Thyroid oncocytic neoplasms

Oncocytic tumors (OT) are rare, representing 3 to 10% of epithelial tumors of the thyroid. It is important to individualize these TO given the relatively high frequency of carcinomas in this group: 30% against 15% for micro-vesicular lesions of classical cytology and the aggressiveness of malignant OT due to their low iodine uptake.

The aim of our study was to describe the anatomo-clinical aspects of oncocytic tumors of the thyroid.

Our study was retrospective, realized on 99 cases of oncocyte thyroid tumors collected at the Anatomy and Pathology Cytology laboratory of Tunis Charles Nicolle Hospital during a 10-year period (2004-2014).

Our series included: 76 oncocyte adenomas, 13 oncocytic papillary carcinomas, 7 oncocytic carcinomas and 3 tumors of uncertain malignant potential (3%). The correlation of the anatomo-clinical data with the diagnostic categories showed a statistically significant difference concerning the macrovesicular architecture. We found no difference between benign and malignant TO, in relation to age, echogenicity, tumor size, macroscopic appearance, capsule thickness, percentage of oncocyte cells, and the presence of associated lymphocyte thyroiditis.

In view of the literature data and the findings of our study, it seems that there are no predictive factors for the malignancy of oncocytic tumors at the pre- and peroperative stage, with the exception of papillary-type nuclear atypia for Oncocytic papillary carcinoma.