Congenital mesoblastic nephroma (CMN), light micrograph. CMN is a mesenchymal neoplasm of the kidney that usually presents by the age of 6 months. It is the most common congenital renal neoplasm. Three histologic variants have been described - classic (25%), cellular (65%), and mixed (10%). It has excellent prognosis with 95% survival rate following complete resection. This image shows cellular variant of CMN and shows plump spindle or ovoid cells arranged in densely packed sheets. They have eosinophilic cytoplasm and ovoid or round vesicular nuclei with punctate nucleoli. Mitotic figures are easily found. The cellular variant resembles infantile fibrosarcoma and carries ETV6-NTRK fusion.