A 67-year-old woman with a personal history of appendectomy, herniated disc and hiatus hernia, fracture of the tibia and fibula, as well as right renal colic attended urology for a check-up. In the ultrasound study, a solid neoformation was observed in the right kidney measuring 5 cm; a CT scan was performed which showed a mass at the cortical level of the right kidney, measuring approximately 5 cm, with lobulated external borders, which did not appear to affect the perirenal space, with no adenopathy or dilatation of the renal excretory tract. With the diagnosis of probable hypernephroma, a radical right nephrectomy was performed laparoscopically.

Macroscopic examination revealed a cortical neoformation with a maximum diameter of 5 cm, well-defined but not encapsulated, deforming the cortical surface without passing through it, with a yellowish cut surface with areas of haemorrhagic appearance and cystic areas.
Microscopically, the neoformation consists of acinar structures lined by small uniform cuboidal cells with scant cytoplasm and nuclei with uniform chromatin, immersed in a slightly cellular stroma. Immunohistochemistry was performed to determine vimentin, cytokeratin 7, broad spectrum cytokeratin, CD34, chromogranin and EMA (Master Diagnostic. Granada. Spain), showing generalised expression of vimentin, focal expression of cytokeratin 7 and EMA in the epithelial cells, and CD34 in the stromal component.

The patient had an uneventful postoperative course and was asymptomatic 24 months after the operation.

