Standing Hand-Assisted Laparoscopic Diagnosis and Treatment of a Rare Case of Uterine Adenocarcinoma in an 18-Year-Old Mare.

An 18-year-old French Trotter mare was presented to the Clinique Equine, Ecole Nationale Vétérinaire d'Alfort, for exploration of a 3-month-duration vaginal bleeding. A transrectal ultrasound examination identified a mass within the right uterine horn wall, which had been suspected during transrectal palpation. It was described as a firm heterogeneous intramural mass (7 × 12 cm) in the right uterine horn, located few centimeters cranially to the bifurcation. Hysteroscopy confirmed the ulcerated and irregular shape of the mass. A standing hand-assisted flank laparoscopy was performed to carry out a partial ovariohysterectomy. Two days after surgery, the mare presented with acute and severe signs of colic and was euthanized. Postmortem examination revealed a 720° small intestine volvulus at the mesenteric root, a left dorsal displacement of the large colon, and iliac and tracheobronchial lymph node hypertrophy. Histopathological examination of the removed uterine mass revealed a well-differentiated and infiltrating uterine adenocarcinoma, with lymph node metastasis. Uterine neoplasia, especially adenocarcinoma, is uncommon in the mare and can be successfully removed using a standing hand-assisted laparoscopic technique, which avoids the risks associated with general anesthesia and allows a histologic diagnosis of malignancy. In such cases, though, initial staging and identification of metastasis remain a challenge that will influence the treatment strategy.