Classic neurothekeoma (nerve sheath myxoma) and cellular neurothekeoma of the oral mucosa: immunohistochemical profiles.

BACKGROUND: Classic neurothekeoma (nerve sheath myxoma) is regarded as being a true benign cutaneous tumor of nerve sheath origin. Cellular neurothekeoma was separated from the classic type by histogenesis, morphology and immunophenotype. Whether cellular neurothekeoma represents a continuum within the spectrum of classic neurothekeoma or is an independent entity is controversial. Only a small number of classic neurothekeomas of the oral mucosa have been reported and there are even fewer publications on cellular neurothekeoma. We analyzed a series of oral neurothekeomas (classic and cellular) with a panel of neural and other mesenchymal markers to enhance their diagnosis and classification. METHODS: One cellular and three classic neurothekeomas were submitted to a panel of immunohistochemical stains with antibodies against S100, S100A6, NSE, NKI/C3, PGP9.5, α-SMA, HHF-35, CD68 and vimentin. Two cases of neurofibroma (plexiform type), representing a true lesion of neural origin, served as control. RESULTS: The cellular neurothekeoma yielded a positive immunoreaction for S100A6 and NKI/C3 and a negative immunoreaction for S-100. The classic neurothekeomas demonstrated a positive reaction for S-100 and S100A6, but a negative one for NKI/C3. Other markers were non-contributory to distinguishing between these types of lesions. CONCLUSIONS: The small number of reported oral neurothekeomas (classic and cellular) could be due, in part, to the lack of recognition of their particular morphologic and immunohistochemical features. Our results indicate that testing for NKI/C3 immunoreactivity may be of value in distinguishing between cellular and classic neurothekeoma.

Retrospective review of pediatric oral lesions from a dental school biopsy service.

UNLABELLED: This report presents a review of the results from 5457 biopsies of patients, 0-16 years of age, received over 15 years at the University of the Pacific School of Dentistry (Pacific Oral and Maxillofacial Pathology Laboratory). PURPOSE: To carry out the largest and most up to date U.S. survey of oral specimens from children. METHOD: The computerized data was retrieved and compiled for age and diagnoses. The lesions were divided by the MIND classification system into 1) Metabolic 2) Inflammatory 3) Neoplastic and 4) Developmental. RESULTS: Inflammatory lesions formed the largest group of biopsies (2758, 51%) followed by Developmental conditions (1928, 35%) and Neoplasms (734, 13%). Dentigerous cysts were the most common lesions, followed by the mucous retention phenomenon (mucocele). The 15 most frequently occurring lesions accounted for 80% of all biopsies. Eight malignancies and 22 benign aggressive tumors were also included. CONCLUSIONS: 1. Pathoses increase with age. 2. Results from our study are similar to most of the other studies. 3. More serious pathoses occur in some countries where there is limited access to care, resulting in patients seeking care only when symptomatic. 4. Oral malignancies are rare, but as with any malignancy, early diagnosis renders a more favorable prognosis.

Granular cell tumor of the oral cavity: updated immunohistochemical profile.

BACKGROUND: Granular cell tumor (GCT) is a benign lesion that occurs at different body sites with preponderance to the oral cavity. It is generally believed to be of schwann cell/neural cell origin. We used a large panel of both traditional and recently developed antibodies in an attempt to trace the origin of GCTs on the basis of their immunoprofile. METHODS: The patients' demographic data and the cytological and architectural features of the lesions were analyzed in a large series of oral GCTs (n = 68). Forty-two lesions were also submitted to a panel of immunohistochemical stains with antibodies against S-100, CD-68 (KP-1 and PG-M1), vimentin, calretinin, NKI/C3, PGP9.5, p75/NGFR and inhibin-alpha. RESULTS: The tongue was the most common location of oral GCTs (81%). The granular cells demonstrated a wide array of cytological features in terms of cell shape and position of the nucleus. In addition, the lesions showed different architectural patterns, including 'infiltration' with satellite nodules. Interestingly, no recurrences were reported, even in lesions that were not completely excised. Granular cells were usually found to be strongly and diffusely positive for p75, vimentin, calretinin and NKI/C3, inhibin-alpha, PGP9.5, and S-100. CONCLUSIONS: Immunoreactivity of the granular cells to a broad panel of antibodies that characterize different tissues does not confirm any particular cell type for the histogenetic origin of GCTs. Furthermore, GCTs could be regarded as lesions that reflect a local metabolic or reactive change rather than a true neoplasm.

Relative frequency of intra-oral minor salivary gland tumors: a study of 380 cases from northern California and comparison to reports from other parts of the world.

BACKGROUND: The relative frequency of individual intra-oral minor salivary gland tumors (IMSGT) is not well documented in the literature. The aim of this study was to determine the relative frequency and distribution of IMSGT in an oral pathology biopsy service and to compare the data with similar studies from different parts of the world. METHODS: Files from the Pacific Oral and Maxillofacial Pathology Laboratory of the University of the Pacific, San Francisco, California served as a source of material for this study. Files were systematically searched for all cases of IMSGT during a 20-year period. Tumors were classified according to the 2005 WHO classification of salivary gland tumors. RESULTS: IMSGT were identified in 380 (0.4%) cases of 92 860 accessed. This is the largest series of IMSGT from one source reported in recent years. Of the 380 tumors, 224 (59%) were benign and 156 (41%) were malignant. Of the benign tumors, pleomorphic adenoma (PA) was the most common (39.2%), followed by cystadenoma (6.3%), canalicular adenoma (6.1%), ductal papillomas (4.4%), basal cell adenoma (1.6%), and myoepithelioma (1.3%). Of the malignant tumors, mucoepidermoid carcinoma was the most common (21.8%), followed by polymorphous low-grade adenocarcinoma (7.1%), adenoid cystic carcinoma (6.3%), adenocarcinoma, not otherwise specified (NOS; 2.1%), acinic cell carcinoma (1.6%), clear cell carcinoma, NOS (1.0%), and carcinoma ex PA (0.5%). CONCLUSIONS: Studies related to the relative frequency of individual IMSGTs from different parts of the world are difficult to compare because many studies are outdated, the number of cases is small, the list of tumors is limited, and new entities are not included. To determine the true relative frequency, more studies should be conducted, on a large number of cases from one source, by experienced pathologists in the field of salivary gland tumors.

Relative frequency of central odontogenic tumors: a study of 1,088 cases from Northern California and comparison to studies from other parts of the world.

PURPOSE: To determine the relative frequency of central odontogenic tumors in relation to all biopsy specimens and to one another in an oral pathology biopsy service and to compare the data with previous studies from different parts of the world. METHODS: Files from the Pacific Oral Pathology Laboratory of the University of the Pacific, San Francisco, CA served as a source of material for this study. Files were systematically searched for all cases of central (intraosseous) odontogenic tumors during a 20-year period. RESULTS: Central odontogenic tumors were identified in 1,088 (1.2%) cases out of the 91,178 accessed. Individually, of all odontogenic tumors, 75.9% were odontomas. The prevalence of the remaining tumors appears to be a rare occurrence. The second most common was ameloblastoma (11.7%), followed by odontogenic myxoma (2.2%). Odontomas are considered hamartomas or developmental anomalies. When excluded from the list of individual odontogenic tumors, ameloblastoma is the most common (48.5%), followed by odontogenic myxoma (9.2%), adenomatoid odontogenic tumor (7.3%), ameloblastic fibro-odontoma (7.3%), ameloblastic fibroma (6.5%), calcifying odontogenic cyst (6.5%), and odontogenic fibroma (6.1%). Each remaining tumor comprises less than 4%. CONCLUSIONS: Studies related to the relative frequency of individual odontogenic tumors from different parts of the world are difficult to compare because most studies are outdated, the list of tumors is limited, and new entities are not included. To determine the real relative frequency, further studies should be conducted, especially in Western societies, by experienced pathologists in the field of odontogenic tumors.

Relative frequency of peripheral odontogenic tumors: a study of 45 new cases and comparison with studies from the literature.

BACKGROUND: Peripheral (extraosseous) odontogenic tumors are rare, and reports in the literature have mainly been single case reports or a small series of cases. The aim of this study was to determine the relative frequency of peripheral (extraosseous) odontogenic tumors relative to one another and relative to their central (intraosseous) counterparts in an oral pathology biopsy service and to compare these data with information available in the literature. METHODS: The files of the Pacific Oral and Maxillofacial Pathology Laboratory of the University of the Pacific, San Francisco, CA, USA, served as the source of material for this study. Files were systematically searched for all cases of peripheral odontogenic tumors (POTs) during a 20-year-period. RESULTS: There were 91,178 cases accessed in which central and POTs were identified in 1,133 (1.24%), central tumors in 1,088 (1.2%), and peripheral tumors in 45 (0.05%). Peripheral tumors accounted for 4% of all 1133 central and POTs. Peripheral odontogenic fibroma (PODF) was the most common of the 45 POTs accounting for 51.1% (23 cases) followed by peripheral ameloblastoma (PA) 28.9% (13 cases) and peripheral calcifying cystic odontogenic tumor (PCCOT) 13.3% (six cases). Peripheral calcifying epithelial odontogenic tumor, peripheral ameloblastic fibroma, and peripheral ameloblastic carcinoma were also identified--each comprised 2.2% (one case each). PODF was more common than its central counterpart by a 1.4:1 ratio. This was the only peripheral tumor that was more common than its central counterpart. PA accounted for 9.3% of all ameloblastomas and PCCOT for 26% of all calcifying cystic odontogenic tumors. CONCLUSION: There is only scarce information in the literature on the relative frequency of POTs. Additional studies should be conducted to determine the true relative frequency. To ensure accuracy, pathologists with experience in the field of odontogenic tumors should conduct these studies. Intraosseous tumors that perforate through the bone to the gingival tissue, clinically presenting as 'peripheral tumors' should be excluded.

Selective ablation of surface enamel caries with a pulsed Nd:YAG dental laser.

BACKGROUND AND OBJECTIVE: High intensity infrared light from the pulsed Nd:YAG dental laser is absorbed by carious enamel and not absorbed by healthy enamel. Consequently, this system has potential for selective removal of surface enamel caries. Safety and efficacy of the clinical procedure was evaluated in two sets of clinical trials at three dental schools. Selective ablation was evaluated with FTIR spectroscopy. STUDY DESIGN/MATERIALS AND METHODS: Carious lesions were randomized to drill or laser treatment. Pulp diagnosis, enamel surface condition, preparations, and restorations were evaluated by blinded evaluators. In Study I, surface caries were removed from 104 third molars scheduled for extraction. One-week post-treatment teeth were evaluated clinically, extracted, and the pulp was examined histologically. In Study II, 90 patients with 462 lesions on 374 teeth were randomized to laser or drill and followed for 6 months. RESULTS: Pulsed Nd:YAG laser removal of surface enamel caries was demonstrated to be both safe and effective. Caries were removed in all conditions. There were no adverse events and both clinical and histological evaluations of pulp vitality showed no abnormalities. A significantly greater number of preparations in the drill groups vs. laser groups entered dentin (drill = 11, laser = 1, P = 0.007). CONCLUSION: The more conservative laser treatment removed the caries but not the sound enamel below the lesion. The pulsed Nd:YAG dental laser was found to be both safe and effective for surface caries removal.

Cementoblastoma: an innocuous neoplasm? A clinicopathologic study of 44 cases and review of the literature with special emphasis on recurrence.

The clinicopathologic features of 44 cases of cementoblastoma were analyzed and compared with those of 74 cases from the literature with special emphasis on the clinical behavior, treatment, and recurrence rate of these relatively rare benign odontogenic neoplasms. The cases in the current series were accessioned at the Armed Forces Institute of Pathology, Washington, DC. Patient ages at diagnosis ranged from 8 years to 44 years, with a mean age of 20.7 years. The tumors affected 30 males and 14 females. The mandible was the site of occurrence in 31 cases (70.4%), with the mandibular first molar the most common tooth involved. Radiographically, more than 90% of the tumors presented as well-defined radiopaque or mixed-density masses confluent with the tooth root(s) and surrounded by a radiolucent rim. Two lesions were radiolucent. Microscopically, cementoblastomas share similar features with osteoblastomas but are unique because of their physical attachment to the tooth root(s). Follow-up was obtained in 35 of 44 cases, with a mean follow-up interval of 5.5 years. Recurrence was documented in 13 cases (37.1%), in contrast to the literature, where only 2 of 34 cases (5.9%) with adequate follow-up recurred. Jaw expansion and perforation of the cortex were noted in a higher percentage of recurrent than nonrecurrent tumors. Because recurrence and continued growth are possible if lesional tissue remains after initial surgery, appropriate treatment should consist of removal of the lesion along with the affected tooth or teeth, followed by thorough curettage or peripheral ostectomy.

Bloodborne pathogens: current concepts.

In the early 1980s, the AIDS hysteria began to gain momentum. As a direct result of this phenomenon, the delivery of dental care changed dramatically. By 1989, most dentists had begun to accept the concept of universal precautions and compliance with infection control recommendations from the Centers for Disease Control and Prevention and the Organization for Safety & Asepsis Procedures. The emergence of bloodborne pathogens from the 1970s has been a significant milestone in the history of the dental profession. Patients infected with human immunodeficiency virus, hepatitis B virus, and hepatitis C virus are commonly encountered in the modern dental practice, and dental providers need to have a thorough knowledge about bloodborne diseases and the dental management of patients presenting with these diseases.

Comparison of computer-assisted brush biopsy results with follow up scalpel biopsy and histology.

Oral brush biopsy results were compared with scalpel biopsy and histology to determine the positive predictive value of an abnormal brush biopsy finding. Of 243 patients with abnormal brush biopsies, 93 proved positive for dysplasia (79) or carcinoma (14) and 150 were negative for either dysplasia or carcinoma. Therefore, the positive predictive value of an abnormal brush biopsy was 38% (93/243). By using the oral brush biopsy, dentists can inform their patients that abnormal findings have a strong positive predictive value for dysplasia or carcinoma and therefore require follow-up confirmation by scalpel biopsy.