the basal layer of keratinocyte lobules. To clarify this condition, some authors use the term "melanoacanthoma" to indicate the above-described type I melano-epithelioma, and seborrheic keratosis to indicate type II melano-epithelioma. However, other authors use the term melanoacanthoma to denote the two conditions (types I and II melano-epithelioma). On the other hand, veterinary medicine does not recognize subtypes, instead using the term melanocytoma-acanthoma, and more recently, melanoacanthoma, to denote this cutaneous neoplasm. Melanocytoma-acanthoma in dogs was first reported in Spain, and involved a 2-year-old German shepherd dog. Later, two other cases were described in adult mixed-breed dogs, one in South Korea and the other in Libya. This is the first report of melanocytoma-acanthoma in a dog in Brazil. The gross and histopathological appearance of this case matches that described in the previous cases (a single, well-defined, pigmented cutaneous papule or nodule). Histologically, the differential diagnosis for melanocytoma-acanthoma includes melanoma, melanocytoma, trichoepithelioma, and sebaceous epithelioma. [ABSTRACT FROM AUTHOR]

Introduction: The appearance of pigmented lesions in scars of malignant melanoma is a finding that worries dermatologists/dermatopathologists, because they are faced with the possibility of persistence/recurrence of malignant melanoma. Case reports: We present three cases of patients with melanocytic pigmentation in scars of malignant melanoma and discuss the clinical and histological aspects of these. In all cases, we observed macules similar to lentigo spots, but histologically we observed three different patterns: lentiginous epidermal hyperplasia, lentiginous hyperplasia of melanocytes and malignant melanoma in situ. Discussion: There are three types of pigmentation, which may arise in the scar of malignant melanoma: lentigo type lesions, pigmented streaks and diffuse pigmentation. Histologically, three patterns of melanocytic pigmentation in scars of malignant melanoma, are described: lentiginous epidermal hyperplasia, lentiginous hyperplasia of melanocytes and persistence/ recurrence of malignant melanoma. The scar appears to be responsible for pigmentation by a process of induction acting on epidermal melanocytes. [ABSTRACT FROM AUTHOR]

The word vitiligo derives from the Greek Vitellius, which means "white spots of a calf." Vitiligo is translated by an acquired loss of pigmentation, characterized histologically by the absence of epidermal melanocytes. This is probably an autoimmune disease associated with the formation of anti- melanocyte antibodies, but the pathogenesis is not fully understood. Studies suggest that there is some mechanism in nature polygenic. A lot of factors have been associated with the pathogenesis of the disease including genetic, autoimmune and environmental factors heritage, and family history is positive in at least 30% of cases. One aspect of this pathology should not be overlooked is the psychosocial and social discrimination imposed on such patients. Os most common sites of skin lesions are peri-anorectal, face, genitals, mucous membranes, ex-tensor surfaces, hands and feet. The diagnosis of vitiligo is essentially clinical. Can be confirmed demonstrating a high level of uroporphyrin in the urine of 24 hours has caste-mance-reddish ("port wine urine"). There are several treatment options available, most directed to restore the skin pigment all of which have advantages and disadvantages. Inserts in the process topical treatment with corticosteroids and calcipotriene, as well as alternative therapy by physical agents (such as with ultraviolet B rays and ultraviolet A light, excimer laser), psoralens and systemic corticosteroids monkeys with surgery and grafting, in addition to the transplantation melanocytes. All the treatment options have limited success. There are no ways to prevent vitiligo. The implications of treatment are generally very rewarding, which contributes strongly to the significant improvement in self-esteem and quality of life of the patient in question. [ABSTRACT FROM AUTHOR]

Angiomatoid Spitz nevus is a rare tumor that combines the classic aspects of Spitz nevus with a prominent vascular component. Clinically, it presents as a pink or brownish papule, usually solitary, in the extremities of young adults. On histology, it is characterized by a proliferation of epithelioid or spindle cell melanocytes embedded in a fibrous stroma, where a dense proliferation of small vessels is evident. The differential diagnosis with malignant melanoma can be difficult, particularly with the desmoplastic variant or with those with marked regression. Its behavior is benign, as suggested by the absence of local recurrences or distant metastases during long-term follow-up. [ABSTRACT FROM AUTHOR]

Skin color is determined by the presence and distribution of a dark pigment called melanin, the pigment being produced by cells called melanocytes. When there are disorders in the melanogenic process, may cause hyperpigmentation, being the most frequent melasma which is characterized by patches ranging from light brown to dark brown, where the main causes are exposure to sunlight or other sources of ultraviolet radiation, genetic influences, pregnancy, contraceptive use or hormone replacement therapy. Today in the market, there are several depigmenting substances, but the bleaching agent hydroquinone is the most commonly used for treating hyperpigmentation such as melasma. Its mechanism is based on the interference of melanin production, inhibiting the activity of tyrosinase, preventing the transformation of tyrosine into DOPA or diidroxifenilalamina, which striker is melanin. Preparations containing hydroquinone are susceptible to oxidation, thus, should be incorporated into the formulation the association of EDTA as the chelating agent sodium bisulfite, sodium metabisulfite, sodium dithionite to the most commonly used for this purpose. Before that, depigmenting agent hydroquinone is more often used in cases of hipercromies to be effective and be affordable. The aim of this study was to describe the origin of melasma, its causes and characteristics, as well as the effectiveness of hydroquinone as a bleaching agent. [ABSTRACT FROM AUTHOR]

Introduction: Dermoscopy is an in vivo, non-invasive technique that is widely used as a complementary method for the study of pigmented skin lesions and enables the early diagnosis of cutaneous melanoma. The purpose of the present study is to evaluate the diagnostic accuracy of dermoscopy and to extend the dermoscopy-histopatholoy correlations. Methods: Retrospective study using the database of the Dermoscopy and Pigmented Lesions Clinic and the database of the Histology of the Dermatology Department of CHUC. Each melanocytic lesion was evaluated according to multiple dermoscopic and histopathological parameters. The agreement between diagnoses and between the evaluated parameters was determined. Results: The malignant/benign ratio was 1:9.2. The agreement between the dermoscopic and histologic diagnoses was fair. The agreement for melanoma was excellent and dermoscopy showed 92.9% sensitivity and 96.9% specificity for this diagnosis. There was agreement between a reticular pattern and the presence of bridging of rete ridges and cytological atypia; globular pattern and the presence of nests; atypical network and presence of fibrosis and cytological atypia; blotches and pigmented parakeratosis; blue-whitish veil and fibrosis. Conclusion: In spite of some limitations and unexpected findings, many of the results of the present study are concordant with the literature, showing a high sensitivity and specificity of dermoscopy in the diagnosis of melanoma, which results in improvement in early diagnosis without increasing the total number of excisions of pigmented lesions. [ABSTRACT FROM AUTHOR]