Histopathological Grading and Clinical Features of Patients with Mucoepidermoid Carcinoma of the Salivary Glands
Department of Otolaryngology, Akita University School of Medicine, Akita. Nippon Jibiinkoka Gakkai Kaiho
03/2003; 106(3):192-8. DOI: 10.3950/jibiinkoka.106.192
In the 22 years between March 1979 and February 2001, we treated 16 patients--10 men and 6 women aged 10-80 years (mean: 44 years)--with mucoepidermoid carcinoma (MEC) of the salivary gland, evaluating them clinically and histopathologically. Tumor sites included 12 at the parotid gland, 3 at the submandibular gland, and 1 at the minor salivary gland. All tumors were graded histopathologically based on the criteria of Goode et al. as follows: low grade (n = 10), intermediate grade (n = 1), and high grade (n = 5). Female gender was associated with low grade MEC and male gender with high grade MEC (P < 0.05). The age at onset in high grade MEC was older than that in low grade MEC (P < 0.005). Lymph-node metastasis was detected in 7 out of the 16 patients (44%) associated significantly with high grade MEC (P < 0.05). Distant metastasis was detected in 4 of 16 patients (25%). Distant metastasis was significantly associated with high grade MEC (P < 0.05). Local recurrence was detected in 3 of 15 patients undergoing surgery (20%). No difference was seen in local recurrence frequency between low and high grade MEC. Survival was calculated with Kaplan-Meier's method. In all 16, 5-year survival was 86% and 10-year survival 75%. Five-year survival in low grade MEC was 100%, whereas that in high grade MEC was 67% (P < 0.05). In MEC of the salivary gland, it was suggested that the histopathological MEC grade evaluated by Goode's criteria significantly correlated with gender, age, lymph-node metastasis, distant metastasis, and 5-year survival.
Available from: Somboon Keelawat
- "After, each slide underwent, histopathological evaluation by three independent pathologists (SK, KD and NK), and those cases correctly identified as MECs were histologically graded according to the WHO diagnostic criteria . The MEC samples assessed yielded low (n=12), intermediate (n=9) and high-grade (n=3) samples based on the 5 histological features (the presence of a cystic component, neural invasion, necrosis, mitotic activity and anaplasia) [1,6,43,44]. For the control group, normal salivary gland tissues were obtained (n=14) from patients undergoing radical neck dissections. "
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Mucoepidermoid carcinoma (MEC) can be classified into low-, intermediate-, and high-grade tumors based on its histological features. MEC is mainly composed of three cell types (squamous or epidermoid, mucous and intermediate cells), which correlates with the histological grade and reflects its clinical behavior. Most cancers exhibit reduced methylation of repetitive sequences such as Long INterspersed Element-1 (LINE-1) and Alu elements. However, to date very little information is available on the LINE-1 and Alu methylation status in MEC. The aim of this study was to investigate LINE-1 and Alu element methylation in MEC and compare if key differences in the methylation status exist between the three different cell types, and adjacent normal salivary gland cells, to see if this may reflect the histological grade.
LINE-1 and Alu element methylation of 24 MEC, and 14 normal salivary gland tissues were compared using Combine Bisulfite Restriction Analysis (COBRA). Furthermore, the three different cell types from MEC samples were isolated for enrichment by laser capture microdissection (LCM), essentially to see if COBRA was likely to increase the predictive value of LINE-1 and Alu element methylation.
LINE-1 and Alu element methylation levels were significantly different (p<0.001) between the cell types, and showed a stepwise decrease from the adjacent normal salivary gland to the intermediate, mucous and squamous cells. The reduced methylation levels of LINE-1 were correlated with a poorer histological grade. In addition, MEC tissue showed a significantly lower level of LINE-1 and Alu element methylation overall compared to normal salivary gland tissue (p<0.001).
Our findings suggest that LINE-1 methylation differed among histological grade mucoepidermoid carcinoma. Hence, this epigenetic event may hold value for MEC diagnosis and prognostic prediction.
BMC Clinical Pathology 03/2013; 13(1):10. DOI:10.1186/1472-6890-13-10
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ABSTRACT: Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of salivary glands with a widely diverse biologic behavior that is correlated with the histological grade of the tumor. The purpose of this study was to evaluate the clinical outcomes of MEC of minor salivary glands in a group of 16 patients, who were treated in our clinic, and to discuss the management of this carcinoma.
Between 1985 and 2000, 16 patients with MEC of minor salivary glands were treated in the Clinic of Oral and Maxillofacial Surgery of the 'G. Papanikolaou' General Hospital, in Thessaloniki. The age range was 16-65 years. The distribution of the primary sites was: hard plate (one), soft palate (two), hard and soft palate (three), hard and soft palate with spread in paranasal sinus and nasal cavity (one), buccal mucosa (three), hard palate, alveolar process and buccal mucosa (two), and retromolar triangle (our). The tumors were clinically staged according to the tumor nodes metastase (TNM) system (Seifert, 1991). All patients were treated radically with surgery. The surgery was combined with radiotherapy in nine patients. Radiotherapy was delivered using Co-60. Doses ranged from 50 to 60 Gy and the duration of the therapy ranged from 25 to 35 days. Immunohistochemical assay of the expression of the Ki-67 antigen was performed on a subset of 15 cases.
The mean follow-up range was 4-14 years. From the 16 patients with MECs 10 (62.5%) were alive and five (35.6%) had died from the disease. Four patients were free of the disease for more than 5 years (range 8-14), five patients were free of the disease for 5 years and one patient was free of the disease for 4 years. One patient lived more than 10 years and died from another cause. Local recurrence developed in one patient 10 years after the initial treatment. Lymph node metastases occurred in one patient within the first year after the initial surgical treatment. Distant metastases (two in bones and one in lungs) occurred in three patients within 2 years after completing the treatment. The Pearson chi-square statistical analysis was used for comparing the Ki-67 values in correlation with histological grade of the tumors. The Ki-67 expression was only 1% in low-grade MECs, while in intermediate-grade tumors it was estimated between 3 and 4%. The high-grade tumors had increased expression (10%) of tumor cells.
Complete surgical excision is the treatment of choice for MECs. Adequate excision is important in all grades of tumors. Prognosis of MECs is a function of the histological grade, adequacy of excision and clinical staging. The immunohistochemical study of Ki-67 expression may provide additional prognostic information for this tumor.
Oral Diseases 08/2006; 12(4):364-70. DOI:10.1111/j.1601-0825.2005.01166.x · 2.43 Impact Factor
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ABSTRACT: The biologic behavior and factors influencing the development of salivary gland mucoepidermoid carcinoma are not fully understood. Alteration of the cyclin-dependant kinase inhibitor p21(WAF) could cause uncontrolled proliferation leading to cancer. Thirty-five mucoepidermoid carcinomas were graded and immunohistochemically stained for p21(WAF). The percentage of positive tumor cells was determined using an eyepiece graticule and a computer-assisted image analyzer, which revealed 8.6% and 22.9% of the cases to be positive for p21(WAF), respectively. A statistically significant correlation was not observed between p21(WAF) and grading. Considering the absence of p21(WAF) expression in most mucoepidermoid carcinomas, it appears that the inhibitory effect of p21(WAF) on cell growth is removed in most cases. Given the lack of correlation with tumor grade, it is possible that the impact of p21(WAF) is in the earlier stages of tumorigenesis. A p53-independent pathway of p21(WAF) induction may exist for the small proportion of tumors that showed positivity.
International Journal of Surgical Pathology 02/2007; 15(1):6-13. DOI:10.1177/1066896906295915 · 0.95 Impact Factor
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