A Massive Adenoma of the Uterine Tube in a Young Intact Female Dog: Surgical Intervention and Outcome

Abstract

Tumors originating from the uterine tube are exceedingly rare in dogs, with limited clinical and therapeutic data available. This report illustrates a case of a uterine tube adenoma in a one-year-and-two-month-old intact female Pomeranian presented with severe abdominal distension. Diagnostic imaging revealed a large abdominal mass compressing the left kidney, suspected to originate from the female reproductive organs. Surgical excision of the mass, accompanied by ovariohysterectomy, was performed without complications. The tumor, measuring 30 cm in diameter and weighing 1.086 kg, accounted for 28% of the dog's body weight. Histopathology confirmed the diagnosis of benign uterine tube adenoma with no evidence of vascular invasion. The dog experienced no postoperative complications and remained tumor-free for over 912 days post-surgery. This case highlights the possibility of uterine tube tumors developing even at a young age and reaching significant sizes without overt clinical signs. While diagnostic findings were unable to identify the precise tissue origin, surgical excision was an effective treatment, even for this large-sized tumor. The findings of this case underscore the importance of including uterine tube tumors in differential diagnoses for female reproductive mass lesions. Further case accumulation is necessary to expand our understanding of this rare condition in dogs.

Keywords: adenoma; dog; fallopian tube; neoplasia; oviduct.

Figure 1

Abdominal radiographs: (A) right lateral recumbency image and (B) ventrodorsal image revealing a mass in the left abdominal region with displacement of the small intestine to the right.

Figure 2

Preoperative abdominal ultrasound imaging. (A) Homogenous parenchymal area of the mass. (B) Cystic area with anechoic region. (C) Color Doppler imaging of parenchymal areas revealing relatively poor vascularity. (D) Color Doppler imaging of cystic area revealing abundant blood flow.

Figure 3

Intraoperative photographs. (A) The left uterine horn (arrowheads) was continuous from the mass (arrows). (B) Resected mass. The mass had a region exhibiting red in color, with soft consistency, and a folded surface (arrowhead), as well as solid area that was enveloped by a capsule (arrow). (C) Many white to red nodules (arrowheads) were seen on the parietal peritoneum.

Figure 4

Histopathological findings stained with hematoxylin and eosin stain. (A) Photomicrograph of the mass (sub-gross picture). The mass is composed of tubular and papillary proliferation of tumor cells. Bar = 1000 μm. (B) Photomicrograph of the mass (high-power field). Tall columnar epithelial cells have cilia on their apical surface (arrows). No atypia is noted. Bar = 50 μm. (C) Photomicrograph of the contralateral normal uterine tube (high-power field). The epithelial cells are tall columnar and ciliated (arrows). Bar = 50 μm.