A Case of Perineal Skin Metastasis of Rectal Cancer after Laparoscopic Resection of the Rectum

Abstract

Cutaneous metastasis of colorectal cancer is rare. A 70-year-old woman underwent laparoscopic low anterior resection for a rectal adenocarcinoma in 2019.

Fifteen months later, she developed a mass in the right perineal region. The tumor marker CEA level had increased, and a pelvic CT scan detected an enhanced mass in the same region. A diagnosis of local recurrence was made. After 12 courses of chemotherapy with Panitumumab and mFOLFOX6, she had a clinical diagnosis of stable disease. Biopsy of the mass showed metastasis of rectal cancer, requiring a local excision. A pathological assessment revealed an adenocarcinoma-like colorectal cancer and immunohistochemical findings of a CK20, CDX2, and SATB2-positive and CK7-negative lesion. We made a final diagnosis of cutaneous metastasis of rectal cancer. She did not undergo adjuvant chemotherapy, and no recurrence was observed 17 months after excision.