Recurrent central odontogenic fibroma in a patient with nevoid basal cell carcinoma syndrome: case report and in vitro analysis.

OBJECTIVE: Central odontogenic fibromas (COF) are rare, benign tumors derived from dental mesenchymal tissue that may occur in the maxilla or mandible. This report describes primary and recurrent COF in the mandible of a patient with nevoid basal cell carcinoma syndrome (NBCCS). STUDY DESIGN: A 36-year-old African American male presented with a COF and its recurrence 17 months later. Tissue pieces were obtained from both occurrences with IRB-approved signed consent. Collected tissue pieces were dissected; one portion was formalin-fixed and paraffin-embedded, and the other was cultured for the isolation of cell populations from the primary (COdF-1) and recurrent (COdF-1a) tumors. Quantification real-time polymerase chain reaction (qRT-PCR), immunohistochemistry, and DNA sequencing were used for gene and protein analysis of the primary tumor and cell populations. RESULTS: Histopathologic analysis of the tumor showed sparse odontogenic epithelial cords in fibrous connective tissue, and qRT-PCR analysis of tumor and cell populations (COdF-1 and COdF-1a) detected VIM, CK14, CD34, CD99 and ALPL mRNA expression. Protein expression was confirmed by immunohistochemistry. CD34 expression in primary tissues was higher than in tumor cells due to tumor vascularization. DNA sequencing indicated the patient had PTCH1 mutations. CONCLUSIONS: Histopathology, mRNA, and protein expression indicate the rare occurrence of COF in a patient with mutated PTCH1 gene and NBCCS.

Mandibular undifferentiated pleomorphic sarcoma: Molecular analysis of a primary cell population.

BACKGROUND: Undifferentiated pleomorphic sarcomas are one of the most common subtypes of soft tissue sarcomas. These are aggressive mesenchymal tumors and are devoid of the major known biomarkers except vimentin. Our objective was to establish and characterize a primary cell population from a mandibular UPS specimen. METHODS: The tumor was surgically removed from the right mandible of a 24-year-old male with IRB approved signed consent. Tumor was dissected, cultured ex vivo, and a cell population, MUPS-1, were isolated from outgrowths. Gene and protein expression profiles of both the primary tumor and the derived there from cells were obtained by quantitative RT-PCR and immunohistochemistry and included markers of epithelial, endothelial, and mesenchymal differentiation. To better define potential biomarkers, MUPS-1 cells were additionally characterized by RNA sequencing analysis. RESULTS: Pathological analysis of primary tumor tissue revealed a sarcoma demonstrating multiple pathways of differentiation simultaneously with myxoid, fibrous, and osseous tissue. The isolated cells had a spindle cell-like morphology, were maintained in culture for greater than 20 passages, and formed colonies in soft agar indicating tumorigenicity. The cells, similar to the primary tumor, were strongly positive for vimentin and moderately expressed alkaline phosphatase. RNA-seq analysis revealed the tumor over-expressed several genes compared to normal tissue, including components of the Notch signaling pathway, NOTCH3 and JAG1. CONCLUSIONS: We have successfully established an undifferentiated pleomorphic sarcoma cell population, which will provide a valuable resource for studying fundamental processes and potentially serving as a platform for exploring therapeutic strategies for sarcomas.

Features of peri-implantitis associated with luting cement extrusion: a histopathologic report in humans.

OBJECTIVE: To describe and illustrate the histologic characteristics of luting cement-induced peri-implantitis in the posterior maxilla of a 56-year-old man. CASE PRESENTATION: A dental implant inserted 6 years previously in the maxillary left first premolar region revealed pus and swelling. A periapical radiograph showed severe bone loss around the dental implant, and the presence of surrounding residual particles of luting cement. The implant was removed with its adjacent tissues. The harvested implant was fixed in formaldehyde solution (formalin). A 4-mm fragment of soft tissue and a 6-mm fragment of bone were cut from the implant specimen and submitted for routine processing of hematoxylin-eosin (h&e) slides for histologic analysis. The implant specimen was processed and embedded in glycol methacrylate resin and ground to a thickness of 50 µm for histologic examination. RESULTS: The microscopic examination of the h&e slides showed connective tissue with an inflammatory infiltrate composed of histiocytes, lymphocytes, and plasma cells. There was a fragment of viable bone integrated with the bone graft material. The bone showed evidence of active resorption by osteoclasts in Howship lacunae. The implant sections showed trabecular bone with lamellar structure in the apical portion. Foreign body, compatible with luting cement, was present in the coronal portion, adjacent to the threads of the implant, as well as osteoclasts in Howship lacunae. CONCLUSION: This report, documenting a case of peri-implantitis associated with excess cement extrusion, revealed that that the bone loss was associated with an inflammatory infiltrate. Additional studies focusing on the histopathologic characteristics of peri-implantitis could help to increase the knowledge of peri-implant disease to shed light on prevention and treatment.

GBR using cross-linked collagen membrane and a new highly purified bovine xenograft (Laddec) in horizontal ridge augmentation: Case report of clinical and histomorphometric analysis.

This case report presents the clinical and histologic evaluation of the application of a cross-linked collagen membrane and a new highly purified bovine xenograft with type 1 collagen fiber preservation (Laddec) in mandibular horizontal ridge augmentation on a 50-year-old woman. Significant bone volume was achieved to restore severe bone defect in order to place two implants. Histomorphometric analysis of a bone core at the augmented site, at 6 months, showed new bone formation with bone substitute particles integrated to new viable bone.

Establishment and characterization of a primary calcifying epithelial odontogenic tumor cell population.

UNLABELLED: Calcifying epithelial odontogenic tumors (CEOTs) are rare neoplasms derived from dental tissue with the unique characteristic of calcifying amyloid-like material. OBJECTIVES: To establish primary CEOT epithelial-derived cell populations, investigate the expression of enamel matrix proteins (EMPs), and identify potential ameloblastin (AMBN) and patched 1 (PTCH1) gene alterations. MATERIALS AND METHODS: A 28-year-old patient with a lesion of the posterior maxilla, radiographically characterized by a radiolucency with well-defined borders containing mixed radiopacities, agreed to participate with informed consent. The patient's biopsy confirmed the diagnosis of CEOT, and a small representative tumor fragment was ascertained for cell culture. Explant cultures were established and used to establish primary cell populations. These were analyzed for morphology, cell proliferation, mineralization activity, expression of epithelial-associated markers (qRT-PCR and immunocytochemistry), and gene mutations of AMBN or PTCH1. DNA was extracted from tumor cells and gene coding and exon-intron boundaries overlapping fragments amplified. PCR products were bidirectional DNA sequenced and compared against reference sequence. RESULTS: A CEOT cell population was established and proliferated in culture and could be maintained for several passages. Expression of EMPs, cytokeratin 14 and 17, and patched (PTCH1), as well as ALP activity, was detected. These cells also had the ability to mineralize, similar to the primary tumor. Two AMBN alterations were identified in the sample: c.1323G>A/A441A (rs7680880) and c.1344*+111delA. Two single-nucleotide polymorphisms were identified in the PTCH1 gene. CONCLUSIONS: Our data support the establishment of a CEOT-derived cell population, which expresses known epithelial-associated proteins.

Targeting the sonic hedgehog pathway in keratocystic odontogenic tumor.

Keratocystic odontogenic tumors (KCOT) may occur sporadically or associated with the nevoid basal cell carcinoma syndrome. It is a benign aggressive tumor of odontogenic epithelial origin with a high rate of recurrence. A primary human keratocystic odontogenic tumor cell population, KCOT-1, has been established from a tumor explant culture. The KCOT-1 cells were characterized by growth rate, gene expression profiles of major tooth enamel matrix proteins (EMPs), amelogenin (AMELX), enamelin (ENAM), ameloblastin (AMBN), amelotin (AMTN), tumor-related proteins enamelysin (MMP-20), kallikrein-4 (KLK-4), and odontogenic ameloblast-associated protein (ODAM) using quantitative real-time reverse transcription-polymerase chain reaction. Cytokeratin 14 (CK14) was examined by immunohistochemistry. In addition, expression of the members of the sonic hedgehog (SHH) pathway, SHH, patched (PTCH-1), smoothened (SMO), GLI-1, and GLI-2 and of the NOTCH signaling pathway, NOTCH-1, NOTCH-2, NOTCH-3, JAG-2 (Jagged-2), and Delta-like-1 (DLL-1) were evaluated. KCOT-1 cells were treated with SMO antagonist cyclopamine. We found that cyclopamine significantly arrested the growth of KCOT-1 cells in a dose-dependent manner and that the effects of cyclopamine were abolished by adding SHH protein. The protein expression of the SHH pathway was down-regulated by cyclopamine, further confirming that cyclopamine inhibits the SHH signaling pathway; SHH down-regulation correlated with the down-regulation of the NOTCH signaling pathway as well. In conclusion, using an established KCOT-1 cell population, we characterized the gene expression profiles related to the EMPs, SHH, and NOTCH signaling pathway and confirmed that cyclopamine significantly arrested the growth of KCOT-1 cells and may be a viable agent as a novel therapeutic.

Physical effects of sodium hypochlorite on bone: an ex vivo study.

INTRODUCTION: Sodium hypochlorite (NaOCl) accidents during endodontic therapy require accurate and prompt action. Understanding the physical properties of bone and evaluating the resultant cell damage from NaOCl exposure could improve management of these accidents. This study assessed the physical and histologic properties of dog femurs exposed to NaOCl for a period of 30 minutes. METHODS: Four dog femurs were dissected and frozen. Twelve 40-mm-long sections were obtained and cut into 20-mm paired sections. Adjacent surfaces were randomly selected for shallow injection of either NaOCl or saline. Sections were visually assessed for gross physiologic effects. The structural integrity of the cancellous bone was measured by micro-indentation testing, and statistical analysis of needle penetration was conducted. Histologic evaluation of specimens was also conducted. RESULTS: Grossly, NaOCl caused remarkable changes in cancellous structure, leaving craters of apparent demineralization. There was a significant difference in mean depth of needle penetration and demineralization between the treatments (P = .0397), with NaOCl showing greater mean depth than saline. The NaOCl group showed degradation of the organic matrix collagen. CONCLUSIONS: These results indicate that NaOCl compromises the integrity of cancellous bone. Calcified elements, especially cortical bone, appeared less affected.

Merkel cell carcinoma: correlation of KIT expression with survival and evaluation of KIT gene mutational status.

Merkel cell carcinoma is one of the most aggressive primary cutaneous malignancies. Because some Merkel cell carcinomas express the receptor tyrosine kinase KIT, we aimed to evaluate the correlation of KIT expression with the outcome and the presence of activating mutations in the KIT gene in Merkel cell carcinoma. A total of 49 tumors from 40 patients with a diagnosis of Merkel cell carcinoma were identified, of which 30 cases from 21 patients were used in the study. KIT expression was assessed by immunohistochemistry on formalin-fixed, paraffin-embedded material. Cases were divided into low expressors (0-1+ staining intensity) and high expressors (2-3+ staining intensity). Direct sequencing of exons 9, 11, 13, 17, and 18 of the KIT gene spanning the extracellular, juxtamembrane, and tyrosine kinase domains was performed for cases with high KIT expression. Thirty tumors from 21 patients were analyzed for KIT expression. High KIT expression was seen in 67% of the patients. Five-year survival rates in tumors expressing high versus low levels of KIT were 0% versus 57.8%, respectively; however, this dramatic difference did not reach statistical significance (P = .07). A total of 4 point mutations were identified in 18 tumors analyzed. Two of these were silent mutations involving exons 17 and 18, and 2 involved intron 16-17. Two of the identified mutations may represent novel polymorphisms. Our work suggests a correlation between KIT expression and a worse prognosis in Merkel cell carcinoma patients, raising the possibility of an active role of this receptor in tumor progression and metastasis. However, we did not identify KIT activating mutations in any of the tumors analyzed.

Keratocystic odontogenic tumor associated with nevoid basal cell carcinoma syndrome: similar behavior to sporadic type?

OBJECTIVE: The objective of this study was to analyze the expression of proliferative markers and p53 in keratocystic odontogenic tumor (KCOT) sporadic type and KCOT associated with nevoid basal cell carcinoma syndrome (NBCCS). STUDY DESIGN AND SETTING: We performed a cross-sectional study. A total of 19 patients with KCOT were selected from the Oral Pathology Laboratory archives, Central University of Venezuela, from 1995 to 2005. SUBJECTS AND METHODS: Twelve cases corresponded to sporadic KCOT, and seven cases were associated with NBCCS. Immunohistochemical analysis for p53, proliferating cell nuclear antigen (PCNA), and Ki-67 was performed in all 19 cases. RESULTS: Of the seven cases associated with NBCCS, six (86%) were positive for PCNA. From the 12 sporadic cases, nine (75%) were positive for PCNA. Only one case of sporadic KCOT showed Ki-67 positivity. Five of 12 (42%) cases of sporadic KCOT were positive for p53, and only one (14%) case associated with NBCCS was positive for p53. CONCLUSION: On the basis of the analysis of the expression of PCNA, Ki-67, and p53, there appears to be no evidence to indicate higher aggressiveness in growth and infiltrative behavior in syndromic KCOT compared with the sporadic type. Therefore, surgical treatment may be approached in the same manner in KCOT sporadic and syndromic with the goal of minimizing recurrence.

Lymphedematous fibroepithelial polyps of the penis associated with long-term condom catheter use: case report and review of the literature.

Lymphedematous fibroepithelial polyps of the penis are lesions that have only recently been described and are frequently associated with condom catheter use. We report an additional case of lymphedematous fibroepithelial polyps of the penis in association with long-term condom catheter use in a 36-year-old man. Local excision showed large polypoid nodules with compact orthohyperkeratosis and mild acanthosis. The stroma was hypercellular with spindled to stellate fibroblasts and occasional multinucleated cells. Proliferation of small linear to slightly arcuate vessels with some superficial dilatation was a prominent feature. Focal expression of smooth muscle actin and desmin was present in the stroma. Lymphedematous fibroepithelial polyps of the penis are rare lesions with only 11 cases previously reported. We present here an additional example of this entity to highlight the differential diagnosis, the association with condom catheter use and to raise awareness for this unusual diagnosis.

Cystinosis, Fanconi syndrome, and odontogenic cysts.

Cystinosis is a multisystemic genetic storage disorder characterized by a mutation in the transporter system of cystine. The disease particularly affects the renal system by causing deposition of cystine crystals leading to, if untreated, Fanconi syndrome and end-stage renal disease. This disease also affects the ocular system, central nervous system, endocrine system, hepatobiliary system, and musculoskeletal system. We present the first case of cystine crystal deposition within an odontogenic cyst, confirmed by the correlation of the clinical, radiographic, and histologic findings on this patient.

Calretinin expression in the differential diagnosis of human ameloblastoma and keratocystic odontogenic tumor.

Ameloblastoma is a benign, locally aggressive epithelial odontogenic tumor that has the potential to become malignant and produce metastasis to distant sites such as lungs and kidneys. The histologic presentation can be, in some instances, mistaken for keratocystic odontogenic tumor (KCOT) (formerly known as odontogenic keratocyst). The expression of calretinin [calbindin2 (CALB2)] was investigated on both ameloblastoma and KCOT. Nineteen cases of ameloblastoma and 17 cases of KCOT were stained with calretinin antiserum 18-0211 (Zymed, San Francisco, CA). All cases (100%) of ameloblastoma showed positive calretinin staining, restricted to the neoplastic epithelial component and none (0%) of the 17 KCOTs showed positive calretinin staining. Gene expression profiling of ameloblastomas showed CALB2 expressed in the basal cell layer of columnar cells resembling preameloblasts, in all 5 of the ameloblastomas evaluated. Taken together, the results of this study strongly support calretinin as a useful immunohistochemical marker for ameloblastoma and malignant ameloblastoma and it can also be used in the differential diagnosis of KCOT.