Olfactory neuroblastoma: literature review and presentation of two clinical cases with different tumour infiltrations and different approaches.

The olfactory neuroblastoma is a rare malignant neoplasm derived from the olfactory neuroepithelium. It can metastasize to cervical lymph node chains and distant organs through hematogenous or lymphatic routes. Two clinical cases are presented: the first, a 56-year-old man with no pathological history, exhibited symptoms evolving over 2 months, characterized by persistent rhinorrhea with frequent epistaxis, ipsilateral proptosis, left hemicranial pain, anosmia, and dysgeusia. Radiological images showed involvement of paranasal sinuses, left orbital cavity, and intracranial region. The second case involved a 46-year-old male with progressive symptoms over more than 1 year, including nasal obstruction, rhinorrhea, self-limited epistaxis, anosmia, weight loss in the last 3 months, and subjective decrease in visual acuity. A protruding mass in the left nasal fossa was observed without intracranial involvement. Both cases were pathologically and immunohistochemically consistent with olfactory neuroblastoma, Hyams grade 2.