1796 CASE SERIES OF PRIMARY PRIMITIVE NEUROECTODERMAL TUMORS OF THE KIDNEY

Abstract

INTRODUCTION AND OBJECTIVES: Primitive neuroectodermal tumor (PNET) of the kidney is a rare disease often characterized by a young age of onset and aggressive clinical course. Because there are few case series and the optimal management is not well defined, we reviewed the combined experience of two large tertiary centers in the diagnosis and management of pts with renal PNET. METHODS: Following IRB approval at the University of Pittsburgh and Memorial Sloan-Kettering Cancer Center, we conducted a retrospective review of pts with surgically managed renal PNET treated from 1998?2012. RESULTS: There were 5 female and 3 male pts diagnosed at a median of 38 years (21 – 71 years). All pts had symptoms at presentation including abdominal pain (87.5%), anorexia (67.5%), and hematuria (50%). An abdominal mass was palpable in 50%. At presentation, 2 pts had metastatic disease, 3 had an IVC thrombus, and 2 had a renal vein thrombus. One pt had a history of a spinal PNET treated six years prior. The average radiographic size of the renal masses was 13.5cm (8.3-23cm) and 6 were left sided. All pts underwent radical nephrectomy and 50% had concurrent resections of the pancreas (3), spleen (2), colon (1), diaphragm (1), and/or psoas (1). Lymph nodes were positive in 25%, negative in 12.5%, and not reported in 67.5%. Three pts underwent percutaneous biopsy and the diagnosis of PNET was made in all 3 cases. One pt who had preoperative chemotherapy had complete tumor necrosis on final pathology. FISH analysis demonstrated EWS-FLI-1 and EWSR1 rearrangements in 2 and 3 pts, respectively. Four pts received chemotherapy prior to and 4 after surgery based on guidelines for the Ewing’s family of tumors. Radiation was performed for adjuvant (n 2) and palliative purposes (n 1). Median follow up was 27 mths (2.7 – 175 mths). Two pts died of disease at a median of 22.5 mths after diagnosis. Kaplan Meier estimates for 3 and 5 year overall survival were 62.5%, respectively. CONCLUSIONS: Renal PNET is a rare tumor that should be considered in younger pts presenting with a large renal mass associated with an IVC thrombus. The diagnosis can be made by percutaneous biopsy but more commonly it is established after nephrectomy. Treatment is multi-modal and chemotherapy is based on the Ewing’s family of tumors guidelines. Pts who present with metastatic disease have a poor overall prognosis (Fig 1). Source of Funding: Steven Hanson Family Kidney Cancer Research Fund.