[Hydatid cyst and renal adenocarcinoma: an exceptional association]

Presentation of one case of an exceptional association in the same renal unit of a hydatid cyst and an adenocarcinoma, in a female patient who arrived to the emergency service with a picture of haematuria and lower back pain. The paper discusses the diagnostic complications posed by the large central necrotic component of the tumour, the adjacent position of both lesions and, basically, the initial intention of performing conservative surgery after it was demonstrated that the patient had mild renal insufficiency and simple cysts in the other kidney. In the end, faced with the perioperative finding of a neoplastic-like mass, radical surgery was performed. Analysis of the diagnostic and therapeutical difficulties with complex cystic masses in general.