R-N13A - Ovarian adenocarcinoma - ovary, oviduct - chicken
Signalment:  2 year old female sex-link chicken
History:  Died after a two day history of listlessness. She had a history of laying rubber eggs with tissue/blood.
Ovary: Ovarian tissue is multifocally effaced by an unencapsulated, densely cellular, infiltrative neoplasm composed of nest of polygonal cells forming irregular tubules and acini on a moderate fibrovascular stroma. Neoplastic cells have indistinct cell boarders, moderate amount of eosinophilic cytoplasm that often contains multiple 2-5 um round, eosinophilic cytoplasmic granules. (visible in less aulolytic areas) Nuclei are irregularly round with finely stippled chromatin and indistinct nucleoli. Anisocytosis and anisokaryosis are moderate and mitosis is less than 1 per 40 X HPF. Multifocally within the neoplasm are large areas of amorphous, eosinophilic material (secretory product)
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Morphologic Diagnosis:   Ovary: Adenoarcinoma.
- Most common ovarian neoplasm of the chicken
- Only affects the left ovary, (left is functional, right persists as a small vestige)
- The ovary is the most common site; magnum of the oviduct is second most common and very malignant.
- Oviduct contains five regions: Infundibulum (fertilization); magnum (deposition of albumen); isthmus (deposition of membranes); uterus (shell); and vagina (transport to the cloaca)
- Incidence increases with age and is up to 80% by 2 years of age in some breeds
- Incidence higher in breeds with high body weight and egg weight
- Metastasis, dissemination and vascular spread occur in 50% of cases.
- In turkeys long photoperiods stimulated tumor growth and short photoperiods caused regression to the point of remission. Tumor growth was attenuated by melatonin making this a good model for human spontaneous adenocarcinoma.
- Cell of origin thought to be overlying mesothelium or from thecal glands, interstitial cells, mesonephros or sex cord remnants.
- These tumors are estrogen responsive
Typical Clinical Findings:
- Abdominal distension (ascites)
- Dyspnea, depression
Typical Gross Findings:
- Ranges from small, fleshy, round enlargements of follicles to enlarged, firm, gray-white cauliflower-like ovarian masses
- Multifocal implants on serosal surfaces of pancreas, mesentery, and intestines.
Typical Light Microscopic Findings:
- Patterns include solid (most common), acinar, and papillary
- Infrequent mitotic figures
- Intracytoplasmic intensely eosinophilic and homogeneous material (PAS-positive and mucicarmine-negative). Mucicarmine: Very specific for epithelial mucins, including adenocarcinomas; although insensitive; stain contains carmine (red coloring material) and aluminum
- Foci of necrosis and hemorrhage
- Maturing follicles are usually absent in advanced cases
- Presumed to arise from the mesothelium of the ovary
- Pattern and cell morphology vary
- Most often acinar and tubular patterns
- Adenocarcinoma cells may penetrate through the muscularis and spread through the abdominal cavity. The muscular is mucosa under these implants becomes hyper plastic.
- Intracytoplasmic intensely eosinophilic and homogeneous material as above.
Additional Diagnostic Tests:
- Immunohistochemistry: Cytokeratin AE1/AE3, pancytokeratin, EGFR, Lewis Y, CEA, Tag 72, and erbB-2 are all reportedly positive with immunohistochemistry.
- Adenocarcinoma of oviduct origin are positive to ovalbumin, progesterone and estrogen receptors.
Gross ovarian neoplasm:
- Oviductal vs. ovarian adenocarcinoma: Failure to detect tumor growth on mucosal surface of oviduct strongly suggests that the primary tumor is ovarian.
- Adenocarcinoma of unknown origin
- Granulosa cell tumor: Can be very large; generally attached to the ovary by a thin stalk, yellow, lobulated, round, and encapsulated by a smooth, glistening membrane, friable; often hemorrhage and necrosis
- Arrhenoblastoma: Seminiferous tubules proliferating within ovarian stroma; associated with sex reversal in hens; variable degrees of spermatogenesis
- Leiomyoma of the mesosalpinx: Ovarian, oviduct and uterine tumors; grow on the peritoneal surface of the oviduct or in the mesentery; single, firm, encapsulated, round masses; occur in flocks on 17 beta-estradiol
- Mesotheliomas: Lack glandular structures
- Chickens serve as a model of spontaneous adenocarcinoma in humans.
- Turkeys are occasionally diagnosed with ovarian and oviduct adenocarcinoma.
- Canine: Ovarian adenoma/adenocarcinoma is rare.
1. Kennedy PC, Cullen JM, Edwards JF, Goldschmidt MH, Larsen S, Munson L, Nielsen S. Histological classification of the tumors of the genital system of domestic animals. In: Schulman FY, eds. World Health Organization, Histological Classification of Tumors of Domestic Animals. Vol. 4. 2nd ed. Washington, DC: The Armed Forces Institute of Pathology, 1998: 24-28.
2. Reece RL. Other tumors of unknown etiology. In: Calnek BW, Barnes HJ, Beard CW, McDougald LR, Saif YM, eds. Diseases of Poultry. 11th ed. Ames, IA: Iowa State University Press; 2003: 542-547