Synchronous presacral schwannoma and carcinoma cervix: A rare diagnostic and therapeutic dilemma

ABSTRACT

Schwannomas are benign, encapsulated tumors originating from Schwann cells of the peripheral nervous system. Pelvic and presacral schwannomas are rare, often clinically silent, and are frequently diagnosed incidentally or when they attain sufficient size to compress adjacent pelvic structures. Synchronous occurrence of a presacral schwannoma with cervical carcinoma in the same patient is exceptionally rare and poses significant diagnostic and management challenges. We present a 65-year-old postmenopausal woman (P7L7A1) who presented with per vaginal bleeding and was subsequently diagnosed with simultaneous FIGO (International Federation of Gynecology and Obstetrics) Stage IIIB carcinoma cervix and a 5.3 cm presacral pelvic mass. Biopsy of the cervical lesion confirmed squamous cell carcinoma (p16-positive, human papillomavirus (HPV)-associated). Repeat core needle biopsy of the presacral mass, followed by immunohistochemistry demonstrating strong S100 protein and SOX10 positivity, confirmed schwannoma. A multidisciplinary tumor board decided to prioritise treatment of the malignancy. The patient received definitive concurrent chemoradiotherapy (EBRT 50.4 Gy + concurrent cisplatin) followed by three sessions of high-dose rate intracavitary brachytherapy (7 Gy per fraction). Post-treatment imaging revealed excellent local response at the cervix, whereas the schwannoma demonstrated interval growth to 6.5 × 6.4 cm. Surgical resection of the schwannoma was planned following adequate recovery from radiation sequelae. This case highlights the importance of thorough diagnostic workup for incidentally detected pelvic masses in patients with gynecological malignancies, the value of multidisciplinary team discussion in prioritising competing pathologies, and the need to carefully consider how treatment of one pathology may affect the future management of the other.