Ancient Schwannoma of the hard palate. An uncommon case report and review.

Schwannoma or neurilemmoma is an infrequent benign tumor in the oral cavity that originates from the Schwann cells on the neural sheath of the peripheral nerves. Schwannomas are frequently located in the soft tissues of head and neck region, but only a 1 to 12% of them are located in the oral cavity. Some histological variants of schwannoma have been described including the cellular, plexiform, epithelioid, ancient, and melanocytic types. The "ancient schwannoma" is an uncommon variant of this tumor that shows specific histological characteristics, and is rare in the oral cavity with less than 15 cases described on the literature. Most of them were located in the tongue or in the floor of the mouth, being the hard palate an extremely rare localization. We present a new clinical case of an ancient schwannoma with a long time of evolution, arising from the nasopalatine nerve, and located in the hard palate of a 35 year old female. We also review the main clinical and histological characteristics of this pathology. Key words:Ancient schwannoma, neurilemmoma, palate, schwannoma.

Overexpression of cyclooxygenase-2 as a biomarker in different subtypes of the oral lichenoid disease.

OBJECTIVE: Oral lichenoid disease (OLD) includes a number of chronic inflammatory processes including oral lichen planus (OLP) and oral lichenoid lesions (OLL) with controversial diagnosis and prognosis. Cyclooxygenase-2 (COX-2) is a key enzyme for inflammatory processes and cellular proliferation. Its overexpression in some premalignant chronic inflammatory diseases and malignant neoplasias could point to its potential as a prognostic factor. The aim of this study was to analyze the COX-2 expression in different subtypes of OLD because of its potential to be a marker of altered behavior. STUDY DESIGN: Forty-four samples from OLD patients were studied (30 females and 14 males) and classified according to their clinical (C1: only papular lesions/C2: papular and other lesions) and histological features (HT: OLP typical/HC: OLP compatible) according to published criteria. Standard immunohistochemical procedure was performed for COX-2 expression and a comparative and descriptive statistical analyses were performed. RESULTS: Epithelial COX-2 overexpression was observed in 24 (54.5%) cases (C1: 13 [54.2%]/C2: 11 [45.8%], HT: 9 [37.5%]/HC: 15 [62.5%], P = .032). Inflammatory COX-2 overexpression was observed in 14 (31.8%) cases (C1: 6 [42.9%]/C2: 8 [57.1%], HT: 4 [28.6%]/HC: 10 [71.4%], P = .032). CONCLUSION: Differences in COX-2 expression in subtypes of OLD may distinguish cases with a higher premalignant potential.