Primary rectal adenocarcinoma with musculoskeletal metastasis as the only metastasis site: A case report with a short literature review.

Rectal carcinoma with metastasis to skeletal muscle is a rare occurrence. Since 1970, only 30 cases of skeletal muscle metastasis originating from colorectal adenocarcinomas have been documented, underscoring its exceptionally low incidence. Here, we present the case of a middle-aged man who was diagnosed with rectal adenocarcinoma 3 months ago. During examination, a subcutaneous mass was discovered in the left proximal buttock. Histological analysis of a biopsy confirmed that this mass was a metastatic lesion originating from the primary rectal adenocarcinoma.