[Non-typical tumor of the left kidney]

The paper presents the diagnosis and treatment of 62-years old male, admitted to the hospital with supposition of splenomegaly. X-ray of abdomen and urography showed in the location of left kidney irregularly calcified tumor with features of a huge mould concretion in the collecting system of the left kidney. After subsequent diagnostic procedures as: ultrasonography of abdomen, aortonephrography, CT, patient was qualified for surgical intervention. A large tumor (10 cm in diameter) with calcified walls, in part infiltrating mesenterium of large intestine suggesting neoplastic infiltration, was removed from extraperitoneal area. Histopathological examination identified the tumor as a defunct kidney filled with caseous masses, separated from the remains of kidney with calcified wall. No active tuberculosis was found in examined sections. The paper presents the problems in differential diagnosis of tumors localised in left hypochondrium.