Vulvar Metastasis From Colorectal Adenocarcinoma: A Report of a Rare Case and Review of Diagnostic and Therapeutic Approaches.

Vulvar metastasis from colorectal adenocarcinoma is extremely rare, with few cases reported in the literature. We present the case of a 49-year-old woman with a history of locally advanced, moderately to well-differentiated invasive adenocarcinoma of the distal rectum treated with neoadjuvant chemotherapy and abdominoperineal resection, including partial posterior vaginal wall resection. One year later, she developed a vulvar lesion associated with metrorrhagia. Pelvic magnetic resonance imaging showed an isolated vulvar lesion without pelvic recurrence. Histopathology and immunohistochemistry confirmed metastatic colorectal adenocarcinoma. A multidisciplinary decision led to systemic chemotherapy with irinotecan, leucovorin, and 5-fluorouracil plus bevacizumab. This case highlights the importance of integrating clinical evaluation, histopathology, immunohistochemistry, and imaging in diagnosing rare metastatic sites and emphasizes the role of multidisciplinary board decisions in guiding systemic therapy and optimizing patient management.