<unk> , also known as olfactory neuroblastoma, is a rare form of cancer involving nasal cavity and believed to arise from the olfactory epithelium. It can cause loss of vision, and taste.<unk> s are undifferentiated tumors of neuroectodermal origin derived from the olfactory epithelium. The tumor cells are mitotically active and are the precursor cells that develop into sustentacular and neuronal cells. They usually present as a soft tissue mass in the superior olfactory recess involving the anterior and middle ethmoid air-cells on one side and extending through the cribriform plate into the anterior cranial fossa. Based on the duration of symptoms,<unk>  may be classified into two subtypes neuroblastoma proper and neuroendocrine carcinomas. Genes involved in the pathogenesis of<unk>  include chromosomal gains in 7q11 and 20q and deletions in 2q, 5q, 6p, 6q, and 18q. On gross pathology, soft and hemorrhagic, polypoid appearance, and rich and fragile vascular supply of the tumor are characteristic findings of<unk> . On microscopic histopathological analysis, arrangements of cells into rosettes or pseudorosettes are characteristic findings of<unk> . The incidence of<unk>  is approximately 0.4 per 100,000 individuals worldwide.<unk>  can present in a wide range of age groups; however, it is mostly noted in a bimodal distribution, occurring most frequently in the second and sixth decades of life. There is no racial predilection to the<unk> . There are no established risk factors for<unk> .
If left untreated, 10%-62% of patients with<unk>  may progress to develop metastasis. Common complications of<unk>  include tumor recurrence and metastasis. These tumors often display varying biologic activity ranging from indolent growth, with patient survival exceeding 20 years, to a highly aggressive neoplasm capable of rapid widespread metastasis, with survival limited to a few months. The five-year mortality rate of patients with<unk>  is approximately 56% and 20% for grade I and II and grade III and IV tumors, respectively. The ten-year mortality rate of patients with<unk>  is approximately 67% and 34% for grade I and II and grade III and IV tumors, respectively. Symptoms of<unk>  include nasal obstruction, epistaxis, ear pain, otitis media, hyposmia, nasal discharge, facial pain, changes in vision, lacrimation, facial numbness, and anosmia. Common physical examination findings of<unk>  include reddish-gray, polypoid mass located in the upper nasal fossa, epistaxis, nasal discharge, nasal pain, facial swelling, trismus, proptosis, diplopia, anosmia, serous otitis media, cervical lymphadenopathy, retropharyngeal lymphadenopathy, decreased visual acuity, extraocular movement paralysis, altered mental status, and frontal headaches. Biopsy may be helpful in the diagnosis of<unk> . Findings on biopsy diagnostic of<unk>  include small, round-to-oval cells with coarsely granular chromatin, prominent nuclear membranes, multiple small nucleoli, and scant cytoplasm with pseudorosette or occasional Homer-Wright rosettes separated by fibrous septa. Calcification and necrosis are sometimes seen, and mitotic figures are rare. On head and neck CT,<unk>  is characterized by soft tissue attenuation, with relatively homogenous enhancement. Head and neck MRI scan is diagnostic of<unk> . On head and neck MRI,<unk>  is characterized by heterogenous intermediate signal on T1 and T2weighted MRI and  variable enhancement on T1 contrast with gadolinium. The predominant therapy for<unk>  is surgical resection followed by postoperative irradiation. Adjunctive radiation/chemotherapy may be required. The optimal therapy for<unk>  depends on the stage at diagnosis and regional or distant metastasis.
Esthesioneuroblastoma
Neuroma
Mycetoma
PEComa
Hamartoma
Neurofibroma
Ganglioneuroma
Glomus tumor