[Retroperitoneal leiomyosarcoma. A rare differential diagnosis of an adrenal tumor].

A pararenal mass is a clinical finding that cannot be explored preoperatively regarding its parent organ even nowadays. We report in the following about a patient who was admitted with dull pain located in the flank and upper abdomen. Ultrasound investigation at admission showed a solid homogeneous mass close to the upper pole of the left kidney. Urinalysis and catecholamine levels were normal. Intraoperatively, a sarcoma infiltrating the renal capsule and renal vein was observed. In the case of a mass located in the area of the adrenal gland, an extra-adrenal tumor must be considered especially if there are normal findings for urinalysis and catecholamine levels even if modern imaging techniques had been applied.