# A Rare Presentation of Cystic Metastatic Melanoma in the Upper Chest

## TL;DR

A rare case of metastatic melanoma presented as a cystic nodule on the chest, highlighting the need for thorough evaluation of unusual lesions.

## Contribution

This case report highlights the rare cystic presentation of metastatic melanoma without a known primary tumor.

## Key findings

- A 57-year-old male presented with a smooth cystic nodule that was diagnosed as invasive malignant melanoma.
- Histopathology and immunohistochemistry confirmed melanoma despite the lesion's benign appearance.
- The case emphasizes the importance of evaluating asymptomatic lesions for metastatic melanoma.

## Abstract

A 57-year-old male was evaluated for a smooth cystic nodule on his left upper chest that appeared clinically to be a cyst, yet histopathology and confirmatory immunohistochemistry revealed invasive malignant melanoma. Histopathologic evaluation and immunohistochemical staining (i.e., SOX-10 and MART-1) are useful diagnostic tools for invasive malignant melanoma that, albeit rare, can present without known or cutaneous primary. This case illustrates the variability with which metastatic melanoma can present, calling attention to the importance of careful evaluation of benign-appearing and asymptomatic lesions.