<prompt> 1925. Causes of secondary polycythemia may includeChronic cor pulmonaleRenal carcinomaCerebellar haemangioblastomaAll of the above  <response>: Secondary polycythaemia occur due to high altitude,cardiovascular disease ,pulmonary disease with alveolar hypoventilation,heavy smoking,inappropriate erythropoietinrenal cell carcinoma ,hydronephrosis,hepatocellular carcinoma ,cerebellar hemangioblastoma ,massive uterine leiomyoma.. Reference :Harsh mohan textbook of pathology sixth edition pg no 359. 