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Background Cutaneous cancer is the most common malignancy type, among which melanomas are considered the most aggressive and lethal. In Morocco, skin melanoma is the 25th most common cancer. To our knowledge, this is the first and largest Moroccan study specifically describing cutaneous melanoma. Materials and methods We obtained data for 100 patients diagnosed with cutaneous melanoma in the Department of Pathology of Hassan II University Hospital, Morocco. Clinical, histopathological, molecular, and follow-up data were recorded from pathology request forms and the patient's medical records. Results The mean age of our patients was 65 years old. Histologically, the most prevalent were the nodular (48%) and acro-lentiginous (38%) melanoma subtypes. A total of 66% of the patients had a Breslow thickness of >4 mm. The presence of ulceration was noted in 46% of cases. The average mitoses was 9/1 mm². A total of 44% of patients had metastatic melanoma at the time of diagnosis. The BRAF V600E mutation was found in six cases, and the C-KIT mutation in five cases. The five-year overall survival and metastasis-free survival were 85% and 15%, respectively. There was a significant correlation between Breslow thickness and Clark's level (p<0.001), histologic subtype (p=0.012), and presence of metastasis (p=0.002). There was a significant difference between the head and neck melanomas and those of the feet, particularly in the histological subtype and the presence of ulceration. BRAF V600E mutation was found in six cases of metastatic melanomas of the head and neck, of which three cases were positive for this mutation, as compared with the 23 cases of acral melanomas, which tested negative for the same mutation. Conclusion The results of our study showed that cutaneous melanomas were characterized by advanced age at diagnosis and late-stage diagnosis with a high Breslow index. The lower limbs were the most affected sites, especially in the plantar region. The acral lentiginous subtype was the most common. The presence of BRAF V600E mutation was associated with a better prognosis.
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Clear-cell sarcoma (CCS) was first described in 1968. It partly overlaps morphologically, immunohistochemically, and ultrastructurally with malignant melanoma (MM), hence its name "soft tissue melanoma." Nevertheless, there are sufficient cytogenetic differences between cutaneous melanoma and clear-cell sarcoma to consider clear-cell sarcoma as a separate entity. Clear-cell sarcoma of soft tissue is different from clear-cell sarcoma of the kidney. It is classified as a tumor of uncertain differentiation in the WHO 2020 classification of soft tissue tumors. It is an aggressive, rare malignant tumor that is involved in the deep soft tissues of the extremities and trunk. We report a case of primary clear-cell sarcoma of unusual presentation in a 31-year-old young man, mimicking metastatic melanoma. A 31-year-old man presented with a heel mass of 2.5 cm. Histologically, it was a dermal and hypodermal nodular proliferation of spindle cells of 23 mm with a grenz zone under the epidermis. There was no necrosis area or lymphovascular invasion. Surgical margins were free. There were no clinically suspicious lymph nodes. The tumor cells were stained for S100 protein, MELAN A, and HMB45, which led to an initial diagnosis of metastatic malignant melanoma. However, analysis by fluorescence in situ hybridization (FISH) found a rearrangement of the Ewing sarcoma region 1 (EWSR1) gene, which led to a diagnosis of primary clear cell sarcoma in the skin. This case highlights the importance of considering the diagnosis of a clear-cell sarcoma in front of any dermal lesions with morphological and immunohistochemical melanocytic features that do not have an in situ component and of atypical presentation, especially in young patients, hence the interest in performing fluorescence in situ hybridization for EWSR1, which remains the key to the diagnosis of cutaneous clear-cell sarcoma.