Aims: The study cytomorphologic features that distinguish cystic papillary thyroid carcinoma  from other cystic thyroid lesions.

Materials and Methods: This study was carried out in the department of pathology in a tertiary care health centre in north India over the period of one year.

Results:  Total 70  lesions showed cystic degeneration were included in the study. Out of 70 cases 18 were malignant and 52 were benign. All cystic neoplasm showed histiocytes, multinucleated giant cells and calcification/ crystals. All cystic papillary carcinoma showed  papillae, intranuclear cytoplasmic inclusions, nuclear grooves and  histiocytoid cells .In addition  psammoma bodies ( 6 cases) , mesothelial like cells with windows  ( 5 cases) and clusters with cartwheel pattern ( 3 cases)  and isolated plasmacytoid cells ( 7 cases) were also observed.

Conclusion:  Cystic change is common finding in both benign and malignant lesions of thyroid. However by keen observation and collaborating all cytological, clinical and radiological features   we can reach to the diagnosis.