Abstract

Prostate cancer is the most common malignancy in men worldwide after non-melanoma skin cancer. It is well known to metastasize, with 3-17% of patients having metastatic disease on presentation. Of metastatic cases, the bone is most often involved (84%), followed by distant lymph nodes (10.6%) and the liver (10.2%). Much more rarely (0.06-0.36% of all cases), prostate cancer can metastasize to the skin, most commonly the lower abdomen. We present the case of an 88-year-old male with a known past medical history of prostate and esophageal carcinomas who presented with an 8-week history of clustered friable violaceous nodules and papules in the left and right superior inguinal folds and mons pubis. The lesions were reported to bleed but were nontender. A punch biopsy was taken, and examination of the lesion demonstrated histopathologic features diagnostic of a metastatic adenocarcinoma, which was confirmed as prostatic adenocarcinoma by immunohistochemistry (positive for NKX 3.1, cytokeratin AE1/AE3, and prostate-specific antigen; negative for SOX-10, p40, CDX2, TTF-1, CK7, and CK20). The patient was then referred to oncology and lost to follow-up. We present this case to add awareness and to add to the sparse medical literature of cutaneous metastases of prostatic carcinoma.