Abdominal wall metastasis following open nephroureterectomy for upper tract urothelial carcinoma in a patient with Lynch syndrome.

A 74-year-old man developed the rare complication of an abdominal wall metastasis following open nephroureterectomy for upper tract urothelial carcinoma (UTUC). This occurred in the setting of synchronous contralateral ureteric and metachronous colorectal carcinomas. Immunohistochemistry demonstrated loss of the mutS homolog 6 (MSH6) mismatch repair (MMR) protein in the metastatic abdominal wall and colonic lesions, which in conjunction with meeting the Amsterdam II criteria, is strongly suggestive of Lynch syndrome (LS). Surgical resection of the recurrence was performed with clear margins and neither recurrence nor spread during short-term follow-up.