Encountering "Dropped" Gallstones During Robotic-assisted Laparoscopic Radical Prostatectomy

We describe a case of an unusual finding during robotic-assisted laparoscopic radical prostatectomy and bilateral pelvic lymphadenectomy in a 66-year-old man with stage IIb (T2c, N0, M0) prostate adenocarcinoma. During the operation, intraperitoneal examination of the rectovesical pouch revealed calcifications and stones, which were subsequently identified as gallstones. Although these stones were not noted initially on this patient's preoperative multiparametric magnetic resonance imaging, a retrospective review demonstrated hypointense foci in the rectovesical pouch. Here, we describe the first reported case of visualization of dropped gallstones on a prostate multiparametric magnetic resonance imaging and retrieval during robotic prostatectomy.