Impact of Referral Center Pathology Review on Diagnosis and Management of Patients With Appendiceal Neoplasms

A large proportion of appendiceal neoplasms are first identified during pathologic review of appendectomies performed for presumed benign causes. The most common include well-differentiated neuroendocrine tumors ('carcinoids'), mucinous tumors, goblet [...]
* Context.--Data regarding the clinical impact of subspecialist pathology review of appendiceal neoplasms are limited. Objective.--To determine whether pathology review by gastrointestinal pathologists at a tertiary-care referral center resulted in significant changes in the diagnosis and clinical management of appendiceal neoplastic lesions. Design.--We conducted a retrospective review of all patients with an initial diagnosis of appendiceal neoplasm referred to a tertiary-care referral center in Ontario, Canada, from 2010-2016. The discordance rate between original and review pathology reports, the nature of discordances, and the impact of any discordance on patient management were recorded. Results.--A total of 145 patients with appendiceal lesions were identified (low-grade mucinous appendiceal neoplasm [n = 79], invasive mucinous adenocarcinoma [n = 12], 'colorectal type' adenocarcinoma [n = 12], goblet cell carcinoid and adenocarcinomas ex goblet cell carcinoid [n = 24], and other lesions/neoplasms [n = 20]). One or more changes in diagnoses were found in 36 of 145 cases (24.8%), with changes within the same category of interpretation (n = 10), stage (n = 7), grade (n = 6), and categoric interpretation (n = 5) being the most common. In 10 of 36 patients (28%), the diagnostic change led to a significant change in management, including recommendation for additional surveillance, systemic chemotherapy, additional surgery, or discontinuation of surveillance. Conclusions.--Subspecialist pathology review of appendiceal neoplastic lesions led to a change in diagnosis in 36 of 145 cases (24.8%), of which nearly 30% (10 of 36 cases) led to a change in clinical management. The overall rate of clinically significant discordances was 7% (10 of 145). Our findings suggest that subspecialist pathology review of appendiceal neoplasms referred to specialized centers is justified. (Arch Pathol Lab Med. 2020;144:764-768; doi: 10.5858/arpa.2019-0214-OA)