[Hepatoma in artificially raised trout].

Cases were described of a hepatoma in the liver of trout, Salmo irideus, Gibb., originating from three fish-breeding farms in the district of Sofia. Histologically, three were tumor cells arranged in the form of trabeculae and paths or distributed focally. The tumorous growths had trabeculous, more rarely alveolar structure. Some of the neoplasms had carcinomatous character. The tumor stroma had weakly developed, however, in some parts three was rich fibrous stroma, and the gross appearance resembled fibroadenoma. Infiltrative growth was also observed. It is concluded that the hepatoma observed in poikilothermic animals (rainbow trout) is similar to the liver tumors found in birds and mammals.