German Shepherd Case

Species: Canine
Breed: German Shepherd
Age: 11yrs
Gender: Female Spayed

Source/History:

Overall the dog has been normal except for leaking some urine with blood the past 2 months. Cystocentesis: urine sample was normal. Discovered this growth while performing digital exam of the vulva / vagina. There was mild to moderate pain, surgically removed. Visually couldn’t determine if good margins obtained as it was a blended with normal tissue. 1 cm firm, red, ulcerated, oval growth located on the floor of the vagina in between the urethral papilla and vulvar opening.

 

Click here for the IDEXX Pathology Report on this case.

Microscopic Description:

This section of vagina is characterized by islands of neoplastic epithelial structures within the vaginal stratified squamous epithelium. The neoplastic structures form vague acini lined by cuboidal to polygonal epithelial cells. Numerous foci of these cells are present in dilated lymphatic vessels in the submucosa. Neoplastic cells have moderate to marked anisocytosis and anisokaryosis. The cells have eosinophilic cytoplasm and an oval to round nucleus with a coarsely clumped chromatin pattern. Mitotic figures are infrequently observed. Individual cell necrosis is present. Neoplastic tissue extends to the margins. Accumulations of large lymphoid follicular structures are present in the superficial subepithelial tissue.

Microscopic Interpretation:

Interpretation:  Vagina: Urothelial (transitional cell) carcinoma

Mitotic Count: 2

Excision: Extends to surgical margins

Vascular Invasion: Observed Frequently

Comments:

Transitional cell carcinomas of the urinary bladder have a variable prognosis depending on the extent of mural invasion, degree of tumor differentiation, degree of associated desmoplastic response, and the length of time the tumor has been present. In general, tumors that are limited to the mucosa (papillary or in situ growth pattern) have a better prognosis than those that invade deeper portions of the bladder wall. All transitional cell carcinomas have at least moderate potential for metastasis to regional lymph nodes and distant sites including the lungs. Highly invasive tumors can extend through the wall and directly into the adjacent peritoneal cavity. Approximately 50% of these tumors eventually metastasize. Distant metastasis occurs more frequently with increasing duration of the tumor.

Please note, this is an unusual presentation of urothelial (transitional cell) carcinoma (TCC). I could not find information on vaginal urothelial cell tumors in bitches but did find some information in the literature regarding human patients. The pathogenesis of vaginal TCC is unknown at this time. It is hypothesized that the tumor may have developed in the bladder or bladder neck of the patient of this report with local invasion into the anterior vaginal wall. Metastatic spread through lymphatic vessels is also possible (especially in this case as tumor is easily identified in lymphatic vessels). In the human patient, a radical anterior pelvicectomy and bilateral pelvic and inguinal lymph node dissection was performed.

References:

Tumors in Domestic Animals, 4th ed., pp 529-535, 2002; J Comp Path, 1995;113:113-130.
Fouad Aoun, Hampig Raphael Kourie, Elie El Rassy, and Roland van Velthoven.Bladder and vaginal transitional cell carcinoma: A case report. Oncol Lett. 2016 Sep; 12(3): 2181–2183.

Image Notes:

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