Primitive neuroectodermal tumour of the kidney: An unusual case mimicking renal angiomyolipoma with minimal fat

Abstract

Primitive neuroectodermal tumour (PNET) is a highly aggressive neoplasm that develops classically in the central nervous system. PNET of the kidney (rPNET) is extremely rare. Recently, a 23-yearold woman complained of left flank pain and intermittent hematuria for 3 months and was admitted to our hospital. A computed tomography (CT) scan and magnetic resonance imaging demonstrated a 5.1 × 4.4-cm heterogenous mass with unconspicuous reinforcement in the upper pole of the left kidney. F18-FDG positron emission tomography CT (PET-CT) revealed the mass as a benign lesion with internal extensive bleeding. Renal angiomyolipoma with minimal fat was diagnosed. Three months later, a CT scan showed that the mass shrank to 3.1 × 2.6 cm and nephron-sparing surgery of the left kidney was performed at the patient's request. However, histologic features and immunohistochemical analysis confirmed the diagnosis of rPNET. Five cycles of combined chemotherapy were executed. At the 11-month follow-up, the patient showed no evidence of metastasis or recurrence.

Renal Primitive Neuroectodermal Tumor or Renal Ewing Sarcoma

“…2 Multimodal therapeutic approaches consisting of surgical resection, chemotherapy and radiotherapy are required depending on the primary site and stage. 1 The most commonly administered chemotherapy is vincristine-doxorubicin-cyclophosphamide, followed by itoposide-ifostamid. 14 The outcome is significantly associated with disease group of patient, tumor size, presence of tumor thrombus, distant metastasis and the use of chemotherapy.…”

“…Ewing sarcoma family tumors (ESFTs) previously called primitive neuroectodermal tumor, Askin's tumor or Ewing sarcoma is a rapidly growing, aggressive malignant round cell sarcoma of presumed neuroectodermal origin. 1 ESFTs occur mostly in bone and soft tissue and rarely occur in extraskeletal location like kidney, urinary bladder, heart, lung, central nervous system and genitourinary system. These organs contain neuroendocrine cells or cells of embryonic neural creast.…”

Renal Primitive Neuroectodermal Tumor

“… 23 Nephron-sparing surgery performed in early renal PNET has also been reported and indicated a favorable outcome. 24 The current adjuvant chemotherapy regimens of renal PNET include vincristine, doxorubicin, and cyclophosphamide substituted by ifosfamide or etoposide. 25 Importantly, the high rate of noncompliance with chemotherapy has been shown in previous report as well as in the current case, which should be considered while applying the therapy.…”

A Rare Case of Primitive Neuroectodermal Tumour (Pnet) of Kidney with Review of Literature

“…In 85 to 90% cases of Ewings family tumours, a recurrent chromosomal translocation, t (11; 22) (q24; q12), fuses the 5' portion of the EWSR1 gene on chromosome 22 to the 3' portion of the FLI1 (friend leukemia integration locus-1) gene on chromosome 11wich can be detected by flouresceneinsitu hybridization. Using a large panel of immunohistochemical markers is often essential [cytokeratin, EMA, WT1 (Wilms tumour 1), synaptophysin, muscle specific actin, desmin, myogenin, leukocyte common antigen (LCA) and CD45] to exclude other round cell tumours because of their important similarities [1][2][3][4][5][6][8][9][10][11][12][13][14] . Differential diagnosis of renal PNET includes wilms tumour, neuroblastoma, clear cell carcinoma, lymphoma, rhabdomyosarcoma, small cell variant of osteosarcoma and small cell anaplastic neuroendocrine carcinoma.…”

“…Prognostic factors are tumour stage, grade, patient's age, extent of surgery, surgical margin status and treatment beginning time [2,11] . The 5-year disease-free survival rate is 45% to 55% and median relapse free survival is 2 years in patients with metastatic disease [1,9] . There are no standard guidelines for the treatment of renal PNET [11] .…”