Introduction

Ovarian teratoma is a rare neoplasm in domestic animals. It is characterized by the presence of extraovarian tissue, such as bone and teeth. Ovarian teratoma has a low metastatic potential.

Objective

To describe a case of malignant teratoma with distant metastatic focus in a 3-year-old mongrel bitch.

Method

A 3-year-old mongrel bitch was treated at the Veterinary Hospital of São Paulo State University, Jaboticabal, Brazil, presenting bloody vaginal discharge. At ultrasonography a heterogeneous structure was visualized with cystic formations in right ovary topography. Blood count, serum ALT, and creatinine were performed at the preoperative examination. The animal was subjected to the surgical procedure.

Results

During surgical procedure presence of a mass in the right ovary was noted, with changes of regional lymph nodes and omentum. Material was collected for histopathology. A week after surgery the animal returned, with anorexia, dyschezia, and dysuria. Supportive therapy was instituted. After 15 days of surgery, the animal showed severe anorexia, dyspnea, abdominal distention, with the presence of abdominal and pleural effusion. The results of the histopathology suggested infiltrative malignant teratoma with metastasis in lymph nodes. The animal underwent exploratory laparotomy which showed presence of metastatic foci in bowel, liver, and right kidney. The animal died during surgery.

Conclusion

There are few studies on the metastatic potential of ovarian teratomas, making it difficult to elect a suitable protocol, since in most cases it is necessary to extrapolate data from human medicine. In this case there was not enough for it to be established chemotherapeutic therapy.