cases, prostate Week 258: Case 4 April 26, 2023 pathadmin 1. Presented by George Netto, MD and prepared by Shien Micchelli, M.D.A 78 year old underwent prostate biopsies for elevated PSA. The below illustrated spindle cell proliferation was positive for ER, PR, muscle specific actin (weak) and negative for CD34, C-Kit and S100./images/2_27_06_4a.jpg/images/2_27_06_4b.jpg/images/2_27_06_4c.jpgGastrointestinal stromal tumor (GIST)Solitary fibrous tumorNeurofibromaStromal tumor of unknown malignant potential (STUMP) Loading...