FNA/Core Biopsy of Soft Tissue: Let the Category be your Guide


Recognizing that there can be significant morphologic overlap between soft tissue entities is important and often humbling. This lecture will use a case-based review of some of the more common soft tissue diagnoses to serve as a guide for navigating soft tissue lesions and tumors. The diagnosis of soft tissue lesions is a team effort, requiring clinical and radiologic integration to help assist in the pathologic evaluation. There are instances where a definitive diagnosis cannot be rendered, yet an informative report to guide management can still be rendered.

By working to separate soft tissue lesions into distinct categories, something that can often by achieved on the cytomorphology of aspirations or touch preparations, can facilitate their pertinent ancillary workup. The main categories include stromal predominant, spindle cell, adipocytic, small round cell, epithelioid, and pleomorphic tumors. Once such a classification is made, the differential diagnoses can be narrowed to a scope that allows for targeted immunohistochemical and in FISH testing workups.

Originally presented on February 11, 2020, in Park City, Utah.

Lecture Presenter

Benjamin L. Witt, MD

Benjamin L. Witt, MD

Associate Professor of Anatomic Pathology (Clinical)
University of Utah School of Medicine
Medical Director, Anatomic Pathology and Section Head, Cytopathology
ARUP Laboratories

Dr. Witt is an associate professor of anatomic pathology at the University of Utah School of Medicine, where he serves as the Director of Cytopathology, the Section Head of Head and Neck pathology, as well as the residency rotation director for Cytopathology. Dr. Witt received his MD at the University of Colorado Denver, School of Medicine and completed his AP/CP pathology residency at the University of Chicago (NorthShore) where he served as the chief resident during his last two years. He also completed a cytopathology fellowship at the University of Utah/ARUP Laboratories, and is board certified in anatomic and clinical pathology, with subspecialty boards in cytopathology. His research interests include studies related to fine-needle aspiration and head and neck pathology.


After this presentation, participants will be able to:

  • Examine cytomorphology and core biopsy appearance to differentiate soft tissue lesions/tumors into general categories to help facilitate their diagnostic workup
  • Interpret selected immunohistochemical stains on core biopsy specimens to navigate the differential diagnoses
  • Perform fluorescence in situ hybridization (FISH) testing when appropriate to clinch certain diagnostic entities

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories