Lower Extremity Desmoplastic Malignant Melanoma in Egypt

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Desmoplastic melanoma (DM) is a rare, non-pigmented subtype of melanoma.
• Its spindle cell morphology and lack of pigment present diagnostic challenges, mimicking benign tumors, other malignancies, and inflammatory conditions.
• Accurate diagnosis is crucial for appropriate patient management and treatment.

Purpose of the Study:

• To report a case of desmoplastic melanoma presenting as multiple nodular lesions.
• To emphasize the diagnostic difficulties encountered in differentiating DM from other skin conditions.
• To highlight the definitive role of histopathological examination in diagnosing DM.

Main Methods:

• Clinical presentation of a patient with multiple lower extremity nodules after electrocautery.
• Differential clinical diagnoses considered: Kaposi sarcoma, hypertrophic lichen, extensive verruca vulgaris.
• Histopathological examination of lesional biopsies.

Main Results:

• Histopathology revealed spindle-shaped cells.
• Immunohistochemical staining was positive for Melan-A and S100.
• These findings confirmed the diagnosis of desmoplastic melanoma.

Conclusions:

• Desmoplastic melanoma can present atypically, posing a diagnostic challenge.
• Clinical suspicion and thorough histopathological evaluation, including immunohistochemistry, are essential for accurate diagnosis.
• Prompt diagnosis of DM is critical for effective therapeutic strategies.