title: A case of metastatic rectal squamous cell carcinoma initially diagnosed as lung cancer.
abstract: Squamous cell carcinoma (SCC) of the rectum is extremely rare with a reported incidence of only 0.025-0.1% of all colorectal tumors. The patient was a 68-year-old man who presented with fatigue, dry cough, shortness of breath, and unintentional weight loss. A chest CT revealed a left suprahilar mass suspected to be lung cancer and an initial diagnosis of primary lung cancer was made. However, fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) exam revealed an intensely hypermetabolic rectal mass which turned out to be rectal squamous cell carcinoma. This is the first report that shows FDG-PET/CT images of rectal squamous cell carcinoma metastasis to the skin, muscle, bone, and lung. Use of PET/CT in the initial diagnosis of non-resectable rectal cancers may avoid unnecessary surgery.
authors.affiliation: Department of Radiology, San Francisco VA Medical Center, San Francisco, California, USA.
authors.forename: Aung Zaw
authors.initials: AZ
authors.lastname: Win
authors.affiliation: Department of Radiology, University California San Francisco (UCSF), San Francisco, California, USA.
authors.forename: Carina Mari
authors.initials: CM
authors.lastname: Aparici
keywords: Bone; fluorodeoxyglucose positron emission tomography and computed tomography; metastasis; muscle; rectal squamous cell carcinoma; skin nodule