title: "Mass-forming" variant of ischemic colitis is a distinct entity with predilection for the proximal colon.
abstract: We systematically evaluated the clinicopathologic features and outcome of a rare, unusual variant of ischemic colitis that presents as a mass lesion mimicking malignancy on imaging or colonoscopy. A retrospective search was performed for cases with a histologic diagnosis of ischemic colitis and a clinical impression of malignancy. Of the 23 patients initially identified, 4 were excluded because clinical and histologic review showed mucosal prolapse (n=1), discrete colon polyp (n=2), and a diverticular mass (n=1) without concern for malignancy. The mass-forming variant of ischemic colitis (n=19) was seen predominantly in elderly (mean age 71.8 y) women (63.2%) with a striking predilection for the right colon (13/19), particularly the cecum (n=6). Abdominal pain (52.6%) and hematochezia (26.3%) were the most common presenting symptoms. A computed tomography scan showed segmental thickening suspicious for malignancy in 6/8 patients. Colonoscopy revealed an exophytic (n=16) or stricturing (n=3) mass with a mean size of 4.67 cm. Mucosal biopsies showed features typical for ischemic colitis in all cases. A colectomy was performed in 4 cases. In 2, the mass-like appearance was due to marked submucosal and mural edema, whereas in the other 2 cases, with a malignant stricture-like lesion, marked submucosal fibrosis and cholesterol emboli were present. No malignancy was identified on follow-up in any patient (mean 39.9 mo). Follow-up colonoscopy was performed in 7 patients 1 to 32 weeks after initial presentation and showed resolution of the mass in all cases. Awareness of this rare variant of ischemic colitis will prevent unnecessary resections in these patients.
authors.affiliation: *Department of Anatomic Pathology, PathWest Laboratory Medicine, Nedlands, WA, Australia †Department of Pathology, Massachusetts General Hospital ‡Department of Pathology, Brigham and Women's Hospital, Boston, MA.
authors.forename: Tze S
authors.initials: TS
authors.lastname: Khor
authors.forename: Gregory Y
authors.initials: GY
authors.lastname: Lauwers
authors.forename: Robert D
authors.initials: RD
authors.lastname: Odze
authors.forename: Amitabh
authors.initials: A
authors.lastname: Srivastava
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D049109:Cell Proliferation; D003082:Colectomy; D017091:Colitis, Ischemic / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D003106:Colon / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007413:Intestinal Mucosa / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome