Common signs and symptoms of olfactory neuroblastoma include unilateral nasal obstruction, nasal discharge, epistaxis, anosmia, frontal headaches, and eustachian tube dysfunction. Patients may also present with vision loss, orbital pain, proptosis, or ophthalmoplegia due to tumor involvement of the orbit. On physical exam, a polypoid mass is often seen in the nasal cavity. As the initial signs and symptoms of olfactory neuroblastoma are similar to those of other common rhinologic diseases, olfactory neuroblastoma may progress significantly before diagnosis. The tumor is locally invasive to the paranasal sinuses, orbit, and the central nervous system. There is a predilection for early metastases to the cervical lymph nodes, most frequently to level II. Tumors metastatic to regional lymph nodes or distant areas portend a worse prognosis than tumors confined to the nasal cavity.
Multiple staging systems exist for olfactory neuroblastoma, but the most commonly used is the modified Kadish staging system:
- Stage A – tumors with sinonasal involvement only
- Stage B – tumors with paranasal sinus extension
- Stage C – tumors with extra-sinus extension
- Stage D – metastatic disease
Olfactory neuroblastoma may also be given a histologic grade using the Hyams grading system. This grading system is divided into grades I through IV (most differentiated to least differentiated) and is based on tumor architecture, presence of mitotic activity, nuclear pleomorphism, neurofibrillary matrix, Homer Wright pseudorosettes, glands, calcification, and necrosis. Some studies have shown worse survival prognosis with Hyams grade III and IV tumors.
C30.0 – Malignant neoplasm of nasal cavity
422886007 – Olfactory neuroblastoma
- Small round blue cell tumors: sinonasal undifferentiated carcinoma, squamous cell carcinoma, sinonasal malignant melanoma, small cell undifferentiated (neuroendocrine) carcinoma, Ewing sarcoma, rhabdomyosarcoma, small cell osteosarcoma, synovial sarcoma, natural killer / T-cell lymphoma, extramedullary plasmacytoma. Use biopsy and histologic evaluation with ancillary testing such as immunohistochemistry, flow cytometry, or fluorescence in situ hybridization (FISH) tests.
- Other sinonasal tumors: squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma, nasopharyngeal carcinoma, osteosarcoma, chondrosarcoma, inverted papilloma, pituitary adenoma
- Dermoid cyst
- Inflammatory polyps
- Allergic fungal sinusitis