A leiomyoma is an uncommon benign tumor arising from smooth muscle in cats. They are seen most commonly in the gastrointestinal tract, however can be seen in association with the vagina and/or uterus.
There are no specific causes for leiomyomas, and they are seen most commonly in middle-aged to older dogs and cats. Dogs are more commonly affected than cats.
What to Watch For
Borborygmus (noise from the gastrointestinal tract)
Tenesmus (straining to defecate)
Weakness associated with hypoglycemia (low blood sugar)
Leiomyomas associated with the genital tract are most often found as incidental findings, and are on rare occasion associated with vaginal discharge.
Diagnosis of Leiomyoma in Cats
Baseline tests, including a complete blood count (CBC), biochemical profile, and urinalysis, are usually within normal limits, although hypoglycemia is not uncommon.
Abdominal radiographs (x-rays) may support thickening or a mass in the gastrointestinal tract or simply rule out other disorders.
Abdominal ultrasound may reveal a thickening or mass in the intestinal tract or rule out other disorders. For those tumors associated with the uterus, there may be visible changes.
Upper gastrointestinal contrast radiography (dye study) may reveal a thickening or a mass in the esophagus, stomach, or small intestine.
Endoscopy of the upper and/or lower bowel may be of benefit in some cases, although it may not sample tissue deep enough to support a definitive diagnosis.
Abdominal exploratory and biopsy of thickened tissue or mass lesions is the only definitive means of diagnosing a leiomyoma.
Treatment of Leiomyoma in Cats
Surgical resection (removal) is the treatment of choice. It is curative if the tumor is able to be resected.
Surgical debulking (removing as much as possible) may help improve clinical signs.
Dietary manipulation may be of benefit, to include feeding small, frequent, easily digestible meals.
Home Care and Prevention
It is very important to follow the instructions given to you by your veterinarian. If your pet has a recurrence of signs, contact your veterinarian at once. Prognosis varies depending on the location, size, and ability to remove the tumor surgically.
There is no known prevention of most leiomyomas. Ovariohysterectomy (spay) will prevent the formation of uterine leiomyomas.