Immunohistochemical evaluation of superficial and invasive front of oral squamous cell carcinoma using epithelial membrane antigen as a marker.

Background: Epithelial membrane antigen (EMA) has been used as a marker for the expression of tumour margins in various glandular neoplastic lesions. Histopathologically, oral squamous cell carcinoma (OSCC) may exhibit several features within the same tumour cells, portraying that these cells at the invasive margins commonly display certain features that differ from those of the superficial part of the tumour. Aim: To identify and study the invasive tumour front and also to recognise any micrometastases in an OSCC lesion. Materials and Method: A retrospective study of 30 OSCC cases with superficial and most invasive parts were sectioned at 4 µm. Routine H&E staining and immunohistochemical staining with mouse antihuman EMA were done. The OSCC cases were graded into well differentiated squamous cell carcinoma (WDSCC), moderately differentiated squamous cell carcinoma (MDSCC) and poorly differentiated squamous cell carcinoma (PDSCC). The EMA-stained slides were observed and analysed under higher magnification to identify the individual EMA-stained cells. Results: Analysis of Variance (ANOVA) analysis revealed that when comparing the superficial and invasive fronts of OSCC, it was evident that the P values were significant across the groups. In WDSCC, positive predictive value was 70.6% and sensitivity was 100% when the same slide was analysed for large and small islands to individual cells in an EMA-stained section, while MDSCC and PDSCC showed both sensitivity and positive predictive value to be 100%. Conclusion: EMA could be considered a useful prognostic marker for describing the nature of the neoplastic epithelium as well as recognising the typical anaplastic cells in cases of OSCC.

Evaluation and comparison of the efficacy of coconut oil as a clearing agent with xylene.

Background: Xylene is a routinely used clearing agent in histopathology. It is potentially toxic and flammable in nature. Histotechnicians are routinely exposed to this hazardous chemical. Because xylene is used so pervasively in histopathology, it has always been a concern for pathologists and laboratory workers, as its regular and prolonged exposure have serious health effects. Considering its toxicity, different biocompatible xylene substitutes have been evaluated. Aim and Objectives: This study was conducted to evaluate the efficacy of coconut oil as a clearing agent and compare with xylene. Materials and Methods: Two equal halves of 45 soft-tissue specimens were processed simultaneously in xylene and coconut oil as clearing agents. The xylene-treated specimens and coconut oil-treated specimens were checked for gross and histological features, and a comparison was done between the two groups. Results: Significant shrinkage was noted in xylene-treated specimens compared to that in coconut oil-treated specimens. No difference was found in either of the sections when checked for staining quality, overall morphological features and cellular details. Conclusion: It may be substituted for xylene without loss of information.

Malignant melanoma of gingiva: Case report and review of the literature.

Mucosal malignant melanoma arising from the head and neck region is a rare entity, and it is more aggressive than cutaneous melanoma. Furthermore, the complexity of the oral cavity makes surgical excision more difficult. Oral malignant melanoma is a rare tumour of melanocytic origin, accounting for 20-30% of malignant melanomas at the mucosal surface and 16% intra-orally. Hard palate and maxillary gingiva are the most common involved sites. The age of reported patients ranges from 20 years to 80 years. Hence, we do hereby present a case of malignant melanoma of mandibular gingiva with review of the literature in a 42-year-old female patient.