Dental corner: Lingual squamous cell carcinoma

An 11-year-old spayed female Chesapeake Bay retriever was presented to the University of Pennsylvania's Dentistry and Oral Surgery Service because of a mass on her tongue. The owners had noticed what they thought was a blister on the dog's tongue, and the referring veterinarian had biopsied the mass. The histopathologic results were squamous cell carcinoma. The lymph nodes were not enlarged, and three-view thoracic radiographs showed no evidence of metastasis.

Squamous cell carcinoma is the second most common malignant tumor reported in dogs.1 It can occur anywhere, but it often affects the tonsils or tongue. Early surgical intervention is ideal but requires large margins—up to 3 cm. Because the tumor was located on the middle or body of the tongue, it was thought that surgery was a viable option.

About 80 percent of the tongue was resected. An esophagostomy tube was placed to provide nutrition and medications postoperatively. A fentanyl patch was placed on the dog's chest to provide analgesia. The incision site seeped periodically for several days, but the patient was bright and alert and was sent home with antibiotics and detailed feeding instructions. She wore an Elizabethan collar for two weeks after the surgery and continued to do well at home, eventually re-learning how to eat and drink water. The owners had to make tiny meatballs and hold them at an incline so the dog could swallow them. It took several weeks, but she learned how to suck up water instead of lapping it up with her tongue. The esophagostomy tube was removed after six weeks.

At her one-year recheck, there was no evidence of metastasis, the lymph nodes were of normal size, and the chest radiographs were clean. The doctors were concerned about her ability to regulate her temperature in the summer months because of her inability to pant, but the owners were diligent about keeping her cool at all times. She still has the base of her tongue and drools more than usual, but otherwise she leads a happy, healthy life.

Patricia March is a technician at Animal Dental Center in Baltimore, Md., and the current president of the Academy of Veterinary Dental Technicians (AVDT).

Reference

1. Withrow SJ, Vail D. Withrow and MacEwen's small animal clinical oncology, 4th ed. St. Louis, Mo.: Saunders-Elsevier, 2007;455,457.