A 77-Year-Old Man with a Pulse Granuloma of the Descending Colon Identified by Fluorodeoxyglucose-Positron Emission Tomography (FDG-PET) Imaging 19 Months Following Surgical Resection for Rectal Carcinoma.

BACKGROUND Food particles may sometime lodge in the intestinal wall, resulting in a granuloma. Pulse granuloma is associated with the seed of a legume and has a characteristic appearance on histology. This report describes a case of pulse granuloma of the descending colon identified by fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging. Imaging was done 19 months after surgical resection for rectal carcinoma, and the results of imaging alone suggested a tumor metastasis. CASE REPORT A 77-year-old man underwent sigmoid colostomy for sigmoid colon perforation due to obstruction by rectal cancer affecting the upper rectum approximately 2 years ago. Two months later, after his general condition improved, he underwent laparoscopic low anterior resection. On postoperative pathological examination, the lesion was diagnosed as stage II. Nineteen months later, computed tomography showed an irregular nodule on the dorsolateral side of the descending colon. FDG-PET revealed positive results, and peritoneal dissemination was suspected. Because the lesion was localized and there was no other evidence of metastasis, resection was performed. A pathological examination revealed a pulse granuloma with a central legume seed, and no obvious malignant findings were observed. CONCLUSIONS This report has highlighted the importance of imaging and histopathology in cases in which a solitary nodule is present in the bowel in a patient with previous successful treatment for malignancy. Pulse granuloma, or other types of granuloma associated with impacted food material, may be a cause of a solitary nodule, or pseudotumor, in the bowel wall.