Challenges in Diagnosis of Melanoma from the Perspective of a Pathologist

Introduction: Melanoma is an aggressive melanocytic neoplasm with a continuously increasing incidence worldwide. Vast majority of melanoma arises from skin whereas a small subset of melanoma can arise as a primary malignancy of mucosal membranes. Gastrointestinal (GI) melanoma is usually metastatic in origin whereas primary GI melanomas are extremely rare. Anorectal Melanoma comprises of 1/% of all malignant neoplasms of this area. About 70% of these lesions are pigmented whereas 30% of them are amelanotic. Upto 25% of the patients with melanoma develops recurrent disease locally or in regional lymph nodes. Materials And Methods: This is a prospective study conducted in a tertiary care hospital comprising of six cases of Melanoma. We studied the cases according to their age, sex, clinical presentation, site, radiological findings, histopathological findings, immunohistochemical findings and treatment provided. Results: This study comprises of six cases of Melanoma among which five cases are primary one case is recurrent. Among the five primary cases, four cases have GI origin (sigmoid colon, rectum, anal canal) one case originated from skin involving left foot. There is a single case of recurrent MM involving right inguinal lymph nodes with a history of primary MM in the right lower limb. The patients belong to the age group of 6th to 8th decade with male preponderance. Histopathological examination of formalin fixed paraffin tissue sections was done followed by Hematoxylin & Eosin and Immunohistochemical staining which confirmed the diagnosis of Melanoma. Conclusion: Melanoma is an aggressive melanocytic neoplasm that carries a poor prognosis. It commonly involves skin. Its occurrence in GI tract is rare in which primary lesions are exceedingly unusual. Diagnosis and Treatment require multidisciplinary team approach with surgery remaining as a cornerstone of treatment.