Malignant Oestrogen-producing Teratoma in a Cat

Pathology in Practice

“…4 Intracranial 11 and testicular teratomas 12 have also been reported in South American cervids. For the deer of the present report, FNA biopsy proved useful in presumptively diagnosing the neoplasm, and the immunostaining profile observed confirmed the predominance of a mature, mixed epithelial-mesenchymal composition of the tumor mass, similar to that reported in other animal species 11,13,14 and humans. 15,16 The embryogenic mechanisms involved in the development of renal teratomas remain unknown; however, the proximity between the nephrogenic cord and gonadal ridge combined with failures in cell migration may justify the displacement of germ cells within the kidney.…”

Case report: Mature extragonadal teratoma at the proximal part of the tail in a kitten

“…Extragonadal teratomas are exceedingly rare, but have been reported in a variety of wildlife and domestic animals including ferrets ( 13 ), a juvenile Wistar rat ( 14 ), a dog ( 15 ) and domestic avian species such as a lesser kestrel ( Falco naumanni ) ( 16 ). In cats, gonadal teratomas including ovarian and testicular teratomas were unilateral and occurred at an age ranging from 5 months to 17 years ( 5 , 6 , 17 , 18 ). Among these studies, mature teratomas had benign behavior and were curative after ovariohysterectomy ( 17 , 18 ), while immature teratomas reported in two cats had malignant behavior with intra-abdominal metastasis and the ability to secrete estrogen ( 5 , 6 ).…”

“…In cats, gonadal teratomas including ovarian and testicular teratomas were unilateral and occurred at an age ranging from 5 months to 17 years ( 5 , 6 , 17 , 18 ). Among these studies, mature teratomas had benign behavior and were curative after ovariohysterectomy ( 17 , 18 ), while immature teratomas reported in two cats had malignant behavior with intra-abdominal metastasis and the ability to secrete estrogen ( 5 , 6 ).…”

“…Based on the histomorphology, it can be subdivided into immature and mature variants, depending on the degrees of differentiation of neoplastic components toward normal tissue structures. Most mature tumors are benign, and surgical excision with a clear margin is usually curative ( 2 ), while neoplasms with immature components can be malignant with metastatic potential ( 5 , 6 ). In the present case, we reported a case of a mature extragonadal teratoma in a male kitten with a clinical outcome after treatment along with a brief review.…”