Architectural patterns in cytology: correlation with histology

Cellular arrangements are highly relevant in the evaluation of histologic sections, but cytologic specimens are not thought to accurately reflect the same patterns. Only occasionally do cytologic descriptions comprise, apart from cytoplasmic and nuclear features, architectural patterns. Architectural arrangement of cells in cytologic specimens, however, may mirror the corresponding arrangement of cells in histologic specimens provided the cytologic preparations are collected and prepared appropriately. Recognition and understanding of the different types of cell arrangements that may be seen in cytologic specimens can provide important information for obtaining a definitive diagnosis, particularly for neoplastic lesions. The goal of this review is to describe the most common architectural patterns observed in cytologic specimens and to draw correlations with similar histologic arrangements.