Review ArticlesMucous Gland Adenoma: The Spectrum of Growth Patterns and the Diagnostic ChallengesZaleski, Michael P. DO; Kalhor, Neda MD; Moran, Cesar A. MDAuthor Information Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX The authors have no funding or conflicts of interest to disclose. All figures can be viewed online in color at www.anatomicpathology.com. Reprints: Cesar A. Moran, MD, Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030 (e-mail: email@example.com). Advances In Anatomic Pathology: November 2020 - Volume 27 - Issue 6 - p 371-379 doi: 10.1097/PAP.0000000000000283 Buy Metrics Abstract Mucous gland adenomas represent a small percentage of primary lung neoplasms. The accurate diagnosis of these benign tumors can be challenging not only on resected specimens but also more challenging in small bronchoscopic biopsies. If to that problem we add the issue that these tumors may also exist in the periphery of the lung, then it is easy to conclude that there is much difficulty in properly diagnosing these tumors with a core needle biopsy. Furthermore, there is little knowledge on the immunohistochemical properties and radiologic features of these tumors. Therefore, pathologists need to be aware of the spectrum of histopathologic features in these tumors and place them in perspective regarding the proper radiologic and immunohistochemical correlations. Needless to say, mucous gland adenomas exhibit a gamut of histopathologic features that can be easily confused with other more common tumor of the lung. Therefore, awareness of such features become essential in a benign tumor that is essentially diagnosed on morphologic grounds. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.