Leiomyosarcoma associated with acute abdomen and uterine torsion in a white-collared peccary (Tayassu tajacu)

Abstract

ABSTRACT: This study aimed to report a leiomyosarcoma associated with acute abdomen and uterine torsion in an 8-year-old, nulliparous, white-collared peccary (Tayassu tajacu) kept under human care. The animal presented a two-day clinical history of abdominal bulging, vaginal discharge, and acute abdomen. Ultrasound findings indicated an intrabdominal tumor, and an exploratory laparotomy followed by an emergency ovariohysterectomy was performed to remove the tumor. Grossly, the right horn exhibited a firm, friable tumor measuring 23cm in diameter and weighing 9.3kg. On the cut surface, the tumor drained a foul-smelling fluid and bloody content. The tumor wall was 6cm thick, dark red, firm, and had a brittle, soft, yellow fibrillar material firmly adhered to its surface. Microscopically, the lesion consisted of malignant proliferation of leiomyocytes with necrosis and hemorrhage of the endometrium and myometrium. The cytoplasm of the neoplastic cells was strongly immunopositive for vimentin and smooth muscle actin but negative for cytokeratin and desmin. Leiomyosarcoma is uncommon in Tayassuidae, and its clinicopathological presentation may be concomitant with acute abdomen, uterine torsion, and pyometra. These conditions should be included in the differential diagnosis of reproductive diseases observed in female peccaries.

Keywords

• Leiomyosarcoma
• uterine neoplasia
• sepsis
• smooth muscle actin
• white-collared peccary
• Tayassu tajacu