Resumo
Background: Endocrine tumors are considered rare in veterinary medicine. Studies suggest that only one or two per cent of these are primary neoplasms of the adrenal glands. Concerning the histological classification of these masses, the most frequently occurring malignant neoplasms in dogs are adenocarcinomas and pheochromocytomas and, among the benign tumors, adenomas are the most common. Although much rarer, hemangiomas, myelolipomas, among others, may also occur. Dogs with this kind of neoplasm could be asyntomatic or show gastrointestinal signs, pain and urinary tract infection. Adrenalectomy is the treatment of choice and could be curative in most cases. This paper reports a case of two concurrent benign, rare adrenal neoplasms in a dog, emphasizing the clinical signs, diagnosis and treatment. Case: An eight-year-old, male castrated Chow-chow, weighting twenty one kilograms, was admitted at the Veterinary Teaching Hospital of the Federal University of Rio Grande do Sul (UFRGS) with a history of intermittent vomiting and diarrhea since it was a puppy. Because of the chronicity and nonspecific signs, additional tests were requested. Abdominal ultrasonography showed a round mass, measuring approximately 3.7 cm x 3.2 cm, suggesting a neoplasm. Blood pressure was measured and the mean value was 152 mmHg. Laboratory tests included a complete blood count, albumin (31.62 g/L), alanine aminotransferase (26.19 U/L), alkaline phosphatase (64.68 U/L), sodium (147 mmoL), potassium (4.5 mEq/L), fasting blood glucose (60.87 mg/dL), cholesterol (137.64 mg/dL), triglycerides (34.89 mg/dL), amylase (592 U/L), lipase (163 U/L), creatinine (0.67 mg/dL), and parasitologic exam of the feaces, which revealed no significant changes at all. An unilateral adrenalectomy was performed for diagnostic and therapeutic purposes. The patient was anesthetized and was placed in left lateral recumbency. An incision was made along the thirteenth rib, allowing an adequate visualization of the right adrenal. A careful dissection and ligation of vessels was performed, the gland was removed and sent for histopathology. The abdominal cavity was sutured routinely. Histopathological examination disclosed two fragments of benign tumors, namely myelolipoma and hemangioma. The animal had an excellent postoperative recovery, being given antibiotics, analgesics and daily dressings as treatment. In the follow-up reexamination only mucus persisted in the stool, however a diagnostic colonoscopy was not authorized by the owner. Discussion: Adrenalectomy represented both the definitive diagnostic and therapeutic methods of choice, since the growth of these masses could compromise adjacent organs. The open approach is the method used for adrenalectomy in veterinary patients, as opposed to people, where the laparoscopic surgery is generally chosen. In this report, we opted for an right paracostal incision to allow a better exposure and dissection of the adrenal gland in this medium-sized dog. There was no need for supplemental glucocorticoids in the postoperative period because these neoplasms are non-functioning, which represents a contraindication for its use. Therefore, total adrenalectomy was proven effective in the treatment of these two concurrent adrenal neoplasms, as supported by the postoperative course.