Review ArticlesEpithelioid Vascular Lesions: The Differential Diagnosis and Approach in Cytology and Small BiopsiesTabish, Nabil MD, MS; Monaco, Sara E. MD Author Information Department of Laboratory Medicine, Geisinger Medical Center, Danville, PA The authors have no fundings or conflicts of interest to disclose. All figures can be viewed online in color at www.anatomicpathology.com Reprints: Sara E. Monaco, MD, Geisinger Medical Center, Danville, PA 17822 (e-mail: [email protected]). Advances In Anatomic Pathology: November 2022 - Volume 29 - Issue 6 - p 389-400 doi: 10.1097/PAP.0000000000000358 Buy Metrics Abstract Vascular neoplasms are rare tumors with a multitude of clinical presentations and behavior, which make accurate identification and subclassification challenging on limited small biopsies. Within the spectrum of these lesions, the ones with epithelioid morphology, such as epithelioid hemangioendothelioma and epithelioid angiosarcoma, are particularly challenging given the morphologic overlap with nonvascular lesions and the limited cells due to hemodilution on sampling. Herein, we review the differential diagnosis of epithelioid vascular neoplasms, with a focus on the cytomorphology, differential diagnoses, and ancillary studies that pathologists should be aware of when evaluating small biopsies and aspirates, including novel translocations, and associated monoclonal immunohistochemistry antibodies, that can help in the diagnosis of some of these tumors. Awareness of these morphologic and ancillary study findings in these rare tumors will hopefully allow pathologists to recognize and render-specific diagnoses on limited samples of these challenging lesions. Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.