Features of the tumor are characteristic of the inverted papilloma. The tumor was surgically excised.

Histology

Polypoid tissue covered with columnar epithelium with goblet cells, which showed inversion into the underlying connective tissue stroma.

Diagnosis: inverted papilloma

Discussion

Atrophy of cerebellum and brainstem, with hot cross bun sign of the pons raises the possibility of multiple system atrophy (MSA-C) although other neurodegenerative diseases can have a similar appearance. 

Patient's symptoms connected with the MSA-C from the medical history and clinical examination: ataxia and dysarthria. Unfortunately, the patient hasn't had any further exams in our hospital.