Cutaneous Metastasis As the First Sign of Small-Cell Cancer: an Unexpected Presentation in a Patient with Concurrent Prostate Cancer.

Cutaneous metastasis as the first sign of malignancy in a patient with no other clinical symptoms is extremely rare.1 We report the case of a patient presenting with a solitary groin metastasis as the initial manifestation of small-cell carcinoma (SCC) of likely pulmonary origin.2 Of note, the patient was concurrently receiving radiotherapy (RT) treatment near the groin for stage IIC (cT1cN0M0) high-risk prostate adenocarcinoma. Studies suggest that RT may stimulate previously circulating tumor cells to hone to the skin, which may explain the unusual site of the cutaneous metastasis.