Primitive neuroectodermal tumor/Ewing's sarcoma of the urinary bladder: A case report and its molecular diagnosis

Department of Urology, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
International Journal of Clinical Oncology (Impact Factor: 2.13). 11/2010; 16(4):435-8. DOI: 10.1007/s10147-010-0144-8
Source: PubMed


We report a rare case of primitive neuroectodermal tumor/Ewing's sarcoma (PNET/ES) arising from the urinary bladder. A 65-year-old man presented with hematuria and dysuria. Computed tomography revealed an enlarged invasive tumor at the base of the bladder. No additional abnormal findings were disclosed by other diagnostic imaging methods. The surgical specimens showed small round cell tumor with positive staining for MIC2 gene product (CD99). EWS-FLI1 fusion transcripts were detected by reverse transcriptase polymerase chain reaction and direct sequencing, confirming the diagnosis of PNET/ES. The patient developed swollen pelvic lymph nodes as well as multiple lung metastases at 8 months postoperatively. No effective results could be obtained even with systemic chemotherapy consisting of vincristine, ifosfamide, doxorubicin and etoposide (VIDE) based on the EUROpean Ewing tumour Working Initiative of National Groups 1999 (EURO-E.W.I.N.G. 99) multinational trial. The patient died of acute superior mesenteric artery thrombosis at 22 months postoperatively. PNET/ES could have been included in past cases of small cell carcinoma because of the difficulty in its differential diagnosis. Exact diagnosis is crucial for deciding the treatment strategy for rare bladder tumors consisting of small round cells.

11 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mesenchymal tumours of the urinary bladder and prostate are infrequent neoplasms. The body of literature is growing with isolated case reports and short series, and the majority of cases are benign neoplasms. Other than stromal tumour of uncertain malignant potential and prostatic stromal sarcoma, both neoplasms derived from the specific prostatic stroma, the mesenchymal neoplasms in these locations are identical to their counterparts seen in other organs. However, the limited amount of tissue generated by biopsy and rarity of mesenchymal lesions in these sites create unique diagnostic difficulties, while correct classification of the neoplasm often bears significant impact on prognosis and therapeutic strategy. In this review we summarise the diagnostic features, focus on the differential diagnosis, and highlight the potential diagnostic pitfalls of mesenchymal tumours of the bladder and prostate.
    No preview · Article · Dec 2012 · Pathology
  • [Show abstract] [Hide abstract]
    ABSTRACT: We report a rare case of Ewing's sarcoma (ES)/primitive neuroectodermal tumor (PNET) arising from the adrenal gland. A 17-year-old Japanese woman presented with left upper abdominal pain and high fever. Computed tomography and magnetic resonance imaging revealed a 15×10 cm tumor replacing the adrenal gland. Preoperative diagnosis was an adrenocortical carcinoma. Resection of the tumor was performed. We obtained the final diagnosis of ES/PNET by immunohistochemical molecular study with positive staining for the MIC2 gene product (CD99) and a Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangement. Local recurrence was observed one month after the surgery. The patient was then treated with systemic chemotherapy and localized radiotherapy.
    No preview · Article · Oct 2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear. Purpose: To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition. Material and methods: The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies. Results: Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results. Conclusion: pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.
    No preview · Article · Jul 2014 · Acta Radiologica
Show more