The dermis contained nodules and infiltrative strands of pleiomorphic anaplastic tumor cells, with approximately 1 to 2 mitoses per high-power field. Rare rudimentary partially formed glandular structures were noted. Staining was negative for carcinoembryonic antigen, leukocyte common antigen, and S100 protein within the tumor, while PSA and prostate-specific acid phosphatase stained focal tumor cell membranes.
Skin metastases occur in up to 9% of visceral malignancies,1,2 most often from breast, lung, and colon carcinomas.3 Although prostatic carcinoma is the most common cancer in men, its usual sites of metastasis are bones, lungs, liver, and adrenal glands.4 Skin metastases from prostate cancer are extremely rare and account for fewer than 1% of all cancers metastatic to the skin.1,4
Infiltrated Groin Plaque in an 81-Year-Old Man. Arch Dermatol. 2001;137(4):495-500. doi: