Cutaneous and Subcutaneous Prostate-Specific Membrane Antigen-Avid Lesions.

We report the case of a 62-year-old man with metastatic castration-resistant prostate cancer with subcutaneous involvement being treated with 177 Lu-prostate-specific membrane antigen (PSMA). Before treatment, he was diagnosed with 2 subcutaneous nodules in the chest wall and soft tissue edema in the pubic and inguinal regions showing PSMA avidity. Biopsy and immunohistochemistry assessment confirmed cutaneous metastases from prostate cancer. He received 3 cycles of 177 Lu-PSMA, resulting in a decline in PSA levels and resolution of symptoms. This case underscores the challenging diagnosis of cutaneous metastasis from prostate cancer, especially in atypical presentations. We also reviewed all causes of PSMA-avid lesions in the skin and subcutaneous tissues.