European Journal of Biomedical and Pharmaceutical Sciences

A RARE CASE OF AMELANOTIC MELANOMA OF THE LEFT FOOT WITH LEFT INGUINAL LYMPH NODE METASTASIS

Bhumika Patel*, Jagadale Kunda, N. S. Mani, Mahendra Chaudhari, M.D., Sai Sankeerth Madakasira, M.D. and Anish Jagadale

ABSTRACT

Introduction: Presence of melanin pigment allows for diagnosis of malignant melanoma. However, amelanotic melanomas make up 2 to 20% of all melanomas which contain little or no pigment. So, use of Immunohistochemistry (IHC) in diagnosis of amelanotic melanoma is essential. Case presentation: A 31-year-old female patient presented with a left foot ulcer since 10 years and left inguinal swelling since 6 months. Fine Needle Aspiration Cytology of Left inguinal lymph node was suspicious for malignancy. No pigments were found in left foot ulcer biopsy and left inguinal lymph node(s). A pre-emptive diagnosis based on biopsy was a poorly differential malignancy with inguinal metastatic deposits. Upon performing Immunohistochemistry with one melanocytic marker diagnosis was established as amelanotic melanoma. Discussion: Amelanotic melanomas have no cytoplasmic melanin pigment. They have one or more secondary amelanotic lesions. There is no distinctive morphological look. It is hence advised to rule out amelanotic melanoma in every poorly differentiated tumour using Immunohistochemistry markers like Melan A and HMB45. The most sensitive marker, S100 is 95–100% positive in melanomas. Conclusion: When a diagnosis of poorly differentiated malignancy is obtained, performing melanotic markers in the immunohistochemistry panel must be considered to confirm or rule out amelanotic melanoma.

Keywords: Amelanotic Melanoma, Histopathology, Immunohistochemistry, Melanoma, Melanotic markers.