Accelerated staining technique using kitchen microwave oven.

Introduction: Histopathological diagnosis of specimens is greatly dependent on good sample preparation and staining. Both of these processes is governed by diffusion of fl uids and dyes in and out of the tissue, which is the key to staining. Diffusion of fl uids can be accelerated by the application of heat that reduces the time of staining from hours to the minute. We modifi ed an inexpensive model of kitchen microwave oven for staining. This study is an attempt to compare the reliability of this modifi ed technique against the tested technique of routine staining so as to establish the kitchen microwave oven as a valuable diagnostic tool. Materials and Methods: Sixty different tissue blocks were used to prepare 20 pairs of slides for 4 different stains namely hematoxylin and eosin, Van Gieson’s, 0.1% toluidine blue and periodic acid-Schiff. From each tissue block, two bits of tissues were mounted on two different slides. One slide was stained routinely, and the other stained inside a microwave. A pathologist evaluated the stained slides and the results so obtained were analyzed statistically. Results: Microwave staining considerably cut down the staining time from hours to seconds. Microwave staining showed no loss of cellular and nuclear details, uniform-staining characteristics and was of excellent quality. Interpretation and Conclusion: The cellular details, nuclear details and staining characteristics of microwave stained tissues were better than or equal to the routine stained tissue. The overall quality of microwave-stained sections was found to be better than the routine stained tissue in majority of cases.

Comparative study of various grading systems in oral squamous cell carcinoma and their value in predicting lymph node metastasis.

Background: Regional lymph node (LN) metastasis is the single most prognostic factor for oral squamous cell carcinoma (OSCC). An analysis of the prognostic factors is important for predicting prognosis and reducing the mortality in these patients. Objectives: (1) To compare the value of various grading systems in predicting LN metastasis. (2) To evaluate histopathological parameters, which could help in predicting LN metastasis. Materials and Methods: A total of 20 excisional biopsies of OSCCs, were graded according to the four grading systems that is, Broder’s, Jakobsson's, Anneroth and Hansen’s, and Brynes. We also evaluated various histopathological parameters, which could help in predicting LN metastasis. Results: Grading at the invasive front was most prognostic of LN metastasis. Tumors with total malignancy score ≥8 showed higher incidence of metastases. Conclusion: The histopathological parameters that could help in predicting lymph node metastases (LNM) are keratinization, nuclear pleomorphism (NP), and the pattern of invasion (POI) when assessed at the invasive front. When the whole tumor was considered, histopathological parameters like NP and POI were significant in predicting LNM.