Primary Large Cell (Atypical) Ewing Sarcoma/Primitive Neuroectodermal Tumour of Kidney ED05-ED07
Dr. Reema Bhushan,
1113, Sector-4 RK Puram, Delhi-110022, India.
Primary Ewing Sarcoma/Primitive Neuroectodermal Tumour (ES/PNET) of the kidney is a rare entity. Here we describe a case of renal ES/PNET in 10-year-old girl who complained of abdominal pain and lump for a month. Contrast Enhanced Computed Tomography (CECT) revealed a huge heterogeneous solid cystic mass in the right kidney. We received a distorted specimen of kidney with rupture at upper pole and lateral wall. Sections from the renal mass showed an unencapsulated tumour separated into multiple nodules by thin fibrous septa with areas of extensive haemorrhage and necrosis. The tumour was composed of large round cells with moderate amount of clear to eosinophilic cytoplasm, round to irregular nucleus showing moderate to marked nuclear pleomorphism, coarse granular chromatin and prominent nucleolus. Mitotic figure were 3-4/10 high power fields. Differential diagnosis of large cell lymphoma, malignant melanoma, rhabdoid tumour, rhabdomyosarcoma and atypical ES were considered. Immunohistochemistry revealed diffuse strong positivity for CD99 with focal positivity for vimentin, Neuron Specific Enolase (NSE) and Cytokeratins (CK). Periodic Acid Schiff (PAS) stain showed intra cytoplasmic glycogen in few cells. Hence, the final diagnosis of large cell (atypical) ES/PNET was given. This case report highlights rare occurrence of primary renal large cell (atypical) ES/PNET.