[Histopathological differentiation between well differentiated oral squamous cell carcinoma and oral verrucous carcinoma with special staining of basement membrane]

Microscopic differentiation between well differentiated squamous cell carcinoma and verrucous carcinoma is very difficult. As these lesions have different clinical course and treatment a reliable method to help distinguish between them is necessary. The basement membrane in oral verrucous carcinoma is generally intact whereas in oral squamous cell carcinoma is mostly discontinuous. This structure can be studied by different methods. The aim of this study was to differentiate these lesions with special staining of basement membrane. In this tests evaluation study, a total of 26 cases consisting of 15 oral squamous cell carcinomas and 11 oral verrucous carcinomas were retrieved from Cancer Institute of Imam Khomeini hospital archive of pathology and their paraffin blocks were cut and stained with Periodic Acid Schiff method. Slides were studied with light microscope to evaluate the continuity of basement membrane. Sensitivity and specificity of this method were calculated. The sensitivity of this method for differentiating oral squamous cell carcinoma from oral verrucous carcinoma was 100% whereas the specificity was 90.9%. Positive predictive value was 93.75% and negative predictive value 100%. Based on the results of this study, the sensitivity of this test for diagnosis of oral squamous cell carcinoma was high [100%]. Further studies are needed to evaluate the use this method for distinguishing oral verrucous carcinoma from oral squamous cell carcinoma

[Differential diagnosis of myoxid lesions in head and neck area with special staining of mucin]

Background and aim: myoxid histological pattern is of nonspecific features that is seen in most of benign and malignant lesions occupying a great mass of them. Thus, histopathologic diagnosis depends on a careful and precise investigation. The aim of this study was to differentiate between mucins in myoxid tissues through histochemical staining

Materials and Methods: archives of three important educational pathology departments [Faculty of Dentistry of Tehran University, cancer institute of Imam Khomeini hospital and Amir Alam hospital] were investigated and information on head and neck tumors with myoxid histopathologic pattern were worked out, then slides and paraffin embeded blocks were studied. Tissue slides of 5,um thickness were stained with PAS/Alcian blue technique and studied under light microscope. The notable standard was the predominant stain of mucin in histological field

Results: the study of 41 histologic slides containing: malignant fibrous histocytoma [MFH][n=4], Rhabdomyosanvma [n=6], Chondrosar coma [n=6], Schwannoma [n=7], Neurofibroma [n=8], Pleomorphic adenoma [n=4] and Odontogenic myxoma [n=6], revealed that neurologic derived lesions and Rhabdomyo sarcoma and MFH had notable red field [neutral mucin nature] where as chondrosarcoma, pleomorphic adenoma and odontogenic myxoma had notable blue field [acidic mucin nature]

Conclusion: despite limited cases, the results showed that different nature of mucins in different lesions can be considered as a good criteria for differential diagnosis, however, more detailed studies are recommended