Ants in the Pants: Infectious and Inflammatory Lesions of GU Sites


This lecture will review infectious and inflammatory lesions in the genitourinary tract. Topics covered include Schistosoma-associated squamous cell carcinoma, ketamine associated cystitis, syphilis and its increasing frequency, inflammatory myofibroblastic tumor, and angiomyolipoma masquerading as expansile histiocytic inflammation. The implications and prognosis of Schistosoma-associated squamous cell carcinoma is compared to urothelial carcinoma. Ketamine cystitis is a rapidly growing problem with limited clinical recognition and profound impact on bladder health. The continued spread of syphilis across the U.S. has resulted in presentations in non-classical sites and the review covers diagnostic clues. Novel immunohistochemical methods and best practices are suggested for the diagnosis of ALK-positive inflammatory myofibroblastic tumor. Finally, we review a challenging clinical case with histiocytic inflammation nearly completely obscuring a clinically relevant neoplasm, angiomyolipoma.

Originally presented on February 8, 2023, in Park City, Utah.

Lecture Presenter

Jonathon Mahlow, MD

Jonathon Mahlow, MD

Assistant Professor
University of Utah School of Medicine
Medical Director, Anatomic Pathology
ARUP Laboratories

Dr. Mahlow is a staff pathologist at ARUP and an assistant professor of pathology at the University of Utah School of Medicine. He received his MD from Wayne State School of Medicine in Detroit, Michigan and completed his anatomic and clinical pathology residency training at the Cleveland Clinic Foundation in Cleveland, Ohio. Subsequently, he completed a fellowship in surgical pathology at the University of Utah. Dr. Mahlow is a member of several professional societies, including the United States and Canadian Academy of Pathology, and the American Society for Clinical Pathology.


After this presentation, participants will be able to:

  • Identify infection associated with malignancy and the implications on the GU tract
  • Discuss novel/emerging cause of injury to the bladder in at-risk patient demographics
  • Review epidemiologic data and “unusual/nonclassical” presentations of a common GU infection
  • Describe the impact of novel IHC in disease detection and understand potential profound treatment implications
  • Compare inflammatory lesions mimicking renal tumors and tumors inciting inflammatory response

Sponsored by:

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