FOLLICULAR ADENOMA OF THE THYROID: RETROSPECTIVE REVIEW OF THE CYTOMORPHOLOGIC CHARACTERISTICS IN 104 CASES

SUMMARY · Thyroid fine-needle aspiration biopsy samples from 104 patients with subsequent histopathologic diagnosis of follicular adenoma of the thyroid formed the basis of this review. Cytomorphologic features for detailed cytologic assessment included cellular patterns, cellularity, colloid content, nuclear enlargement, nuclear pleomorphism, nuclear grooves, nucleoli, marginal vacuoles, macrophages, and Hürthle cells. Of the four cellular patterns assessed, acinar formation was observed in most cases (87%), while the remaining cellular patterns were present in the follow-ing order: honeycomb pattern in 65%, single-cell pattern in 57%, and syncytial pattern in 45 % of cases. Most of the cases were hypercellular (70%), while colloid content was absent or scanty in 65% of cases. Nuclear enlargement was present in 84%, and nuclear pleomorphism in 75 % of cases. Nuclear grooves were detected in 12%, while nucleoli were not identifiable in 66 % of cases. Marginal vacu-oles were found in 14%, macrophages in 30%, and Hürthle cells in 15 % of cases