Background: Fine needle aspiration cytology (FNAC) is considered an essential step in the thyroid workup. Altered follicular cells are known as oncocytic cells, oxyphilic cells, Hurthle cells or Askanazy cells. Oncocytic cells may be encountered in a number of thyroid conditions.

Aims: To study the cytomorphological features of oncocytic lesions in thyroid aspirates. Settings and Design: Hospital based and prospective study.

Methods and Material: The present study was a prospective study (June 2016 to  November 2017) carried out in the Department of Pathology. Patients recommended for FNAC by the clinicians were incorporated into the study. Aspirated material was stained with Giemsa stain and Papanicolaou stain. Stained smears were subjected to microscopic examination. Statistical Analysis: Chi square test was used.

Results: A total of 240 cases were included in present study. Oncocytic cells were seen in 154 cases. Oncocytic cells were seen in both neoplastic as well as non-neoplastic lesions of thyroid. In oncocytic cell positive cases, majority of cases were of Hashimoto’s thyroiditis. Neoplastic lesions had cells in sheets without intra epithelial lymphocytes with no to scanty colloid.

Conclusions: Hashimoto’s thyroiditis is most common thyroid lesion in this area. Oncocytic cells when present in follicles, large clusters or multilayered sheets & scanty colloid favor the diagnosis of neoplastic lesions. Abundant colloid favors the non neoplastic lesions.

Keywords: Cytology; FNAC; Hurthle Cells; Hashimoto’s Thyroiditis; Oxyphilic Cells.