P-118 Pathologists and Gastroenterologists May Disagree on Diagnosis of Dysplasia Associated Lesion or Mass: A Diagnostic Disagreement with Important Management Implications. (March 2016) - Waseem, Najeff
Abstract : Background: Inflammatory bowel disease (IBD) patients are at an increased risk of developing colorectal cancer (CRC) compared to the general population. There are various precursor lesions for CRC including sporadic adenomas, flat dysplasia, and dysplasia-associated lesions or masses (DALMs). Adenomas can develop in the colon of IBD and non-IBD patients and are managed with polypectomy. DALMs, specific to IBD patients, portends a high risk for occult CRC and is an indication for proctocolectomy. Accurate diagnostic agreement between the gastroenterologist and pathologist is necessary to ensure appropriate management. This study compared classification of colonic neoplastic growths by gastroenterologists with the histologic diagnosis of the same lesions by pathologists. Methods: Using an electronic medical record, we conducted a retrospective review of surveillance colonoscopy and surgical pathology reports of IBD patients who had a surveillance colonoscopy in a one-year period at an urban university medical center. Patients were excluded if the colonoscopy report could not be matched to an outpatient medical record. Patient demographics, IBD history, and colonoscopy and pathology findings were recorded in a Microsoft Excel database that maintained patient confidentiality. Dysplastic lesions classified by both university faculty gastroenterologists were noted. University faculty pathologists' classification of dysplastic lesions as either sporadic adenoma or DALMs were recorded. Statistical analysis was performed using Cohen's kappa statistic. The study was approved by the university's Institutional Review Board. Results: There were 136 patients. Dysplastic lesions were detected in 16 (11.8%). Among them, 10 patients (62.5%) were determined to have adenoma by both the pathologist and gastroenterologist. Six patients (37.5%) were diagnosed with DALMs by the pathologist. In comparison, 4 patients (25%) were determined to have DALM by the gastroenterologist. There was agreement between pathologist and endoscopist in 14 of 16 (87.5%) dysplastic lesions (κ = 0.714). The physicians conferred on 2 discordant diagnoses by reviewing the endoscopic findings and biopsies of nearby mucosa, and determined them to be sporadic adenomas. Therefore, 2 (33.3%) lesions initially classified as DALMs by the pathologist were reclassified as adenomas. Conclusions: Our study found substantial agreement between the endoscopist and pathologist in diagnosing dysplasia in IBD patients. Agreement was not, however, complete and 2 patients were initially diagnosed with DALM when their lesions were truly sporadic adenomas. This distinction carries important management consequences. The resection of a sporadic adenoma constitutes complete management, but resection of a DALM leaves behind a significant risk for the development of colorectal cancer. Labeling it an adenoma would provide inappropriate reassurance to the patient. Conversely, a sporadic adenoma mislabeled as DALM may lead to unnecessary colectomy. While the gastroenterologist and pathologist agree on the character of neoplasm in 87.5% of cases, the few discordant diagnoses highlight the importance of collaboration and communication between physicians in arriving at an accurate diagnosis.