Primary Ewing's sarcoma/Primitive neuroectodermal tumour of the kidney: Report of four cases from a tertiary care centre.

Ewing's sarcoma /Primitive neuroectodermal tumours (ES/PNET) are categorized as small round cell tumours which commonly occur in bone and soft-tissue. Primary renal ES/PNET are uncommon with less than 150 cases reported till date. We received 1575 tumour nephrectomy specimens (radical and partial) from the year 2014 to 2020 in our department, out of which 4 cases were diagnosed as ES/PNET (frequency of 0.25%). In this case report, we discuss the clinical course and the pathological findings of these cases. We had three young adults and one paediatric case ,with mean age of 21 years and with male:female ratio of 1:1. The size of the tumour in our series ranged from 7 cm to 16 cm with a mean of 12 cm. Three of the four tumours were limited to kidney. Therefore, they underwent radical nephrectomy followed by chemotherapy. One patient had an advanced stage disease with local invasion and distant metastasis. She was treated with pre-surgical neoadjuvant chemotherapy and subsequent cytoreductive surgery in view of the extensive nature of the disease. However, the patient succumbed to the disease 3 months post-surgery. In view of the aggressive nature and poor prognosis of this disease, a multidisciplinary approach is recommended for early diagnosis and timely treatment.