NEOPLASTIC DISEASES IN CHICKENS 55 



SUMMARY AND CONCLUSIONS 



A collection of 384 cases of spontaneous neoplastic disease found in 365 chickens 

 has been studied. Since most of the material was submitted to the diagnostic 

 laboratory of Massachusetts State College, some information was gained on the 

 relative incidence of neoplastic disease among birds submitted for necropsy. 

 An incidence rate of 12.9 percent for neoplastic disease was found in 2304 chickens 

 over six weeks of age that were examined in the laboratory. 



Twenty-five different kinds of neoplasms were found. Lymphocytoma was 

 the most common and accounted for 55.5 percent of the 384 cases. Six other 

 varieties (leiomyoma, embryonal nephroma, myelocytoma, leukosis, epithelio- 

 blastoma, and fibrosarcoma) accounted for 33 percent of the tumors. Each of 

 the varieties of neoplasia is described and the data compiled for study. The 

 incidence of neoplasia was studied in relation to various factors, such as age at 

 necropsN', sex, seasonal occurrence, and breed. Each of these appeared to be of 

 significance in one or more types of tumor. 



In some of the cases tentative diagnoses, based on m-acroscopic examination 

 onh', were later correlated with the fina' diagnoses in an eflfcrt to determine the 

 accuracy of such tentative diagnoses. The results, together with sources of 

 error, are discussed. 



The data on lymphocytoma provided a basis for a possible explanation of the 

 different forms of this disease. Other neoplasms on which new information of 

 significance was found were leiomyoma, neurogenic sarcoma, and carcinosarcoma. 



It may be concluded that spontaneous neoplastic disease in the chicken is 

 relatively common and that, although hmphocytoma is the most common and 

 causes the most loss, the other kinds are responsible for a significant share of the 

 loss due to neoplasia. 



REFERENCES 



1. Cappell, D. P., and Montgomery, G. L.: On rhabdomyoma and myo- 



blastoma. Jour. Path, and Bact. 44:517-548, 1937. 



2. Curtis, M. R.: The ligaments of the oviduct of the domestic fowl. Maine 



Agr. Expt. Sta. Bui. 176, 1910. 



3. Curtis, M. R.: The frequency of occurrence of tumors in the domestic 



fowl. Jour. Agr. Res. 5:397-404, 1915-16. 



4. Eber, A., and Ma'ke, E.: Geschwiilstbildungen beim Hausgefliigel. Ztschr. 



f. Krebsforsch. 36:178-192, 1932. 



5. Ewing, J.: Neoplastic diseases. Philadelphia, VV. B. Saunders Company, 



Third Edition, 1934, 1127 pp. 



6. Feldman, W. H.: Thymoma in a chicken (Callus domesticus). Amer. 



Jour. Cancer 26:576-580, 1936. 



7. Feldman, W. H.: Neoplasms of domesticated animals. Philadelphia, W. B. 



Saunders Company, 1932, 410 pp. 



8. Feldman, W. H., and Olson C: The pathology of spontaneous leukosis of 



chickens. x\mer. Vet. Med. Assoc. Jour. 82:875-900, 1933. 



9. Feldman, W. H., and Olson C: Keratinizing embryonal nephroma of the 



kidneys of the chicken. Amer. Jour. Cancer 19:47-55, 1933. 



10. Friedgood, H. B., and Uotila, U. U.: Occurrence of ovarian "tumors" in 



spontaneous virilism of the hen. Endrocrinology 29:47-58, 1941. 



11. Goss, L. J.: The incidence and classification of avian tumors. Cornell 



Vet. 30:75-88, 1940. 



12. Heim, Fr.: Huhnergeschwulste. Ztschr. f. Krebsforsch. 33:76-125, 193i. 



