Clitoral adenocarcinoma

From Dog
Macroscopic appearance of a clitoral adenocarcinoma in a dog[1]

Clitoral adenocarcinoma are a rare malignant tumor of the canine clitoris.

In dogs, the majority of reported vaginal and vulvar tumors are benign and occur in intact females, but malignant tumors are more common in spayed females[2].

These tumors, which develop on the epithelial lining of the clitoris, can occur in ovariohysterectomized dogs and there development may well be independent of hormonal regulation.

Clitoral adenocarcinoma can develop into relatively large masses which can be visible on examination of the vulva[1], with vulvar pruritus and self-induced dermatitis.

Affected dogs frequently display signs of dysuria, which is often referable to genital pain.

Blood tests in advanced cases often show paraneoplastic hypercalcemia.

A presumptive diagnosis can be established on visual examination, but abdominal and thoracic imaging with ultrasonography, radiographs and CT are warranted to exclude metastases.

A definitive diagnosis is established on histological examination of biopsied material taken under sedation or general anesthesia.

A differential diagnosis include transmissible venereal tumor, leiomyosarcoma, mast cell tumor, squamous cell carcinoma, hemangiosarcoma and vaginal hyperplasia as well as other causes of hypercalcemia such as anal sac adenocarcinoma[3].

These tumors in humans are often refractory to chemotherapy and radiation therapy and clitoridectomy may only afford a temporary cure[4].

Advanced cases often develop regional and iliac lymphadenopathy associated with metastases.

References

  1. 1.0 1.1 Neihaus SA et al (2010) Primary clitoral adenocarcinoma with secondary hypercalcemia of malignancy in a dog. J Am Anim Hosp Assoc 46(3):193-196
  2. Brodey RS & Roszel JF (1967) Neoplasms of the canine uterus, vagina and vulva: a clinicopathologic survey of 90 cases. J Am Vet Med Assoc 151:1294-1307
  3. Thacher C & Bradley RL (1983) Vulvar and vaginal tumors in the dog: a retrospective study. J Am Vet Med Assoc 183:690-692
  4. Wagner W et al (1999) Vulvar carcinoma: a retrospective analysis of 80 patients. Arch Gynecol Obstet 262(3-4):99-104