A 75-year-old man with a history of moderate COPD and no other medical history of interest. Among the toxic habits, he was a smoker (20 packs/year) and a non-drinker. No environmental risk factors or family history.
The patient presented with urethrorrhagia and inability to urinate, for which reason he went to the Emergency Department. Given the impossibility of urinary catheterisation, a suprapubic size was placed and the patient was subsequently examined. An ultrasound scan was performed showing a large bladder balloon with an apparent single diverticulum similar in size to the bladder (greater than 13 cm maximum diameter) with several parietal polypoid images smaller than 2-3 cm in both the bladder and the diverticulum, findings suggestive of bladder neoplasia.
In view of the ultrasound findings and urethral stricture, a ureterotomy and cystoscopy were performed, where a solid tumour measuring almost 7 cm was observed, calcified on the lateral side, and a transurethral resection was performed at the same time, with residual disease being observed on the spot.
The anatomopathological result was inconclusive, but immunohistochemical analysis of the sample showed negative results for epithelial markers and positive results for fibroblastic markers: vimentin and actin, all compatible with reactive fibroblastic proliferation or solitary fibrous tumour. With the results obtained, it was decided to complete the surgery, and at that time, it was decided to perform a partial cystectomy and diverticulectomy, with the following anatomopathological result: low-grade leiomyosarcoma (mitosis =3 X10 high magnification fields). Marked cellular pleomorphism. Foci of intratumoral necrosis and multiple images of isolated cell necrosis. Extensive areas of myxoid change. Intense intra- and peritumoural inflammation. Infiltration of the entire thickness of the diverticular wall down to the peridiverticular adipose tissue causing peritumoural fibrotic reaction. Surgical margins free of tumour.
Immunohistochemistry
The tumour cells expressed positivity for markers of muscle differentiation (vimentin and actin) and were negative for desmin and epithelial markers (EMA and High Molecular Weight Cytokerqatins). With the result obtained of low-grade leiomyosarcoma with infiltration of all layers, the case was presented to the clinical committee, opting to administer complementary treatment to the patient given the high risk of the patient. In addition, the extension study was completed by performing a thoracoabdominal CT scan, a bone scan and a pelvic MRI, which did not show distant disease.
It was decided to administer locoregional radiotherapy and complementary chemotherapy. The patient received locoregional radiotherapy at a dose of 57 Gy. The chemotherapy administered consisted of the combination ifosfamide-adriamycin at the usual doses, with the patient receiving three cycles of this treatment. Once treatment was completed, the patient continued to undergo strict check-ups with periodic cystoscopies, urinary cytology and periodic thoraco-abdomino-pelvic CT scans.
After a period of 22 months, the patient continues to be disease-free and undergoes regular check-ups and is asymptomatic and has an excellent quality of life.

