Malignant Melanoma in the Groin Masquerading as a Vascular Tumour: A Rare Cytodiagnosis

Malignant melanoma (MM) is an aggressive cutaneous neoplasm tending to metastasise anywhere within the body. It frequently metastasises to the draining lymph nodes. A distinct presentation of MM occurs when metastatic lesions appear in the regional lymph nodes, while the primary tumour remains clinically undetected. Fine needle aspiration cytology (FNAC) is highly sensitive, rapid, and cost-effective. The utility of the FNAC procedure is well established in the patient's diagnostic workup. However, the Indian data on the cytodiagnosis and cytomorphology of metastatic MM are very scarce. We submit a clinicopathological profile of a rare case in a 68-year-old male, where FNAC from an inguinal mass led to the diagnosis of metastatic MM, which mimicked clinically as a vascular tumour. The present case highlights MM's unusual clinical presentation and cytomorphological details through FNAC.