Secondary brain tumor caused by infiltration of nasal neuroendocrine carcinoma in a chihuahua dog: Clinical, magnetic resonance imaging and histopathological findings

Abstract

A 14-year-old neutered female Chihuahua was presented because of seizure episodes and circling to the left side. Based on neurological examination, the lesion was localized on left forebrain. The mass in the left nasal cavity and breaching of the nasal septum were seen magnetic resonance images. And there was a presence of contrast enhanced mass involving the rostral left brain. Based on diagnostic image analysis, this lesion strongly suggested secondary brain tumor infiltrated by nasal cavity. The patient's symptoms were well controlled by a combination therapy of prednisolone and lomustine (CCNU), and survived for two months after diagnosis. This case was definitively diagnosed as a nasal neuroendocrine carcinoma based on histopathological findings. This report describes the clinical findings, imaging characteristics, and pathologic features of secondary brain tumor which caused by infiltration of nasal neuroendocrine carcinoma in a dog.