Intraneural Perineurioma in the Tongue: A Case Report

We report a case of an intraneural perineurioma that developed in an unusual location, the tongue. A 16-year-old male presented with a 1 cm sized protruding submucosal mass in his tongue without any sensory or motor signs or symptoms. The mass was excised. The mucosa was intact, with an ill-defined firm mass measuring 1.0 x 0.8 x 0.6 cm in the submucosa and muscle. The cut surface of the mass was pinkish gray and fibrotic. Microscopically, the mass contained tortuous and thickened peripheral nerve bundles in the submucosa, showing onion bulb like structures. The onion bulb like structures consisted of centrally located S-100 protein positive Schwann cells surrounded by Glut-1 positive perineurial cells. The FISH study did not reveal any genetic aberrations in chromosome 22.

Multiple schwannomas / 中华骨科杂志

Objective To study the clinical features and treatment of multiple schwannomas (neurilemmomas). Methods 9 patients with multiple schwannomas treated with surgery from 1975 to 1999 were reviewed retrospectively. Results In 7 of the 9 cases of schwannomas, the number of tumor lesions was seen more than that diagnosed preoperatively. All the patients had surgical resection; 5 had enucleation and 4 had tumors excised with the invovled nerve. Recurrence occured in 4 patients. Conclusion Because of the difficulty in predetermination of the exact lesional number, thoroughly preoperative examination including MRI is nessesary. Enucleation is recommended to those tumors involving important nerves. There is a high rate of recurrence.

Loss of NF2 Gene in Neurofibromatosis Type 2－ Associated Cutaneous Schwannomas / 中华皮肤科杂志

Objective The loss of NF2 gene in cutaneous schwannomas of neurofibromatosis type 2 patients was investigated in order to explore the tumorigenesis and characteristics of NF2 tumor suppressor gene, and to provide evidence for presymptomatic gene diagnosis for NF2 patients. Methods DNA was extracted from whole blood and frozen tumor tissue, respectively. Genotyping was performed using 6 microsatellite markers flanking or within the NF2 gene: CRYB2－ D22S193－ NF2CA1－ NF2CA3－ D22S268－ D22S430, which is tightly linked to the NF2 gene and analyzed on an ABI Genetic Analyzer 310 after PCR amplification. Results A total of 18,14,0,13,16,12 samples showed loss of heterozygosity at microsatellite markers CRYB2， D22S193， NF2CA1， NF2CA3， D22S268， D22S430 in 43 samples of cutaneous schwannomas, respectively. Conclusions The method for detection of NF2 allelic loss was established. Frequent allelic loss reconfirms that NF2 gene is a tumor suppressor gene. The observation that tumors with or without allelic loss of the NF2 gene exist in the same patient indicates that these tumors are originated from different clones in which genetic alterations occurred independently.