Combination of a Teratoma and Embryonal Carcinoma of the Testis in SD IGS Rats: A Report of Two Cases

Abstract

Testicular tumors of germ cell origin are extremely rare in rats. We encountered 2 cases of teratoma and embryonal carcinoma in the testes of 8- and 10-week-old Sprague-Dawley IGS rats. A unilateral tumor mass with bilateral testicular atrophy was observed macroscopically in both cases. Microscopic examination revealed that the tumor mass had characteristic features of a teratoma and was composed of several types of differentiated cells and tissues at various stages of maturation. Embryonal carcinoma tissue, composed of undifferentiated cells with an embryonic and anaplastic appearance, was observed within the tumor mass. In addition, foci of intratubular teratomas and embryonal carcinomas were observed in the testis on the side without any obvious mass. No obvious germ cells were observed in the seminiferous tubules in the remnant nontumorous area. Furthermore, intratubular transition of cells was observed from the embryonal carcinoma tissue to the squamous epithelium. This finding indicates that an embryonal carcinoma differentiates toward a teratoma even at a very early stage of development of the germ cell tumor.

Keywords

Teratoma embryonal carcinoma teratocarcinoma germ cell tumor testis rats

References

Göbel U. , Calaminus G. , Engert J. , Kaatsch P. , Gadner H. , Bökkerink Jpm , Haas RJ , Waag K. , Blohm Meg , Dipert S. , Teske C. , Harms D. (1998). Teratomas in infancy and childhood. Med Pediatr Oncol 31: 8-15.

Itoh T. , Shirota K. , Kagiyama N. (1985). Spontaneous teratoma in a Sprague-Dawley rat. Exp Anim 34: 207—209.

Maekawa A. (1990). Tumors of the ovary. In: Pathology of Tumours in Laboratory Animals, Vol 1, Tumours of the Rat, 2nd ed, Turusov VS , Mohr U (eds). IARC, Lyon, France, pp 473-497.

Maekawa A. , Onodera H. , Furuta K. , Tanigawa H. , Nagaoka T. , Todate A. , Matsushima Y. , Ogiu T. ( 1989). Teratoma of the pituitary gland in a young male rat. J Comp Pathol 100: 349-352.

Mark SD , Gowland SP , Arnold EP , McRae CU , Fitzharris BM (1994). Carcinoma in situ of the testis followed by an overt malignant teratoma of the testis within 12 months. Aust NZ J Surg 64: 862-864.

Mostofi FK , Price EB (1973). Germ cell tumors showing one histologic pattern . In: Tumors of the Male Genital System, Mostofi FK , Price EB (eds). AFIP, Washington, DC, pp 21-67.

Mostofi FK , Price EB (1973). Germ cell tumors showing more than one histologic pattern. In: Tumors of the Male Genital System, Mostofi FK , Price EB (eds). AFIP, Washington, DC, pp 68-84.

Mostofi FK , Sesterhenn IA , Bresler VM (1990). Tumors of the testis. In: Pathology of Tumours in Laboratory Animals, Vol 1, Tumours of the Rat, 2nd ed, Turusov VS , Mohr U (eds). IARC, Lyon, France, pp 399-415.

Mostofi FK (1983). Pathology of germ cell tumors of testis. A progress report. Cancer 45: 1735-1754.

10.

Ninomiya H. (1983). Spontaneous teratoma in a Wistar rat. Exp Anim 32: 145-149.

11.

⊘sterlind A. , Berthelsen JG , Abildgaard N. , Hansen SO , Jensen H. , Johansen B. , Munck-Hansen J. , Rasmussen LH (1987). Incidence of bilateral testicular germ cell cancer in Denmark, 1960-84: Preliminary findings. Int J Androl 10: 203-208.

12.

Reindel J. , Bobrowski W. , Gouch A. , Anderson J. (1996). Malignant intracranial teratoma in a juvenile Wistar rat. Vet Pathol 33: 462-465.

13.

Schardein JL , Fitzgerald JE (1976). Teratoma in a Wistar rat. Lab Anim Sci 27: 114.

14.

Skakkebaek NE (1978). Carcinoma in situ of the testis: Frequency and relationship to invasive germ cell tumours in infertile men. Histopathology 2: 157-170.

15.

Stevens LC (1957). A description of spontaneous congenital testicular teratomas in strain 129 mice. J Natl Cancer Inst 18: 719-747.

16.

Stevens LC (1959). Embryology of testicular teratomas of strain 129 mice. J Natl Cancer Inst 20: 1257-1276.

17.

Stevens LC (1962). Testicular teratomas in fetal mice. J Natl Cancer Inst 28: 247-268.

18.

Stevens LC , Little CC (1954). Spontaneous testicular teratomas in an inbred strain of mouse. Proc Natl Acad Sci USA 40: 1080-1087.

19.

Wheeler JE , Rudy FR ( 1990). The testis, paratesticular structures, and male external genitalia. In: Principles and Practice of Surgical Pathology , 2nd ed, Silverberg SG (ed). Churchill Livingstone Inc, Edinburgh, United Kingdom, pp 1531-1585.