Olfactory Neuroblastoma: A case report of a rare tumor and a brief review of the literature

Olfactory neuroblastoma (ONB) is a rare neoplasm originating from the olfactory neuroepithelium. Due to its rarity and diagnostic challenge, it requires a multidisciplinary diagnostic and management approach. Our patient is a 49-year-old male with no previous history of malignancy who presented with recurrent epistaxis, diplopia, facial edema, anosmia, and a protruding mass from his right nostril. Imaging studies showed a heterogeneously enhancing mass (4.2 x 3.5 x 3.8 cm) in the right superior nasal cavity extending through the skull base and causing displacement of the right frontal lobe. A multidisciplinary tumor board discussion led to an endoscopic biopsy of the tumor before proceeding with chemotherapy, transcranial resection of the tumor, and postoperative radiation. Pathology results indicated the tumor was positive for synaptophysin, chromogranin, NSE, and S100 and negative for cytokeratin, EMA, LCA, desmin, and myogenin, confirming a grade II ONB without lymphovascular invasion. The patient had no evidence of tumor recurrence at 36 months of follow-up. He continues to have hyposmia, frontal headaches, and right eye epiphora from nasolacrimal duct injury, which have all been managed conservatively. Overall, the patient has a good functional status and intact cognitive abilities following tumor resection. This case highlights the importance of recognizing variable presentations of rare tumors, especially in patients with low-risk factors, and of appropriately managing them to achieve optimal patient outcomes.