3050 Case of Vanishing Colonic Mass

Abstract

INTRODUCTION: We present a case of left sided colonic mass as a finding of colonic ischemia. CASE DESCRIPTION/METHODS: A 58 year old female with a past medical history of multiple sclerosis (MS) requiring tracheostomy and gastrostomy tube, non-verbal at baseline, seizure disorder, and constipation presented to the emergency room for one day of maroon stools as reported by her caretaker. On arrival, the patient was on hemodynamically stable. Physical examination revealed a slightly distended, but non-tender and non-tense abdomen with intact PEG tube site. Maroon stool was present on rectal exam. Her labs revealed a hemoglobin of 10.1 g/dL, platelets 301 × 103/mcL, BUN 14 mg/dL, Creatinine 0.3 mg/dL, and lactic acid 0.87 mmol/L. Computed tomography of the abdomen showed distal colonic distension up to 7.9 cm, a large stool burden resulting in fecal impaction throughout the distal colon and an area of focal narrowing in the sigmoid colon. The patient was admitted and given four liters of polyethylene glycol, one bottle of magnesium citrate solution, and tap water enema for bowel preparation. She continued to have maroon stools with a decrease in hemoglobin from 11.1 g/dL to 9.1 g/dL. A diagnostic colonoscopy was then performed which could only be completed to the hepatic flexure due to redundant colon. Upon withdrawal, a 6 cm partially obstructing mass was noted in descending colon which was biopsied the colon proximal and distal to it was tattooed with carbon black. Pathology showed acute inflammatory cellular debris, fibrin and blood. Given the inconclusive biopsies, a flexible sigmoidoscopy was done two days after the colonoscopy. The previously seen mass was not visualized. The site had an ulcerated lesion with granular, erythematous mucosa. Biopsies were obtained from edges as well as center of this lesion. Histology revealed ulcerated colonic mucosa, granulomatous tissue, fibrin and acute inflammatory cellular debris raising the possibility of ischemia. The patient remained stable without further bleeding and was safely discharged to her nursing facility. DISCUSSION: We believe the initial mass like lesion was rather a large clot which subsequently got sloughed off permitting visualization of underlying mucosa. This is a very rare finding. A few case reports and case series have described cases of colonic ischemia presenting as masses but mostly in the right colon. We present the first case of this finding in the left colon. This case provides an important differential diagnosis for colonic mass.