[Apparent spontaneous regression of an inoperable kidney cancer].

In 1959, a then 66-year-old woman was undergoing an operation of a renal "tumor". Because of inoperability, only a biopsy was performed. Histologically, a non differentiated hypernephroid carcinoma was diagnosed. 20 years later, in 1979, the patient died of biventriculary cardiac insufficiency. In the autopsy a retroperitoneal "tumor", affecting the kidney, was found and for the present (without knowledge of the anamnesis) diagnosed as a liposarcoma. In knowledge of history, duration and behaviour of the disease and histopathology of the lesion, the "tumor" in question showed to be a twice misdiagnosed retroperitoneal fibrosis (M. Ormond) and not a neoplasm.