# Excision of an Unexpected Retroperitoneal Mass at Laparoscopy

## TL;DR

A rare case of a retroperitoneal neurofibroma was successfully removed during laparoscopic surgery, highlighting the importance of considering this diagnosis in pelvic masses.

## Contribution

This case report adds to the limited literature on solitary retroperitoneal pelvic neurofibromas and emphasizes diagnostic challenges.

## Key findings

- A 54-year-old woman had a retroperitoneal mass removed that was diagnosed as a neurofibroma.
- The mass was initially misinterpreted as a dermoid cyst on imaging.
- No recurrence was observed during follow-up after surgical excision.

## Abstract

Neurofibroma is a benign soft tissue tumour of neural origin. Neurofibromatosis or Von Recklinghausen disease is an autosomal-dominant condition. Pelvic occurrence of a solitary neurofibroma is uncommon.

A 54-year-old woman presented with a history of chronic back pain with occasional dyspareunia for 12 months. She had a hysterectomy and right salpingo-oophorectomy for endometriosis many years back. Clinical examination revealed fullness and tenderness at left vaginal vault. Pelvic ultrasonography revealed a 55x49x55mm mass suggestive of dermoid cyst. Magnetic resonance imaging findings were consistent with dermoid cyst. Intraoperatively, a retroperitoneal mass in the left pelvic sidewall was removed along with left fallopian tube and ovary. Histopathology revealed neurofibroma. There was no recurrence on follow-up.

Solitary, de novo, retroperitoneal pelvic neurofibroma is very rare. A lack of familiarity with the anatomy and pathogenesis of retroperitoneal masses often leads to a diagnostic conundrum due to overlapping imaging findings. A possibility of neurofibroma or schwannoma should be kept in mind while evaluating pelvic and/or adnexal masses.