Solitary fibrous tumor of the oral cavity: clinicopathologic and immunohistochemical study of 21 cases.

We describe clinical, morphologic, and immunohistochemical features of 21 cases of solitary fibrous tumor presenting in the oral cavity. There were 9 male and 12 female patients with a median age of 51 years (range 37-83). The most common locations included the buccal mucosa (the most common site), lip, maxillary or mandibular vestibule and tongue. Histopathologic examination showed well-circumscribed tumors with two well-defined patterns: the classic pattern with densely cellular areas alternating with hypocellular areas in a variably collagenous, vascular stroma and a more uniformly sclerotic pattern with only subtle classic areas. The spindle-shaped neoplastic cells consistently showed immunoreactivity for antibodies directed against CD34. Five of nineteen cases (26%) were reactive for CD99 and 19 of 19 for Bcl-2. Follow-up information was available in 17 cases and averaged 54 months, with no evidence of recurrence or metastasis in any of these patients. Awareness that solitary fibrous tumor may present in the oral cavity is important so that confusion with other spindle cell neoplasms can be avoided. We also briefly describe the differential diagnosis and compare this series, the largest single series of intraoral SFT, to cases previously reported in the literature.

Dysplasia of the upper aerodigestive tract squamous epithelium.

Dysplasia of the oral, laryngeal and oropharyngeal stratified squamous epithelia is a microscopically defined change that may occur in clinically identifiable lesions including erythroplakia, leukoplakia and erythroleukoplakia, lesions that convey a heightened risk for carcinomatous progression. Dysplastic lesions have been classified microscopically according to degree of cytologic atypia and changes in architectural patterns, usually on a three part or four part gradation scale. Vocal cord epithelial lesions are graded according to either the Ljubljana or the World Health Organization (WHO) system whereas oral dysplasias are generally classified according to WHO criteria. Cytologically atypical cells are considered to represent precancerous changes predicting an increase risk for carcinomatous transformation. Inter- and intra-rater reliability studies among pathologists have disclosed low correlation coefficients for four part grading systems, whereas improved agreement is achieved (kappa correlation values) using the Ljubljana systems. Evidence forwarded by some studies supports the prognostic value of progressively severe dysplastic changes for carcinomatous transformation; however, some studies indicate that the presence of a clinically defined lesion without microscopic evidence of dysplasia also connotes increased risk for carcinomatous transformation. Loss of heterozygosity (LOH) at 3p and 9p microsatellite domains, DNA ploidy analysis and nuclear image analyses may have predictive value as molecular and histomorphological biomarkers.

Evidence-based practice of oral pathology and oral medicine.

Oral pathology is the specialty area of dentistry that deals with the diagnosis and management of oral diseases and more specifically, diseases other than dental caries, periodontal disease, restorative dentistry, and orthodontic therapy. Oral medicine represents the clinical arm of oral pathology and deals with diagnosis and treatment of soft-tissue lesions, whereas oral histopathology is the specialty area that focuses on the microscopic diagnosis of soft- and hard-tissue lesions of the head and neck area. The diagnosis and treatment of oral pathologic conditions is often based on empirical decision-making and many approaches to treatment have not been well-supported by clinicopathologic studies. The need for evidence-based, scientifically documented approaches to both diagnosis and treatment is eminent. Specific diagnostic criteria are lacking for many oral diseases, and therapeutic strategies have not been assessed by the gold standard of placebo-controlled, double-blind trials. Additionally, there are scientific data in the published literature that continue to be ignored by dental practitioners who manage patients with oral pathologic conditions. In this article, specific disease entities that are commonly managed by oral pathologists and oral medicine practitioners will be discussed with recommendations for future scientific studies that can serve as a framework for evidence-based diagnostic and therapeutic approaches.