Mixed epithelial and stromal renal tumour in a 12-year-old boy

Mixed epithelial and stromal tumour of the kidney (MESTK) is a rare kidney neoplasm that occurs almost exclusively in perimenopausal women. Long-term oestrogen replacement appears to play a major role in its pathogenesis. Around 70 cases have been described in the international literature, none of which involve male children. Herein, we describe an atypical case of MESTK diagnosed in a 12-year-old prepubertal boy who presented with hematuria. Pathology and immunohistochemistry revealed a typical MESTK. The child was free of disease at 2-year follow up after a partial nephrectomy and tumour excision.