Iliopsoas Mass, Hydroureter, and Back Squats: Using Biomechanics and Diagnostic Persistence to Diagnose a Germ Cell Tumor.

Lesions in the iliopsoas compartment carry a broad differential diagnosis, including infection, tumor, or hematoma, and less commonly, retroperitoneal fibrosis, atrophy secondary to paralysis or muscle disease, foreign body, calcifications secondary to trauma, or rhabdomyolysis. Iliopsoas lesions are oftentimes accompanied by nonspecific symptoms, resulting in a delayed diagnosis. We present the case of a 43-year-old male with acute radiating groin pain who was found to have a traumatic iliopsoas hemorrhagic lesion causing ureteral compression and ureteral dilatation, all presumably originating from a new-onset weight-training program. The patient had a drain placed for fluid removal and decompression, with the initial pathologic specimen confirming muscle fibers and an inflammatory process. Further patient symptomology with combined imaging and pathologic persistence yielded a diagnosis of a germ cell tumor. The importance of a plausible differential diagnosis combined with clinical diagnostic persistence must be stressed to all clinicians. Our patient's unrelenting inguinal pain led to a justified repeat psoas mass biopsy, imaging, and laboratory workup that led to a diagnosis of psoas germ cell tumor and immediate chemotherapy plan.