Ultrastructural diagnosis of facial nerve schwannoma using fine needle aspiration.
In a 14-year-old boy presenting with left facial nerve paralysis, physical examination revealed a soft, round mass in the floor of the left external auditory canal. A fine needle aspiration biopsy was performed to obtain material for light and electron microscopy. Several small groups of uniform, spindle-shaped neoplastic cells were present on the slides; a malignant mesenchymal tumor was considered, but a definite diagnosis could not be established under light microscopy. The ultrastructural examination revealed spindle-shaped and stellate cells with multiple parallel cytoplasmic processes lined with a well-developed basal lamina; these features are highly characteristic of a benign schwannoma.
D000293:Adolescent; D001707:Biopsy, Needle; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D005154:Facial Nerve; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009442:Neurilemmoma / Q000175:diagnosis / Q000648:ultrastructure*; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis / Q000648:ultrastructure*