2022 Volume 64 Issue 3 Pages 262-269
A 49-year-old man underwent a screening fluorodeoxyglucose positron emission tomography (FDG-PET), which revealed increased F-18 accumulation in the rectum. A fecal occult blood test was also positive. A subsequent colonoscopy revealed diffuse granular lesions in the lower rectum. Histopathological examination showed nonspecific inflammatory findings, such as inflammatory cell infiltration and lymphocyte aggregation. As the patient was asymptomatic, he was observed without any medications. Five months later, he developed symptoms of loose stool 4-5 times a day, abdominal pain, and tenesmus.
The second colonoscopy showed diffuse granular lesions in the rectum and rough-surfaced mucosa with loss of vascularity from the rectum to the splenic flexure, as well as a cluster of micro-erosions around the appendiceal orifice. In the second histopathological examination, a decreased number of glandular ducts and goblet cells and diffuse infiltration of various inflammatory cells were observed. Based on these findings, the patient was diagnosed with left-sided ulcerative colitis. This report describes a case of ulcerative colitis progressing from the initial lesion to typical left-sided colitis. We also discuss differential diagnoses of rectal granular lesions.
