A 45-year-old woman presented to the urology department with voiding syndrome and recurrent urinary tract infections. The patient had a history of hypothyroidism, arterial hypertension on regular treatment with atenolol and enalapril, smoked 10 cigarettes a day and had undergone cholecystectomy. Physical examination revealed no pathological findings. Renal and bladder ultrasound was performed, showing irregular thickening of the bladder wall.

Cystoscopy was subsequently performed and revealed a small bladder with a neoformation of approximately 5 centimetres in diameter with a solid appearance on the left lateral side towards the back and anterior side, with an inflammatory appearance and poorly defined limits. In the abdomino-pelvic CT scan, a diffuse thickening of the bladder wall was observed, which was more significant on the left side. After contrast administration, diffuse uptake of the entire bladder wall was observed with marked enhancement of the left parietal mucosa. No mesenteric or retroperitoneal adenomegaly was observed. Urine cytology was negative on two occasions for tumour cells.

In view of these findings, transurethral resection of the bladder neoformation and random bladder biopsies were performed.
The samples obtained were sent for anatomo-pathological analysis, which showed diffuse proliferation of spindle-shaped and elongated cells at the level of the lamina propria, with large vascular neoformation; nodular structures consisting of an acellular eosinophilic material whose fibres are arranged in a swirling manner, constituting Wagner-Meissner bodies, in a concentric arrangement simulating nerve structures, were also observed. Immunohistochemistry confirmed that the spindle cells and Wagner-Meissner bodies were strongly positive for antiserum S-100, confirming the diagnosis of diffuse neurofibromatosis of the bladder wall.
The patient was referred to the internal medicine department for further investigation to rule out other manifestations of neurofibromatosis in other organs. In the same way, the patient is periodically followed up by the urology department to monitor the appearance of new neoformations.