Melanoma desmoplásico mixto / Mixed desmoplastic melanoma

El melanoma desmoplásico es una variedad infrecuente de melanoma que se distingue por su presentación clínico-patológica y su comportamiento biológico. El diagnóstico temprano es un desafío por su presentación clínica variable, con predominio del componente dérmico y la frecuente ausencia de pigmento. En la histología se lo divide en puro y mixto y esta clasificación tiene importantes implicancias pronósticas. El espesor de Breslow promedio al momento del diagnóstico es mayor que en otras variantes de melanoma, sin embargo, la tendencia a generar metástasis ganglionares es menor.

Desmoplastic melanoma is a rare presentation of melanoma with a different clinical behavior compared to other histological variants. Its diagnosis in early stages is a challenge due to its variable clinical presentation, with a predominant dermal component and the frequent absence of pigment. Its histology is divided into pure and mixed type, and this classification has important prognostic implications. The average Breslow thickness at diagnosis is higher than in other melanoma variants. However, the tendency to lymph node metastasis is low.

Desmoplastic melanoma of the oral cavity: diagnostic pitfalls and clinical characteristics

OBJECTIVES: Desmoplastic melanoma of the oral cavity is an extremely rare condition that is often confused on initial diagnosis with non-melanotic benign lesion or spindle cell tumors. The purpose of this article was to raise awareness of the disease using a literature review. MATERIALS AND METHODS: We analyzed 19 desmoplastic melanoma cases reported in the literature and added our experience. Data on clinical, histopathology, treatment, and survival were retrieved and analyzed. Survival analysis was by the Kaplan-Meier method. RESULTS: Initial clinical and histopathological features were indistinctive, and a definite diagnosis of desmoplastic melanoma at initial assessment was possible in only 23.5% of cases. Among tests, immunohistochemical studies for S-100 and vimentin were all positive. The 5-year disease-free survival rate for oral desmoplastic melanoma was 0%, and the 5-year overall survival rate was 55.0%. CONCLUSION: Oral desmoplastic melanoma has a high percentage of initial misdiagnosis and propensity for local recurrence. Thus, careful initial diagnosis and adequate surgery may result in improved overall survival.

A Case of Desmoplastic Melanoma / 대한피부과학회지

No abstract available.

A Case of Desmoplastic Melanoma / 대한피부과학회지

Desmoplastic melanoma is a rare variant of the spindle cell melanoma that first was recognized and described in 1971 as an invasive fibrosarcoma-like tumor that exhibits an abundant collagenous stroma. These tumors usually arise in sun-damaged skin of the head and neck in older persons, in association with lentigo maligna or de novo. The clinical presentation is often not characteristic, and they may clinically simulate other tumors of the skin. Hence they are often diagnosed late. Histologically, desmoplastic melanoma appears as a nodule of fibrous tissue containing hyperchromatic pleomorphic spindle cells that either are scattered singly, lie in fascicles, or aggregate in nests, and collagenous tissue replacing the reticular dermis. Immunohistochemistry is usually quite helpful as the tumors are almost always immunoreactive with S-100 protein and negative for HMB-45. We report a case of desmoplastic melanoma in a 67-year old male who had a walnut sized tumor upon large indurated plaque on the left thigh. A biopsy specimen of the tumor showed that fascicles of spindle cells are interspersed throughout collagenous tissue and most tumor cells are immunoreactive with S-100 protein. To our knowledge, this is the first case report in Korea.