Clinical and histopathological studies of olfactory neuroblastoma

Six patients of olfactory neuroblastoma were treated, and two of them were studied with electron microscopy and immunohistochemical staining. These patients, four male and two female, ranged in age from 37 to 73 years old. Five patients had nasal bleeding, and only one patient had frontal pain and optic disorder without nasal bleeding. None of the patients had metastasis. However, three patients had local recurrence and invasion into the intracranial region. The tumors of three patients were confined to the nasal cavity and one or more paranasal sinuses. The tumors of the other three patients extended beyond the nasal cavity and paranasal sinuses. Two patients, treated with radiotherapy and cryosurgery, died of the disease 7 and 21 years after treatment, respectively. Two patients, treated with radiotherapy alone or a combination of radiotherapy and chemotherapy, died of other causes without recurrence 2 and 3 years later, respectively. A patient treated with craniofacial resection alone is still alive after 4 years. However, he has local recurrence and has been treated with radiotherapy and adjuvant chemotherapy. The last patient, treated with craniofacial resection following radiotherapy, is still alive after 3 years without any symptoms of recurrence. The two most recent cases were studied with electron microscopy, stains for PAS, Grimelius and Bodian, and immunohistochemical staining for S-100 protein, neuron-specific enolase, and glial fibrillary acidic protein. The tumor cells of one case were well differentiated because they contained neurosecretory granules and neurites, and the tumor cells of the other case were poorly differentiated because they contained only neurites-like structures.