Thyroid Angiosarcoma : An unusual and challenging case report at B.P. Koirala Institute of Health Sciences.

Angiosarcoma is an uncommon malignant vascular tumor of endothelial origin and commonly described in soft tissue. Thyroid is an uncommon site for angiosarcoma and is a very aggressive tumor commonly occurring in elderly female, characterized by its prevalence in Alpine regions of central Europe. The main aim of this case report is to provide an insight on thyroid angiosarcoma (TAS) occurring in nonAlpine region, to know the major diagnostic features of thyroid angiosarcoma and distinguish it from anaplastic thyroid carcinoma with angiomatoid features. Due to its overlapping microscopic features diagnosis of primary thyroid angiosarcoma (TAS) was challenging. However, the combination of thorough microscopic findings and immunohistochemical studies (CD 31, Vimentin, Thyroglobulin and Thyroid Transcription Factor-1) are vitally important in differentiating these two tumors to achieve at a final diagnosis. This significantly helps to decide the best treatment option and predict the behaviour.