(032) A Large Retroperitoneal Schwannoma Masquerading as Genito-Urinary Syndrome of Menopause
Authors: Khalife T , Hagen A 
Published: June 2023

Abstract

Introduction
Retroperitoneal schwannomas are extremely rare, slow growing, benign, neurogenic tumors. Their diagnosis is challenging and often incidentally found upon evaluation of vague symptoms. Extrinsic compression to nearby organs or nerves may cause pain and paresthesia. Vulvar pain as a presenting symptom of a retroperitoneal schwannoma is reported in the literature in a case with pudendal nerve involvement. Here we present a case report of a patient who presented with vulvar burning and lower urinary tract irritative symptoms which was found to have a large infra-hepatic retroperitoneal schwannoma.

Objectives
In this report we show case how performing a detailed neurological evaluation and having a good understanding of the vulvar, perineal, and lower extremity dermatomal innervation have assisted in early diagnosis and treatment of a large retroperitoneal schwannoma.

Methods
A 65-year-old menopausal woman presented to her primary provider for a 3-month-history of worsening vulvar burning sensation associated with urinary burning, frequency, and nocturia. The pain is worse at night and when sitting for more than an hour. The patient endorsed low back pain that radiated like pins down her anterior thighs. The patient underwent evaluation by her referring provider to rule out a urinary tract infections and vaginitis. She was treated with vaginal estrogen tablets with partial relief for a working diagnosis of Urogenital Syndrome of Menopause. Patient was then referred to Gynecology due to inadequate relief. A detailed pelvic examination revealed normal labia majora and minora with no erythema or swelling. The Vestibule, Bartholin and Skene glands were non tender. Q-tip testing provoked burning sensation in the left and right labia minora on the medial and lateral aspect as well as the labia majora. Pelvic Floor evaluation elicited left pelvic floor tenderness and bilateral ischial spine pain concerning for Pudendal neuralgia. Also, noted paresthesia overlying the left lower extremity at the L3 and L4 distribution at the medial thigh (Figure-1) The patient underwent a bilateral pudendal block with total resolution of her vulvar pain for 24 hours and hence, lumbar and pelvic nerve entrapment was suspected. Magnetic Resonance Imaging was requested. Evaluation revealed a 3.3x4.4cm left ovarian mass and uterine fibroids that could potentially explain L2-L5 radiculopathy. The Lumbar MRI noted a cystic mass in the right mid abdomen for which further evaluation with CT scan was recommended. (Image-1). Referral to Surgical Oncology and Gyn oncology was sought. Epithelial ovarian cancer tumor markers were normal. Catecholamine studies were nonrevealing except for unexplained increase in dopamine levels.

Results
Surgical excision of the retroperitoneal and ovarian tumor revealed a left ovarian Fibroma and Schwannoma with Cystic Degeneration, confirmed with Immuno-peroxidase studies for S100 and SOX10. The patient had an uncomplicated post-operative course and remains asymptomatic with total resolution of her urinary and vulvar burning symptoms.

Conclusions
This a case report of vulvar and urethral paresthesia caused by an exceedingly rare tumor located high in the retroperitoneum. Diagnosis was aided by detailed history, comprehensive gynecological, and neurodermatomal evaluation. Appropriate imaging and timely referral led to early diagnosis and treatment, resulting in symptom resolution.

Disclosure
No.