Retroperitoneal primary adenocarcinoma of Mullerian origin: case report with radiology review

Retroperitoneum Mullerian neoplasms are extremely rare malignancies. We report a case of a 35-year-old woman who presented with a 12-year history of lower abdominal cystic lesion, presumed of renal origin and benign, as such was not followed for 10 years. Prior to pregnancy, the patient received additional imaging and the lesion was again redemonstrated and questioned to be of ovarian origin. As such, the patient underwent laparoscopy for planned cystectomy and was found to have normal ovaries. After pregnancy, the lesion had increased in size and surgical excision revealed that the cystic mass was retroperitoneal in origin. The histopathology was reported as microinvasive mucinous adenocarcinoma with Mullerian origin. Positron emission tomographic scanning, colonoscopy, and endoscopy were unrevealing. Tumor markers were followed and follow-up scans demonstrated no recurrence. The preoperative diagnosis of primary retroperitoneal adenocarcinomas of Mullerian origin is difficult, and a definitive diagnosis cannot be made without postsurgical histopathological analysis. However, it is important for radiologists to recognize imaging features of this entity and include it in the differential diagnosis. Here we report a case and review imaging features reported for retroperitoneal primary adenocarcinomas of Mullerian origin.