Helen M. Shen, MD1, Brian T. Lee, MD2, Gregory Idos, MD, MS3
1LAC+USC Medical Center, Los Angeles, CA; 2Keck School of Medicine, University of Southern California, Los Angeles, CA; 3University of Southern California Norris Comprehensive Cancer Center, Los Angeles, CA
Introduction: Inflammatory granulation polyps inside of a diverticulum are rarely reported in the literature. We report a case of a large inflammatory granulation polyp, which appeared to be a malignant polyp discovered inside of a diverticulum.
Case Description/Methods: A 65-year-old Hispanic female with a history of diverticulosis was referred from her primary care provider for a colonoscopy. The patient reported significant weight loss over the past year and had laboratory evidence of iron deficiency anemia (hemoglobin 11.7 g/dL, mean corpuscular volume 73.4 fL, ferritin 20 ng/mL, iron saturation 12%, TIBC 400 ug/dL). Prior records indicated that the patient underwent a colonoscopy that revealed multiple polyps within her colon. Given her worrisome presentation, a colonoscopy was performed. The colonoscopy was notable for three polyps as well as diverticulosis of the sigmoid colon. Two of the polyps were removed easily and returned as tubular adenoma. However, the third polyp was a large 10-millimeter raised lesion found inside of a diverticulum. The mucosa of the lesion was friable with a central ulcerated indentation, concerning for malignancy. Histology was notable for numerous blood vessels, neutrophils, lymphocytes, plasma cells, and reactive fibroblasts, consistent with an inflammatory granulation polyp. The patient was referred to colorectal surgery for further evaluation in the setting that endoscopic mucosal resection may not be plausible.
Discussion: Granulation polyps are more commonly observed in the setting of inflammation, such as inflammatory bowel disease, as well as in response to other insults such as infectious or ischemic etiologies. These polyps are difficult to distinguish from a neoplasm. Morphologically, they appear friable with overlying ulceration and exudate, mimicking submucosal invasive cancer. Similarly, our polyp had a classic appearance of malignancy as a sessile polyp with a centrally ulcerated indentation, concerning for submucosal invasion. Given the location of this polyp inside of a diverticulum, polypectomy may be technically challenging. Removal can be associated with an increased risk of bleeding or bowel perforation. There is no data regarding the malignant potential of these polyps in the setting of diverticulosis, although in the setting of inflammatory bowel disease, these polyps have intermediate risk. Although diagnosis is based on histology, endoscopists should be aware of this clinical entity and weigh the risks and benefits of resection versus surveillance.
Citation: Helen M. Shen, MD; Brian T. Lee, MD; Gregory Idos, MD, MS. P0392 - ATYPICAL POLYP WITHIN A DIVERTICULA: A HIDDEN CANCER COPYCAT. Program No. P0392. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.