Peripheral ameloblastic fibroma of the maxilla: report of a case and review of the literature.

Peripheral odontogenic lesions are considered to be rare within the classification of odontogenic tumors. Also referred to as extraosseous or soft tissue odontogenic tumors, peripheral odontogenic tumors share the same histopathologic characteristics of their central or intraosseous counterparts. Ameloblastic fibroma is a rare odontogenic tumor that arises from both odontogenic epithelium and connective tissue. Only 2 cases of peripheral ameloblastic fibroma have been reported in the English-language literature, one of which did not show the classic features of an ameloblastic fibroma. In this report, we describe a rare case of a peripheral ameloblastic fibroma in the maxilla of a 3-year-old girl.

Balloon cell nevus of the oral mucosa.

The balloon cell nevus is an uncommon variant of melanocytic nevi in which the majority of the proliferation consists of cells demonstrating peculiarly large clear, foamy, or finely vacuolated cytoplasm. The vacuolated cells represent altered nevus cells and upon immunoperoxidase evaluation react positively with several melanocytic markers. Complete excision results in cure. This report describes the second balloon cell nevus of the oral mucosa documented in the English-language literature.

Resolution of an oral ulcer secondary to acetaminophen/hydrocodone withdrawal.

Acetaminophen/hydrocodone is a common non-opioid/opioid analgesic indicated for the treatment of moderate to severe pain. The following report depicts a unique case involving a 57-year-old woman with a persistent, painful oral ulcer that was unresponsive to standard treatments. The ulcer was resolved when the patient discontinued acetaminophen/hydrocodone use. The cause of the ulcer is unclear but it was speculated to result from a systemic hypersensitivity reaction to acetaminophen/hydrocodone.

Overexpression of p16INK4 is a reliable marker of human papillomavirus-induced oral high-grade squamous dysplasia.

OBJECTIVE: Human papillomavirus (HPV) infection has been implicated in the development of high-grade squamous dysplasia and carcinoma of the oral cavity in the absence of other known risk factors such as smoking. HPV-induced oral dysplasia or carcinoma may be a unique tumor entity in terms of biologic behavior and treatment decisions. In detecting such cases, most reported studies have used techniques that are less sensitive than DNA amplification. Recent reports have suggested that overexpression of the p16INK4 protein is a surrogate marker of HPV-induced high-grade dysplasia or carcinoma. However, the correlation between expression of p16INK4 and the presence of HPV DNA as determined by polymerase chain reaction (PCR) amplification has not been previously reported. The purpose of this research was to determine if immunohistochemistry for p16 would serve as a marker of HPV-associated high-grade oral squamous dysplasia. STUDY DESIGN: Archival formalin-fixed, paraffin-embedded tissue sections from 41 cases of high-grade oral squamous dysplasia were randomly selected. Expression of p16INK4 protein was assessed by immunohistochemical analysis (16P04 Neomarkers, Fremont, CA). Strong and diffuse nuclear staining restricted to the dysplastic region in the epithelium was scored as positive for protein expression, whereas focal or weak nuclear or cytoplasmic staining was scored as negative. The presence of HPV was determined by microdissection, DNA extraction, and PCR DNA amplification using elongated primers that align with corresponding sequences of the L1 region of 23 mucosotropic HPV genotypes. The HPV type was determined by direct sequencing of the PCR product. Normal squamous epithelium was used as an internal negative control, and cases of severe cervical high-grade squamous dysplasia were used as a positive control for immunohistochemical staining and PCR. RESULTS: The results of immunohistochemical analysis for overexpression of p16INK4 were positive in 6 of the 41 tissue sections. The results of PCR DNA amplification were also positive for these 6 sections. HPV-16 was identified in 5 of the positive cases; in the other case, the viral strain could not be determined. CONCLUSIONS: Immunohistochemical detection of p16INK4 is a technically simple and potentially reliable assay for diagnosing cases of HPV-induced oral high-grade squamous dysplasia. Detecting such lesions may influence future therapeutic decisions.

Diagnosis and management of Wegener's granulomatosis in a dog.

A four-year-old maele/neutered mixed-breed dog was prsented for severe, multifocal, proliferative gingivitis. Histopathologic examination of incisional biopsies supported a diagnosis of Wegener's granulomatosis, an autoimmune vasculitis previously unreported in the veterinary literature. Diagnostic investigations for infectious, neoplastic, or other inflammatory conditions all provided negative results. Management with a combination of immunosuppressive agents resulted in complete resolution and remission of the presenting lesions and associated clinical signs.

Intraneural perineurioma--not restricted to major nerves.

The intraneural perineurioma is an uncommon proliferation of perineural cells that forms onion bulb-like structures surrounding the nerve axons within a portion of a single affected nerve. The etiology is idiopathic, and it is controversial whether the process is reactive or neoplastic. All previously reported cases have involved major nerves and have been associated with motor deficits and, less frequently, sensory signs or symptoms. The current case represents the first example shown to arise in a small unnamed nerve before the development of clinically detectable nerve dysfunction. The process appears to be progressive; and when detected in a small nerve, excision is recommended to prevent proximal extension and possible development of motor or sensory deficits.