The key to the interpretation of thyroid fine needle aspiration is largely
dependent on the recognition of various morphologic patterns of epithelial
cells, usually follicular cells, and background elements, such as colloid,
These morphologic patterns consist of 3 parts: 1) The arrangement of cells
with respect to one another, 2) The cytologic features of individual cells,
and 3) The presence of background elements, The cellular arrangements gene
rally encountered in fine needle aspiration of the thyroid include the foll
icular patterns (macro-/normo-follicular and micro-follicular), the papilla
ry pattern, the syncytial pattern, the dispersed cell pattern, and the cyst
ic pattern. This article approaches some of the differential diagnostic cha
llenges encountered while interpreting thyroid aspiration cytology by focus
ing first on the overall cellular arrangement to generate a differential di
agnosis and then narrowing that differential by assessing cellular features
of individual cells and the presence of background elements, Copyright (C)
2001 by W.B. Saunders Company.