# Incidental Discovery of Melanoma Metastasis in the Thenar Compartment: A Case Report

## TL;DR

A patient with a hand tumor was found to have a melanoma metastasis, despite the tumor's non-malignant appearance and unusual location.

## Contribution

This case report highlights an unexpected melanoma metastasis in the thenar compartment, emphasizing the importance of thorough histopathological analysis.

## Key findings

- A 2 cm tumor in the thenar compartment was found to be a metastasis from melanoma.
- A small melanoma lesion was identified on the patient's scalp through biopsy.
- The tumor's benign clinical appearance contrasted with its malignant histopathological findings.

## Abstract

This report details the evaluation and management of a patient who presented with a tumor located in the thenar compartment of the left hand. The mass measured approximately 2 cm along its longest axis and exhibited no clinical signs of malignancy. However, imaging results and histopathological analysis of the biopsy indicated a malignant process, leading to the decision for tumor resection. The unique aspect of this case is the histopathological analysis of the surgical specimen, which revealed the tumor as a metastasis from a melanoma. This diagnosis was unexpected due to the location and clinical characteristics of the tumor. Biopsies of several dermatological lesions in the patient revealed a small lesion on the scalp, which was diagnosed as a localized melanoma.