Ameloblastic fibro-odontoma: a clinicopathologic study of 12 cases.

OBJECTIVE: The ameloblastic fibro-odontoma (AFO) is an uncommon odontogenic tumor occurring in childhood with limited reported data on recurrence. The purpose of this AFO study was to review its clinicopathologic features, investigate treatment modalities and establish a recurrence rate. STUDY DESIGN: The clinicopathologic features of 12 new cases of AFO were analyzed and compared with those of 208 cases from the literature, with special emphasis on the clinical behavior, treatment, and recurrence rate. RESULTS: The average age was 9.4 (+/- 6.7) years with a male-to-female ratio of 1.6:1. The mandible was the site of occurrence in 59.5%. The tumor most often presented radiographically as a unilocular mixed density lesion associated with the crown of an impacted tooth. Displacement of teeth, delayed eruption and bony expansion were commonplace. There were 5 recurrences among 68 cases with adequate follow-up for a recurrence rate of 7.4%. All recurrences were attributed to incomplete removal at the time of the initial surgery. CONCLUSIONS: The AFO is a childhood tumor most often affecting the posterior jaws and frequently causing bony expansion with profound affects on the dentition. Conservative surgical removal with extraction of the associated teeth is recommended. The established recurrence rate is less than 10%.

Protein fixation and antigen retrieval: chemical studies.

Abstract Fixation with formaldehyde is the first process to which most biopsy and necropsy specimens are exposed prior to dehydration and embedding in paraffin wax. Tissue specimens that have been fixed in formaldehyde have architectural characteristics that are familiar to virtually every pathologist and these facilitate routine diagnosis. Nevertheless, formaldehyde fixation has some deleterious effects including reduction in immunoreactivity and degradation of nucleic acids. Development of methods to counteract these deleterious effects requires an understanding of the chemical events that occur during tissue fixation and subsequent tissue processing. This short review illustrates some of the chemical consequences of formaldehyde fixation and ethanol dehydration. It also provides some insight into the molecular events accompanying heat-induced antigen retrieval.

Simultaneous magnetically directed drug convection and MR imaging.

Superparamagnetic iron oxide nanoparticles (IO NPs) are of interest for their usefulness in biomedical applications. In this work, we have synthesized iron oxide nanocomposites surface-modified with different biocompatible polymers. Bovine serum albumin (BSA) was physisorbed onto these IO NPs along with an excipient during freeze-drying. The mass transport of the protein attached to the iron oxide core-shell nanoparticles (IO cs-NPs) under a gradient magnetic field of an MRI instrument was observed in vitro and in an egg as a model system for a biological fluid. From the in vitro experiments in agarose gels, it was observed that the protein gets separated from the core during mass transport for some cs-IO, but co-migration was observed for PEG-modified IO cs-NPs. These experiments demonstrated proof-of-concept for the use of IO cs-NPs in magnetically directed drug convection.

Development and validation of opioid ligand-receptor interaction models: the structural basis of mu vs delta selectivity.

Opioid receptor binding conformations for two structurally related, conformationally constrained tetrapeptides, JOM-6 ( micro receptor selective) and JOM-13 (delta receptor selective), were deduced using conformational analysis of these ligands and analogs with additional conformational restrictions. Docking of these ligands in their binding conformations to opioid receptor structural models, based upon the published rhodopsin X-ray structure, implicates specific structural features of the micro and delta receptor ligand binding sites as forming the basis for the micro selectivity of JOM-6 and the delta selectivity of JOM-13. In particular, the presence of E229 in the micro receptor (in place of the corresponding D210 of the delta receptor) causes an adverse electrostatic interaction with C-terminal carboxylate-containing ligands, resulting in the observed preference of ligands with an uncharged C-terminus for the micro receptor. In addition, the requirement that the Phe3 side chain of JOM-13 assume a gauche orientation for optimal delta binding, whereas the Phe3 side chain of JOM-6 must be in a trans orientation for high-affinity micro binding can be largely attributed to the steric effect of replacement of L300 of the delta receptor by W318 of the micro receptor. Testing this hypothesis by examining the binding of JOM-6 and several of its key analogs with specific micro receptor mutants is described. Our initial results are consistent with the proposed ligand-receptor interaction models.

Benign fibro-osseous lesions: a review of current concepts.

The benign fibro-osseous lesions (BFOL) represent a clinically diverse group of disorders of bone that share similar histopathologic features. As a group, they are relatively common in the craniofacial complex, especially the jaws. Although the general concept of BFOL is relatively well known, specific diagnostic interpretation of individual cases is often challenging. New concepts and controversies have arisen over the past 10 to 15 years regarding classification and diagnostic criteria. However, among the new theories and contentions, there is now essential agreement that the osseous dysplasias represent a single disease process, while the so-called "juvenile active ossifying fibroma" and other "aggressive," "active," "psammomatoid" ossifying/cementifying fibromas remain controversial. This review is presented to update the surgical pathologist on the various entities comprising the spectrum of BFOL and to examine the criteria for their diagnosis.

Subacute necrotizing sialadenitis: report of 7 cases and a review of the literature.

Subacute necrotizing sialadenitis (SANS) is a nonspecific inflammatory condition of unknown etiology affecting oral minor salivary glands. The lesion is most often characterized by a localized palatal swelling, accompanied by an abrupt onset of pain. In this report, we describe the clinical, microscopic, and ultrastructural features of 7 new cases of SANS and combine them with those of 15 cases previously published in the English language medical literature. Patient ages ranged from 15 to 45 years, with a mean age of 21.9 years. A male to female ratio of 3.4 to 1 was observed, but probably reflects a male sampling bias because 14 of the 22 cases occurred in a military population. Seventeen cases occurred on the hard palate, 4 on the soft palate, and 1 on the tonsillar pillar. The lesions were nonulcerated swellings ranging in size from 0.3 to 2.5 cm in diameter. All lesions except one were painful, and most had been present for a week or less at the time of diagnosis. Histopathologic features included diffuse involvement of minor salivary glands by lymphocytes, histiocytes, neutrophils, and variably by eosinophils. Loss of acinar cells, early acinar cell necrosis, and atrophy of ductal cells were also observed. Although possible viral particles have been reported ultrastructurally in some cases of SANS, none were observed in our study. SANS appears to be a self-limiting process with most cases resolving 2 to 3 weeks after biopsy. SANS has been questioned as an entity by some investigators who prefer to include it within the spectrum of necrotizing sialometaplasia. However, we believe there is justification for the separation of these 2 entities based on clinical and histopathologic parameters. Although the specific etiology of SANS remains unknown, it most likely represents an infectious process or perhaps an immune response to an unknown allergen.

Extraosseous calcifying epithelial odontogenic tumor: report of two cases and review of the literature.

In this study two additional cases of extraosseous calcifying epithelial odontogenic tumor are reported, both of which exhibited a prominent clear cell component. The clinical and histopathologic findings of these two cases are compared with those of the nine reported cases from the English language literature. The age range for the 11 cases was 12 to 64 years with a mean age of 34.4 years at the time of diagnosis. Six of the tumors involved female patients and five involved male patients. Seven cases were located on the mandibular gingiva with the remaining four cases involving the maxillary gingiva. On microscopic evaluation, six of the lesions exhibited a predominant clear cell component. Appropriate management of the extraosseous calcifying epithelial odontogenic tumor consists of simple excision. No recurrences have been recorded.

Identification and antibiotic sensitivity of bacteria isolated from periapical lesions.

Periradicular tissues from 28 refractory endodontic cases requiring surgical intervention were submitted for histological diagnosis and microbiological culture. Bacteria isolated from these lesions were identified and then tested for their antibiotic sensitivity to a panel of common antibiotics. The periapical tissue specimens of 22 out of 28 lesions (79%) contained microorganisms. Of the 22 cases showing positive growth cultures, 15 were polymicrobial and 7 were single species isolates. Fifty-three different species were recovered: 29 anaerobes, 19 facultative anaerobes, and 5 aerobes. Microbes were observed under light microscopy in only one case. The most common organisms isolated were Propionibacterium acnes, Staphylococcus epidermidis, Streptococcus intermedius, Wolinella recta, Fusobacterium species, and Clostridium species. Antibiotic susceptibility results showed no clear cut evidence of significant antibiotic resistance among the species tested. The results of this study seem to corroborate earlier studies regarding the microbial population of periapical lesions refractory to nonsurgical endodontics.

Aggressive psammomatoid ossifying fibromas of the sinonasal region: a clinicopathologic study of a distinct group of fibro-osseous lesions.

BACKGROUND: Psammomatoid ossifying fibromas represent a unique subset of fibro-osseous lesions of the sinonasal tract. They have distinctive histomorphologic features and a tendency toward locally aggressive behavior, including invasion and destruction of adjacent anatomic structures. METHODS: Seven cases of psammomatoid ossifying fibromas of the sinonasal tract were identified in the files of the Otolaryngic Tumor Registry at the Armed Forces Institute of Pathology. Medical records, including the clinical history, location of the lesions, radiographs, treatment, and follow-up were reviewed in each case. Follow-up information was available in all of the cases. RESULTS: Four of the patients were male and three were female. The patient's ages ranged from 5 to 54 years (median age, 33 years). Symptoms included facial swelling, nasal obstruction, pain, sinusitis, headache, and proptosis. Radiographic studies confirmed the presence of an osseous and/or soft tissue mass varying in appearance from well demarcated without invasion or erosion to invasive with bone erosion and intracranial extension. Sites of involvement included the nasal cavity and all paranasal sinuses, particularly the ethmoid and maxillary sinuses. Often, more than one sinus was involved and extension of disease included involvement of the orbit, nasopharynx, palate, and anterior cranial fossa. The histologic appearance was characterized by the presence of small mineralized (psammomatoid) bodies admixed with a cellular stroma with a variable amount of myxomatous material and scattered giant cells. Confusion with other osseous and soft tissue tumors may occur resulting in too limited or too aggressive management. En bloc surgical excision is the treatment of choice and may prove curative. Aggressive behavior with recurrence(s) or invasion into adjacent structures occurred. At the time of this writing, the patients are alive over follow-up periods ranging from 6 months to 7 years. CONCLUSIONS: Gnathic and midfacial fibro-osseous proliferations are a diverse group of lesions. A subset of these fibro-osseous lesions with predilection for the sinonasal tract were identified. These lesions are characterized by their distinctive histology, including psammomatoid ossicles and their locally aggressive growth. Complete surgical removal is the treatment of choice.

Diagnosis of ameloblastoma of the maxilla by fine needle aspiration. A case report.

Ameloblastoma is a tumor of odontogenic epithelium that occurs in the jaws. We describe a case of an ameloblastoma of the maxilla that was diagnosed by fine needle aspiration cytology. The patient presented with a mass in the left maxillary sinus. Cytologic examination of the aspirate material showed numerous sheets of tightly packed basaloid cells. Several sheets of cells were surrounded by a row of columnar cells, with the nuclei oriented away from the basement membrane (peripheral palisading). Histologic examination of the resection specimen confirmed the presence of an ameloblastoma of the maxilla.

Fibromatosis of the oral and paraoral region.

The fibromatoses represent a group of infiltrating fibrous proliferations that exhibit a clinical behavior and biologic potential intermediate between benign fibrous lesions and fibrosarcoma. The head and neck region is a common site of involvement for these lesions especially in children and young adults. However, the oral structures per se are not often the site of origin. In this study of 31 cases of fibromatosis that involved the oral and paraoral region, patient ages ranged from birth to 51 years with 74% appearing in the first decade. The most common clinical presentation was a painless mass that involved the cheek, tongue, or submandibular region. Erosion of bone was a frequent finding in lesions arising in soft tissue contiguous with the jaws. After surgical excision, lesions recurred in five patients for a recurrence rate of 23.8%. One lesion recurred twice. The average interval from initial treatment to recurrence was 7.6 months. The recurrence rate observed in this series is significantly lower than that generally reported for fibromatosis of the head and neck (50% to 70%). This is most likely due to the exclusion in this investigation of lesions in the supraclavicular region.

Incisive canal cysts related to periodontal osseous defects: case reports.

The incisive canal cyst is the most common non-odontogenic cyst of the oral cavity. While the cyst has frequently been described, the relationship between the lesion and adjacent periodontal osseous defects has rarely been reported. This paper describes the occurrence and treatment of incisive canal cysts in two patients with severe adult periodontitis on maxillary incisor teeth.

A bacteriological and histological evaluation of 58 periapical lesions.

Periapical tissue from 58 cases requiring periapical surgery was examined histologically and cultured for the presence of microbes. Twenty-nine had a possible oral cavity communication and 29 did not. Approximately one-half of each biopsy was submitted for culture while the other portion was examined histologically. Cultures were positive for the presence of bacteria in 51 of 58 cases while bacteria were seen histologically in only 8 of 58 cases. A total of 50 different species of bacteria were isolated from the 58 cultures of periapical tissue. Of 133 isolates, 87 were strict anaerobes, 37 were facultative anaerobes, and 9 were aerobes. Bacteroides species were found in 17 cultures, always with additional bacteria. Seventeen of 58 biopsies contained foreign particulate matter thought to be root canal sealer. Bacteria were found in periapical granulomas, radicular cysts, and a periapical abscess. According to our data, bacteria, foreign material, missed canals, vertical root fractures, and periodontal disease may all contribute to the chronic, non-healing periradicular lesion.

Necrotizing sialometaplasia. A clinicopathologic study of sixty-nine cases and review of the literature.

The clinicopathologic findings in 69 cases of necrotizing sialometaplasia (NS) were analyzed and compared with 115 reported cases of NS in the English-language literature. Data comparing age, sex, race, location, clinical presentation, and possible predisposing factors are summarized. Analysis of the data indicates that NS can occur in a variety of clinical settings and may exhibit a spectrum of histologic features. Recognition of NS, regardless of its clinical or microscopic presentation, is essential to avoid inappropriate or unnecessary treatment for this benign reactive process.

The paradental cyst: a clinicopathologic study of six new cases and review of the literature.

The paradental cyst is an inflammatory odontogenic cyst arising in conjunction with partially erupted vital teeth associated with pericoronitis. In this study of six cases, these cysts were found primarily adjacent to the buccal root surface of mandibular third molars. Radiographically, they presented as well-defined radiolucencies superimposed over the roots of the affected teeth. Where extracted teeth were available for examination, these cysts were usually associated with a developmental enamel projection or ridge extending into the buccal bifurcation. These developmental anomalies may be instrumental in the pathogenesis of paradental cysts. Although the paradental cyst may represent a distinct entity, a variant of the dentigerous cyst, or an occluded periodontal pocket, it is a useful descriptive term to explain the unique clinical, radiographic, and gross characteristics of this lesion.

Acquired immune deficiency syndrome presenting as a palatal perforation.

Head and neck manifestations are particularly frequent in the acquired immune deficiency syndrome. An unusual case of acquired immune deficiency syndrome in a female prostitute whose initial presentation included a palatal perforation is reported. This case is also noteworthy because the patient died of disseminated miliary tuberculosis, a disease only recently included in the Centers for Disease Control case definition of AIDS.

Intranuclear inclusions correlate with the ultrastructural detection of herpes-type virions in oral hairy leukoplakia.

Hairy leukoplakia (HL) is an Epstein-Barr virus-associated lesion of the oral mucosa that occurs in persons infected with human immunodeficiency virus. Ultrastructural studies have demonstrated herpes-type virions in 63-100% of cases of HL. In this investigation, incisional biopsy specimens from 52 consecutive patients with oral lesions clinically suspicious for HL were analyzed by light and electron microscopy to determine which light microscopic features correlated best with the presence of herpes-type virions ultrastructurally. The predominant histopathologic features consisted of irregular hyperparakeratosis, acanthosis, koilocytoid cells, and an absence of significant inflammation. Candidal organisms and bacterial colonies were variable findings. Intranuclear inclusions, identical to Cowdry type A inclusions seen in other herpesvirus infections, were observed in 46 cases and demonstrated the best correlation with the presence of virions ultrastructurally (p less than 0.0001). Koilocytoid cells also had a statistically significant correlation with the presence of virions (p less than 0.001). We conclude that Cowdry type A inclusions are present in many cases of HL and that their presence, when combined with the other clinical and histologic findings in these lesions, is the most specific light microscopic feature of HL.

Ultrastructural detection of herpes-type virions by negative staining in oral hairy leukoplakia.

Hairy leukoplakia (HL) is a newly recognized virus-associated lesion of oral mucosa that occurs in persons infected with human immunodeficiency virus. Studies have demonstrated Epstein-Barr virus within epithelial cells of HL. The authors examined 12 cases of HL by transmission electron microscopy to compare the use of a negative staining technique versus routine plastic embedment for the detection of viruses. Herpes-type virions were identified by both methods in 11 cases. One case had negative results for viruses by both methods. Negative staining is a simple and rapid technique that compares favorably with plastic embedment in the detection of herpes-type virions in HL.