Page 1380 - Clinical Small Animal Internal Medicine

1318 Section 11 Oncologic Disease

metastatic rate (up to 50%). Definitive diagnosis Feline vaginal tumors are extremely rare, with most
VetBooks.ir requires histology and is easily obtained at the time of being benign.
hysterectomy.

Therapy Epidemiology
In dogs, there is some evidence that vaginal neoplasia
Ovariohysterectomy is the treatment of choice in all may be associated with a history of mammary tumors,
cases of uterine tumors, except in the setting of distant ovarian cysts, pyometra or previous treatment with
metastasis or carcinomatosis. Surgical excision of any reproductive hormones. One study found that the
regional metastatic foci is also recommended. majority of dogs with vaginal cancer are sexually intact
In women, adjunctive chemotherapy has been shown and nulliparous.
to have a mild to modest benefit for metastatic leiomyo-
sarcomas and carcinosarcomas when compared to sur- Signalment
gery or radiation alone. Although there are no veterinary
reports on the use of chemotherapy for uterine tumors, The mean age for dogs with vaginal cancer is 10.8 years.
it is highly recommended in cases of malignant or Although there is no breed predilection, both boxers and
metastatic tumors. Based on human data, it would be poodles have been reported to have an increased risk.
reasonable to consider chemotherapeutics such as cispl-
atin, carboplatin, doxorubicin, cyclophosphamide, gem- History and Clinical Signs
citabine, and ifosfamide as viable therapeutic options.
A 2007 study evaluated the presence of estrogen and Common clinical signs reported include purulent to
progresterone receptors in smooth muscle genital hemorrhagic vaginal discharge, swelling of the vulva or
tumors. Estrogen receptor alpha (ERalpha) was found in perineal region, a vulvar mass, constant licking of the
56.3% and progesterone receptor (PR) in 84.4% of canine vulva, dysuria or tenesmus. Tumors typically arise from
tumors. This finding makes hormone receptor antago- the vulva, vestibule, or vaginal roof. There is no correla-
nist therapy a reasonable treatment option. tion between the location of the mass and histologic
tumor type.
Prognosis
Diagnosis
The prognosis is excellent for dogs and cats with benign
tumors following complete ovariohysterectomy. For Definitive diagnosis of malignancy requires histology.
malignant tumors localized to the uterus, the prognosis However, the presence of a vaginal mass is often easily
can be good as many of these dogs can still be cured with determined based on history, clinical signs, and physical
surgery. However, the prognosis is guarded for meta- exam findings (including a digital vaginal exam). For
static tumors. In cats with uterine adenocarcinomas, the small lesions, vaginoscopy may be required. Full staging
prognosis is guarded to poor as they often metastasize. is recommended for all animals with vaginal tumors:
complete blood count, biochemistry, three‐view thoracic
radiographs, and an abdominal ultrasound. Paraneoplastic
Vaginal Tumors hypercalcemia has been infrequently reported to be
associated with older basset hounds with clitoral
adenocarcinoma.
Etiology/Pathophysiology
Vaginal tumors are the second most common tumor of Treatment
the female reproductive system. The most common
histologic type is leiomyoma. These tumors, similar to Surgical excision with dorsal episiotomy is the treat-
the uterine leiomyomas, are slow growing and do not ment of choice. Concurrent ovariohysterectomy is also
metastasize. Other less common tumors include fibroma, recommended as some malignancies such as leiomyo-
polyp, lipoma, myxoma, lymphoma, liposarcoma, mast mas may be hormone dependent. For highly invasive
cell tumor, adenocarcinoma, squamous cell carcinoma, vaginal tumors, either subtotal vaginectomy or a com-
fibrosarcoma, leiomyosarcoma, osteosarcoma, heman- plete vulvovaginectomy and perineal urethrostomy
giosarcoma, and TVT. can be performed. It is advised that any metastatic foci
One study found that all pedunculated masses were should be removed at the same time.
benign. And of the sessile, broad‐based masses, all were Adjunctive radiation therapy and chemotherapy can
malignant (with the majority being TVT). be considered for animals that have incompletely excised