The histopathology analysis of the diffuse sclerosing variant of the papillary carcinoma of the thyroid: a distinctive and rare form.

Diffuse sclerosing variant (DSV) is a rare variant of papillary thyroid carcinoma (PTC) and its features have not yet been fully characterized. The aim of this case report is to analyze the immunohistochemistry profile of this disease and to highlight this rare entity. We analyzed the histology and immunohistochemistry of a female patient admitted in the Surgery Department of the "Sf. Ioan" Emergency Hospital, Bucharest, in April 2008. We especially used a wide panel of antibodies (Thyroglobulin mono, Thyroglobulin poly, Ki-67, TTF 1, Cytokeratin 19, Cytokeratin 34betaE12, and p63) in order to point out the follicular origin of the cells and to investigate the extensive squamous metaplasia lesions. The immunohistochemistry (IHC) was performed on 3 mum thick sections from 10% formalin-fixed paraffin-embedded tissues, according to the indirect tristadial Avidin-Biotin-Complex method. Our case report reveals that the DSV of PTC has distinctive pathologic features and its diagnosis importance is suggested by the high incidence of recurrence after operation.