Immunohistochemical Expression of Fatty Acid Synthase (FASN) is Correlated to Tumor Aggressiveness and Cellular Differentiation in Salivary Gland Carcinomas.

Fatty acid synthase (FASN) expression is closely related to cancer progression, in particular, tumor aggressiveness and poor prognosis. This study aimed to analyse the expression of FASN in carcinomas of the salivary glands and correlate it with Ki-67 expression. We analysed by immunohistochemistry the expression of FASN and Ki-67 on tissue sections from 7 cases of adenocarcinoma, not otherwise specified (AdNOS), 6 cases of polymorphous adenocarcinoma (PAC), 16 cases of acinic cell carcinoma (AcCC), 19 cases of adenoid cystic carcinoma (AdCC), 15 cases of epithelial-myoepithelial carcinoma (EMC); 10 cases of secretory carcinoma (SC), 13 cases of mucoepidermoid carcinoma (MEC), 10 cases of salivary duct carcinoma (SDC) and 7 cases of myoepithelial carcinoma (MC). These carcinomas were classified into aggressive and indolent regarding their biological behaviour. Additionally, MEC and AdCC were also classified according to the histological grade. High expression of FASN was found in SDC (100%), SC (100%), AcCC (68.7%) and AdNOS (57.2%). No association was found between FASN and Ki-67 expression. Aggressive carcinomas showed a higher rate of Ki-67 proliferation (p < 0.001) and greater expression of FASN when compared to indolent carcinomas (p < 0.05). With regards to carcinomas categorized as indolent, FASN expression was much higher in the lesions that presented cell differentiation (SC and AcCC). Also, FASN expression was significantly higher in high-grade AdCC and MEC when compared to low-grade tumors (p < 0.05). We concluded that FASN expression was correlated to tumor aggressiveness and cellular differentiation in salivary gland carcinomas.

Evaluation of a subset of tumor suppressor gene for copy number and epigenitic changes in pleomorphic adenoma and carcinoma ex-pleomorphic adenoma carcinogenesis.

OBJECTIVE: The progression of pleomorphic adenoma (PA) to carcinoma ex-pleomorphic adenoma (CXPA) encompasses several genomic alterations involving complex pathways. Tumor suppressor genes seem to play important roles in the tumorigenesis of both tumors. The aim of this study was to evaluate copy number and methylation of tumor suppressor genes' status in PA and CXPA samples. STUDY DESIGN: Eight cases of PA, 2 cases of residual PA in CXPA, and 5 cases of CXPA were studied; the latter were classified according to invasiveness and histopathological subtype. Changes in 41 tumor suppressor genes were evaluated by multiplex ligation-probe dependent amplification analysis. RESULTS: Copy number losses of CASP8, MLH1, and RARB genes were associated with PA and CXPA, while KLK3 and AI69125 copy number losses were exclusive to CXPA. The sarcomatoid carcinoma showed more copy number alterations compared with other subtypes. Hypermethylation of RASSF1 was found mainly in PA and less frequently in malignant tumors. CONCLUSIONS: CASP8, MLH1, and RARB tumor suppressor genes were altered by copy number losses during PA progression to CXPA. Lastly, RASSF1 inactivation by methylation was also detected in both tumors.

PLAG1 expression is maintained in recurrent pleomorphic adenoma.

The proto-oncogene (pleomorphic adenoma gene 1 (PLAG1)) is immunohistochemically overexpressed in pleomorphic adenoma (PA). Its expression in recurrent pleomorphic adenoma (RPA), however, has not been investigated. Since complex mechanisms are involved in tumor recurrence, the aim of this study was to investigate whether PLAG1 overexpression occurs in RPA. We studied PLAG1 protein expression in 40 PAs and 36 RPAs by immunohistochemistry. Cases with immunopositive cells were classified into two categories, between 10 and 50 % and >50 %. In both groups, PLAG1 expression was observed in both epithelial and myoepithelial cells. Of PAs, 37 cases (93 %) were positive, while this was the case in 34 RPA cases (94 %). Our findings suggest that in addition to morphological similarity, PA and RPA express PLAG1, which might play a role in tumor recurrence. Furthermore, as for PA, expression of PLAG1 can be considered a valuable diagnostic marker for RPA.

Primary synovial sarcoma involving the submandibular gland.

Synovial sarcoma represents 5.6%-10% of all soft-tissue sarcomas. Adolescents and young adults are most frequently affected, mainly in the deep soft tissue of the extremities. Only 10% of synovial sarcomas affect the head and neck region; most of these are biphasic. We describe a case of an 18-year-old man who complained of a mass in the right submandibular region that had been present for approximately 12 months. On surgical removal, microscopic analysis showed a tumor formed by sheets of malignant spindle cells involving the submandibular gland. Immunohistochemistry displayed positivity for AE1/AE3, CK18/8, epithelial membrane antigen, CD99, CD56, and TLE-1. Based on these immunohistochemical and histopathologic features, a diagnosis of monophasic synovial sarcoma was rendered. The patient was treated with adjuvant radiotherapy and after 1 year was free of disease. To the best of our knowledge, this is the first reported case of synovial sarcoma involving the submandibular gland.

Single oral paracoccidioidomycosis mimicking other lesions: report of eight cases.

Paracoccidioidomycosis is a fungal infection caused by Paracoccidioides brasiliensis. It is an endemic disease, representing a serious health problem in Latin American countries. This infection primarily affects the lungs and is acquired by inhalation of the fungus. It can spread to other organs and tissues, mainly the oral cavity affecting more adult men from 30 to 50 years of age. On clinical presentation, several signs associated with impaired general and nutritional conditions can be noted. Oral manifestation is more common in the soft palate, gingiva, lower lip, buccal mucosa, and tongue. The classical clinical presentation is a superficial ulcer with granular appearance and hemorrhagic points. Usually, the oral lesion is extensive and generalized. Although uncommon, when the oral manifestation is single, others lesions, particularly squamous cell carcinoma, must be included in the differential diagnosis. In this article, the authors discuss the unusual presentation of eight cases of single oral paracoccidioidomycosis and its diagnostic importance.