Endocrine Abstracts

Introduction: Neuroendocrine tumors (NETs) are rare tumors that originate in cells from the neural crest, widely distributed in the body. Genitourinary (GU) NETs occurring in the bladder represent less than 1% of these primary malignancies. We present the case of a patient with two metachronous bladder tumors, of which one is NET.

Case report: Male patient, 52–year-old, ex–smoker, known with hypertension, dyslipidemia and benign prostatic hyperplasia came to our clinic following the diagnosis of a neuroendocrine tumour of the bladder. Three years prior to presentation, after gross hematuria, transurethral resection of a bladder tumor (TURB) was performed. The histopathological examination revealed urothelial carcinoma of high grade (G3) infiltrating the lamina propria, with patterns of glandular differentiation; no invasion in the muscularis propria. After surgery, the patient developed left orchitis. 10 months later, imaging follow-up identified a second bladder tumor for which TURB was performed again. The histopathological examination revealed small cell neuroendocrine carcinoma (SCC) with immunoreaction positive for synaptophysin, chromogranin and p16 and a Ki-67 index of 95%. The patient refused radical cystectomy and underwent 4 cycles of Cisplatin and Etoposide combination chemotherapy, well tolerated. Whole body positron emission tomography was negative – the investigation was, however, inconclusive, because of the physiological urinary elimination of radiopharmaceutical. Native computed tomography of the thorax and abdomen and contrast-enhanced magnetic resonance imaging of the pelvis confirmed the absence of recurrent or metastatic disease. No preoperative neuroendocrine tumour markers values are available, but following the second surgery, serum chromogranin A, serotonin, neuron-specific enolase and urinary 5-hydroxyindoleacetic acid are within reference range. Ecocardiography showed hypertensive cardiomyopathy. The patient denies symptoms of carcinoid syndrome.

Conclusion: GU NETs are very rare and usually affect women. Moreover, male GU NETs commonly involve the prostate. Last, but not least, SCC is an aggressive neoplasm that usually occurs at advanced stages, in senior population (male: female ~ 3:1) and, in approximatively 50% of cases, it is mixed with urothelial carcinoma, adenocarcinoma, squamous cell carcinoma, and/or may have sarcomatoid features. Thus, the only features in accordance with the literature are the patient’s gender, history of cigarette smoking and no association with paraneoplastic syndromes. In conclusion, bladder SCC is a rare tumour whose generally poor prognosis was much improved in this case by diagnosis and treatment in the presymptomatic and presecretory stage. The peculiarity of the case further consists of the high Ki-67 index (95%) and history of urothelial carcinoma.