Thyroid Neoplasms Constitute The Most Common Of All Endocrine Neoplasms And More Than 95 % Arise From Follicular Epithelial Cells. They Encompass A Wide Variety Of Benign And Malignant Tumours. The Most Common Malignant Tumour Is Papillary Carcinoma With A Frequency Of 70 To 85 % With Preponderance Among Young Females.
Historically, The Identification Of Papillary Carcinoma Relied On The Presence Of Papillary Architecture. The Current Accepted Diagnosis Is Based On The Nuclear Features That Include Optical Clearing, Overlapping, Nuclear Grooves And Pseudoinclusions. However, Identification Of These Features Remains, At Times Controversial And The Distinction Of Papillary Carcinoma From Its Histological Mimickers Such As Follicular Adenoma And Follicular Carcinoma May Sometimes Be Difficult.1
Despite The Propensity For Lymphatic Dissemination To The Cervical Lymph Nodes, The Majority Of Patients With These Tumours, If Appropriately Treated, Have An Excellent Long Term Prognosis Compared To Nonpapillary Tumours. Hence It Becomes Mandatory To Diagnose Papillary Carcinoma Correctly For Therapeutic Purposes And For Assessing The Prognosis. Immunohistochemistry Helps In The Circumstances Where Cytological Features Do Not Suffice For Differential Diagnosis.2
The Present Study Aims At Histologically Classifying All Thyroid Neoplasms And To Study Its Histomorphological Characteristics And To Evaluate The Expression Of Immunohistochemical Markers Such As Cytokeratin 19 And Thyroglobulin In Cases Of Papillary Thyroid Carcinoma And Its Histological Mimickers
