Roman Carlos

High incidences of DNA ploidy abnormalities in tongue squamous cell carcinoma of young patients: an international collaborative study

Santos‐Silva A R, Ribeiro A C P, Soubhia A M P, Miyahara G I, Carlos R, Speight P M, Hunter K D, Torres‐Rendon A, Vargas P A & Lopes M A (2011) Histopathology 58, 1127–1135u2028High incidences of DNA ploidy abnormalities in tongue squamous cell carcinoma of young patients: an international collaborative study

High incidence of DNA ploidy abnormalities and increased Mcm2 expression may predict malignant change in oral proliferative verrucous leukoplakia

To assess the DNA content of cases of oral proliferative verrucous leukoplakia (PVL) and correlate the DNA ploidy findings with the expression of Mcm2, geminin, and Ki67, and with clinicopathological data.

Expression of fatty acid synthase (FASN) in oral nevi and melanoma

OBJECTIVEnThe aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions.nnnMATERIALS AND METHODSnExpression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas.nnnRESULTSnFatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression.nnnCONCLUSIONnFatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.

Malignant odontogenic tumors: a multicentric Latin American study of 25 cases.

OBJECTIVEnThe aim of this study was to show the epidemiological features of 25 malignant odontogenic tumors (MOT) in Latin America.nnnMATERIALS AND METHODSnWe retrieved 25 cases of MOT out of 2142 odontogenic tumors, from four oral diagnostic centers in Latin America, and described the main clinical and pathological characteristics.nnnRESULTSnA total of 19 cases were carcinomas, including eight ameloblastic carcinomas, five primary intra-osseous squamous cell carcinomas, three clear cell odontogenic carcinomas and three ghost cell odontogenic carcinomas. All six sarcomas corresponded to ameloblastic fibrosarcoma. Thirteen cases occurred in men and 12 in women, age ranged from 7 to 77 years old, with a mean of 41.4 years. The average age of patients with carcinomas and sarcomas were 48.53 and 19 years old, respectively.nnnCONCLUSIONnAs malignant odontogenic tumors are very rare, this series helps to better clarify their relative frequency, predominant subtypes, and clinical characteristics in Latin America.

Clinicopathological and immunohistochemical features of oral spindle cell carcinoma

BACKGROUNDnOral spindle cell carcinoma (SpCC) is a rare variant of oral squamous cell carcinoma (SCC). The aims of this study were to compare the clinicopathologic and immunohistochemical features of oral SpCC with conventional oral SCC.nnnMETHODSnFive cases of oral SpCC and 10 cases of oral SCC (five well-differentiated and five poorly differentiated) were evaluated through conventional hematoxylin and eosin staining and immunohistochemical reactions to cytokeratins (CK), vimentin, desmin, smooth muscle actin, muscle-specific actin, S-100 protein, epithelial membrane antigen (EMA), p53, and ki-67.nnnRESULTSnOral SpCC showed predilection for males on their sixth decade of life, presenting clinically as painful infiltrative ulcers or ulcerated exophytic polypoid masses, preferably located on the alveolar mucosa. Mesenchymal markers were expressed in the spindle cell but not in the carcinomatous component of SpCC, and it was negative in all SCC. CKs AE1/AE3, 6, 14, and EMA were positive on both carcinomatous and spindle cell components of most SpCCs. These tumors also presented higher p53 and ki-67 expression and no CK 1 expression in contrast to well-differentiated SCC.nnnCONCLUSIONnOral SpCC presented a different clinical profile than conventional SCC and histopathologic features and p53 and ki-67 expression closer to poorly differentiated SCC. Besides mesenchymal markers, CK AE1/AE3, 6, 14, and EMA expression on spindle cells may be useful as an adjunct on microscopical differential diagnosis of SpCC.

Peritrabecular clefting in fibrous dysplasia of the jaws: an important histopathologic feature for differentiating fibrous dysplasia from central ossifying fibroma

OBJECTIVEnThe aim of this multicenter study was to perform a histomorphometric analysis of peritrabecular clefting in fibrous dysplasia (FD) in an attempt to obtain data that could be useful for distinguishing between FD and ossifying fibroma (OF).nnnSTUDY DESIGNnA clinicopathologic analysis was performed in 68 patients diagnosed with FD and 37 patients diagnosed with OF. Histologic sections were scanned using an Aperio ScanScope CS. A histomorphometric analysis was performed with the aid of an image analyzer (UTHSCSA Image Tool 3.0 version) on 37 randomly selected samples of FD, and the results were compared with the 37 OF specimens.nnnRESULTSnThe presence of peritrabecular clefting was observed in 32 (86.5%) cases of FD, whereas no case of OF presented peritrabecular clefting.nnnCONCLUSIONSnPeritrabecular clefting may be a hallmark of the lesions in patients with FD, and it may be a valuable microscopic feature for distinguishing it from OF.

Assessing the contribution of HRPT2 to the pathogenesis of jaw fibrous dysplasia, ossifying fibroma, and osteosarcoma.

OBJECTIVEnTo investigate HRPT2 in jaw ossifying fibroma (OF), fibrous dysplasia (FD), and osteosarcoma (OS).nnnSTUDY DESIGNnWe combined microsatellite loss of heterozygosity (LOH), HRPT2 sequence alterations at the mRNA level by reverse-transcription polymerase chain reaction (PCR), cDNA sequencing, and quantitative PCR (qPCR) and immunohistochemistry (IHC) in a total of 19 OF, 15 FD, and 9 OS. Because HRPT2 (parafibromin) interacts with cyclin D1, we investigated cyclin D1 expression with the use of qPCR and IHC.nnnRESULTSnLOH was detected in 3/5 FD, 6/9 OF, and 2/2 OS heterozygous samples. LOH was not associated with decreased mRNA levels or HRPT2 protein expression except for 1 OF which harbored an inactivating mutation. However, this tumor did not display altered transcription or protein levels of HRPT2 nor cyclin compared with the other OF.nnnCONCLUSIONSnThe contribution of HRPT2 inactivation to the pathogenesis of OF, FD, and OS is marginal at best and may be limited to progression rather than tumor initiation.

Epstein–Barr Virus and Human Herpes Virus-8 are not Associated with Juvenile Nasopharyngeal Angiofibroma

Background Nasopharyngeal angiofibroma (also known as juvenile nasopharyngeal angiofibroma) is a rare fibroblastic tumor with a vascular component that occurs in the nasopharynx and posterolateral nasal wall of adolescent boys. The etiology of nasopharyngeal angiofibroma remains elusive. This investigation was undertaken to determine if human herpes simplex virus-8 and Epstein–Barr virus are possible etiologic viruses and to determine if they have any association with the age of the patient and/or the proliferative state of the lesion. Materials and methods Formalin fixed, routinely processed, and paraffin embedded surgical specimens of 15 angiofibromas were submitted to PCR for EBV and HHV-8, while inxa0situ hybridization was also employed for EBV. Immunohistochemical analysis for ki-67 was performed using MIB immunostaining. Results None of the tumors were positive for HHV-8. The PCR technique produced a false positive reaction in five cases, with all cases non-reactive with EBV-ISH. The age of the patients did not show correlation with the Ki-67 labeling index. Conclusion Angiofibroma does not appear to be associated with either HHV-8 or EBV, thereby excluding these viruses as potential etiologic agents. The lack of a correlation between the proliferative index and the age of the patient suggests the proposed puberty induced, testosterone-dependent tumor growth may not play a significant role in tumor development.

Stromal myofibroblasts in squamous cell carcinoma of the tongue in young patients - a multicenter collaborative study.

OBJECTIVEnThe purpose of this study was to evaluate the presence of myofibroblasts, frequently associated with a more aggressive neoplastic behavior, in oral tongue squamous cell carcinoma (TSCC) of young patients and to compare with the distribution observed in older patients.nnnSTUDY DESIGNnTumor samples from 29 patients younger than 40 years old affected by TSCC were retrieved and investigated for the presence of stromal myofibroblasts by immunohistochemical reactions against α smooth muscle actin, and the results obtained were compared to TSCC cases affecting older patients.nnnRESULTSnNo positive reaction could be found in the stromal areas devoid of neoplastic tissue, whereas myofibroblasts were present in 58.6% of the lesions in young patients and in 75.9% of the older ones. No significant difference was found when comparing the invasive front and the overall stroma of both groups, and no correlation could be obtained with stromal α smooth muscle actin expression, higher tumor grades or clinical stage (P > .05).nnnCONCLUSIONnThere was no significant difference between the presence of stromal myofibroblasts of TSCC affecting young and old individuals.

Primordial odontogenic tumor: Subepithelial expression of Syndecan-1 and Ki-67 suggests origin during early odontogenesis

Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation. Ki-67 is considered the gold standard as a cell proliferation marker. The aim of this study was to examine the expression of Syndecan-1 and Ki-67 proliferation index in POT and normal tooth germs to better understand the biological behavior of this tumor. Results showed that Syndecan-1 was more intensely expressed in subepithelial mesenchymal areas of POT, in a pattern that resembles the early stages of tooth development. The cell proliferation index (4.1%) suggests that POT is a slow growing tumor. Syndecan-1 expression in tooth germs in late cap and early bell stages was similar to POT, showing immunopositivity in subepithelial mesenchymal condensed areas. The immunohistochemical findings showed a pattern in which the population of subepithelial mesenchymal cells exhibited greater proliferative activity than the central portion of the dental papilla.