-

Objective: Diagnosis of a tumor mass of the ovary of a hen.
Design: Case study Animals: A 52-week-old layer hen from a 60000-Aryan-broilcr
breeder flock.
Procedure: Ten layer hen carcasses necropsied to find out cause of production drop in a broiler breeder flock. A tumor mass was encountered at the site of the ovary in one hen. Macroscopic
characteristics of the mass were recorded and fi0078ed in 10% neutral
buffered formalin paraffin blocks were made sectioned at 5t and stained with Haematoxylin and Eosin (H&E).
Results: Macroscopically, a solid, rough and relatively spherical
mass (5 cm in diameter) observed on the left ovary. The mass was
firm, lobulated and yellowish-white on the cut surface and was located craniomedially on the small intestine scrosa. The bird
showed no signs of virilism. The neoplastic cells were round to
polyhedral in shape with hyper chromatic nuclei and well-defined
nuclear membranes and prominent nucleoli microscopically. The cells had scanty, finely granular, eosinophilic and vacuolated cytoplasm. Fine fibrous septa separated the cells to tubular like
strictures or cord-like elongated strands, whose appearance was
identical to that of testicular seminoma. There were no metastases
to other organs
Clinical implications: According to morphologic characteristics, biclogical behavior and especially histopathologic findings, the
mass was diagnosed as dysgerminoina. The macroscopic and
microscopic findings were similar to the other reports. Further
studies are necessary for dysgerminoma to determine its significance and prevalence in poultry industry in Iran, J. Fac. Vet. Med. Univ.
Tehran. 58,2: 155-157, 2003.