Prostatic Adenocarcinoma Presenting as a “Giant” Abdominal Mass on PSMA PET/CT

We report a 75-year-old man who presented with an abdominal mass associated with urinary retention. Physical examination revealed an enlarged prostate. Bedside ultrasound demonstrated a very large abdominal-pelvic mass inseparable from the bladder. PSA levels were high at 2393 ng/mL. Transrectal ultrasound-guided biopsy confirmed prostatic acinar adenocarcinoma (Gleason 4+5). PSMA PET/CT scan showed a large, intensely PSMA-avid abdominal-pelvic mass involving the prostate, seminal vesicles, and bladder, with peritoneal metastasis. No osseous metastasis was noted. This case highlights how prostatic adenocarcinoma can present as a giant abdominopelvic mass, clearly illustrated on PSMA PET/CT.