Successful Management of Locally Advanced Primitive Neuroectodermal Tumor (PNET) of the Urinary Bladder: a Case Report and Literature Review

Abstract

Background: Primitive neuroectodermal tumors (PNETs) are highly malignant neoplasms arise from neuroectodermal cells that have cholinergic features. These tumours are closely related to osseous or extraosseous Ewing’s sarcomas, with which they share the same chromosomal abnormality. Over the last few years, PNETs have been increasingly reported to occur in various organs, which may be due to recent progress in immunohistochemical techniques. PNETs arising in the urinary bladder are extremely rare, but more frequent in older adults. Case presentation: A 16 years Moroccan men old, who consults for a total hematuria and dysuria evolving for 2 months in a context of deterioration of the general state. Cyst biopsy was performed. The morphological result in favor of an undifferentiated round cell tumor process infiltrating the bladder muscle, the immu-histochemical study was in favor of a round cell tumor of the Ewing sarcoma/PNET type. Pelvic Magnetic resonance imaging MRI revealed the presence of an endovesical process invading the left antero-inferior pre-vesical fat. We decided, after a multidisciplinary consultation meeting, to start with two cycles of neoadjuvant chemotherapy, then to propose locoregional treatment, either radiotherapy or partial resection. The patient was put on the VAC/IE protocol with a clear regression in tumor size after two cycles. Conclusion: Both clinician and pathologist must be aware of this rare entity during diagnosis and management. Surgery or radiotherapy supported with chemotherapy should be considered an option, especially in advanced disease. Studies of more cases of primary PNET of the urinary bladder with longer follow-up periods are needed to clarify the clinical features and treatment.