Abstract
BACKGROUND: Case reports of primary squamous cell carcinoma (SCC) of the esophagus in cats are limited, and it is considered necessary to accumulate more cases. CASE DESCRIPTION: An 8-year-old spayed female Japanese domestic cat presented with complaints of regurgitation and weight loss for the previous 2 months. A radiographic examination showed that the contrast agent used in the esophagography performed in another veterinary hospital remained inside the esophagus, and a mass lesion on the cranial side of the diaphragm was suspected. Computed tomography examination revealed a mass lesion originating from the caudal esophagus. Esophageal endoscopy revealed a bulging mass in the esophageal mucosa, which was diagnosed by tissue biopsy as SCC. Because hepatic lipidosis was suspected based on CT images, a gastrostomy tube was placed through laparotomy to improve food intake. However, after the gastrostomy tube placement, the blood bilirubin and ammonia concentrations markedly increased, and the cat died 2 days later. Postmortem histopathological examination revealed that the esophageal SCC had invaded the gastric cardia's mucosal and muscular layers. Metastatic lesions were also confirmed in the lymph nodes around the liver. The liver histopathology was compatible with severe hepatic lipidosis, and liver failure was considered the cause of death. CONCLUSION: Although primary SCC of the esophagus in cats is considered a rare disease, it should be considered as a differential diagnosis in patients with severe regurgitation and weight loss. When treating cats with long-term starvation, the progression of potentially fatal hepatic lipidosis should be considered.