Adductor Muscle Atrophy Due to Obturator Nerve Compression by Metastatic Lymph Node Enlargement-A Rare Complication of Recurrent Bladder Cancer

Advanced cancer frequently causes neuropathies or plexopathies if peripheral nerves are invaded. However, isolated obturator mononeuropathy in this setting is exceedingly rare. A 59-year-old male presenting with haematuria went on to have a cystoscopy and trans-urethral resection of a bladder tumour. Histological examination revealed a pT2 grade 3 transitional cell carcinoma, which necessitated a radical cystectomy with ileal conduit. After two cycles of adjuvant chemotherapy he developed severe paraesthesia in his right inner thigh. A pelvic MRI was performed which revealed atrophy of the right adductor muscle group with a proximal obturator node the likely cause of the denervation injury. Neuromuscular symptoms in the context of pelvic cancer should alert the clinician to nerve involvement from either local or metastatic disease. An MRI scan is the ‘gold-standard’ diagnostic test.