Rectal adenocarcinoma presenting with thigh muscle metastasis as the only metastatic site. Issue 1 (22nd January 2019)

• Record Type: Journal Article
• Authors: Doroudinia, Abtin; Mehrian, Payam; Dorudinia, Atosa; Kaghazchi, Fatemeh
• Is Part Of: BMJ case reports. Volume 12:Issue 1(2019)
• Publication Date: 2019-01-22
• Subjects: colon cancer -- radiology; Medicine -- Case studies -- Periodicals; 610.5
• DOI: 10.1136/bcr-2018-226802
• Languages: English
• ISSNs: 1757-790X

Abstract

Abstract : Rectal carcinoma with metastasis to skeletal muscle is a rare finding. According to literature review, 17 cases of skeletal muscle metastasis from colorectal carcinoma have been documented where only six cases were rectal carcinomas. We discuss a case of a middle-aged man with a known history of high-grade mucinous adenocarcinoma of the rectum, status post abdominoperineal resection followed by adjuvant radiotherapy and chemotherapy. During the planned chemotherapy course, a right proximal thigh subcutaneous mass was incidentally found which on subsequent biopsy proved to be metastatic from rectal primary site. On subsequent 18F-FDG (Fluorodeoxyglucose) positron emission tomography (PET)/CT scan after completion of chemotherapy for the purpose of treatment response evaluation, only FDG-avid lesion was residual right proximal thigh metastatic mass without involvement of other common sites, such as liver and lung. In this case, the 18F-FDG-PET/CT scan was able to exclude additional metastatic sites and also evaluate the patient's treatment response.