RESUMO
BACKGROUND: Research methodology in oral and maxillofacial pathology has illimitable potential. The tissue processing involves many steps of which one of the most important step is "Clearing," which is a process of replacing dehydrant with a substance which is miscible with embedding medium or paraffin wax. Xylene is one of the common clearing agents used in laboratory, but it is also hazardous. The main aim of this study is to substitute conventionally used xylene by a mixture of kerosene and xylene in clearing steps without altering the morphology and staining characteristics of tissue sections. This will also minimize the toxic effects and tend to be more economical. MATERIALS AND METHODS: One hundred and twenty bits of tissue samples were collected, each randomly separated into 4 groups (A, B, C and D) and kept for routine tissue processing till the step of clearing; during the step of clearing instead of conventional xylene, we used mixture of xylene and kerosene in 4 ratios ([A-K:X - 50:50]; [B-K:X - 70:30]; [C - Ab. Kerosene]; [D - Ab. Xylene - as control]) and observed for the light microscopic study adopting H and E staining, IHC (D2-40), Special stains (periodic acid-Schiff and congo red) procedure. The result was subjected to statistical analysis by using Fisher's exact test. RESULTS: The results obtained from the present study were compared with control group, i.e., D and it was observed that Groups A and B were absolutely cleared without altering the morphology of tissue and cellular details; optimum embedding characteristics and better staining characteristics were also noted, whereas Group C presents poor staining characteristics with reduced cellular details. Embedded tissues in Group C presented with rough, irregular surface and also appeared shrunken. CONCLUSION: Combined mixture of xylene and kerosene as a clearing agent in different ratio, i.e., Group A (K:X - 50:50) and B (K:X - 70:30) can be used without posing any health risk or compromising the cellular integrity.
RESUMO
Myoepithelial carcinoma (MC) is a malignant salivary gland neoplasm whose tumor cells demonstrate cytologic differentiation toward myoepithelial cells and lack ductal or acinar differentiation. It is a relatively rare tumor and many a times remains undiagnosed because of histopathological heterogeneity. It represents about 0.4-0.6% of all salivary gland tumors and 1.2-1.5% of carcinomas. It occurs predominantly in the parotid gland with a mean age of presentation being 55 years (range 14-86) with no sex predilection. MC appears to be a low grade malignancy when arising in a pleomorphic adenoma, but tends to be more aggressive and has a higher metastatic potential when arising de novo. The clinical behavior of MC is variable and there are no pathologic features that correlate with patients' outcome. Most tumors that display marked cytologic atypia, high mitotic activity and necrosis tend to behave aggressively. The current case is of a 42-year-old male with recurrent tumor mass in the mandibular right posterior region. The purpose of this article was to describe the clinicopathological and immunohistochemical features of intraoral MC and to discuss review of literature of this rare tumor.
