Case ReviewsPolymorphous Low-Grade Adenocarcinoma Case Report and Differential DiagnosisAvadhani, Vaidehi MD; Zeizafoun, Nebras MDAuthor Information From the Department of Pathology, Mount Sinai Health System, Mount Sinai Roosevelt Hospital, New York, NY. Reprints: Nebras Zeizafoun, MD, Department of Pathology, Mount Sinai Roosevelt, 1000 Tenth Ave New York, NY 10019.E-mail: email@example.com. The authors have no funding or conflicts to declare. AJSP: Reviews & Reports: January/February 2015 - Volume 20 - Issue 1 - p 13-16 doi: 10.1097/PCR.0000000000000074 Buy Metrics Abstract Polymorphous low-grade adenocarcinoma (PLGA) is a low-grade malignant epithelial tumor that is the second most common malignant neoplasm of minor salivary glands. Diagnosis on biopsy remains challenging owing to histological similarities with other salivary glands, including benign and malignant neoplasms. The most important differential diagnoses to consider include pleomorphic adenoma, adenoid cystic carcinoma, low-grade papillary adenocarcinoma, cribriform adenocarcinoma of minor salivary glands, and mucoepidermoid carcinoma. Recently, a PRKD2 rearrangement was described in PLGA. The definitive treatment is complete surgical excision with negative clear margins. These tumors typically follow an indolent course and rarely metastasize but have a propensity to recur. The focus of this review is on the histopathologic features of PLGA and findings that might allow differentiation from histologically similar–appearing salivary gland neoplasms. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.