Imprint cytologic and immunocytochemical findings of sclerosing pneumocytoma.

To the best of our knowledge, there is no description on immunocytochemical study of sclerosing pneumocytoma (SP) using a cell transfer method. In this article, we report imprint cytological and immunocytochemical findings of SP. Three cases of SP possessing both imprint cytological and histological materials were examined. All tumors showed well-defined margin grossly. On microscopic examination, the tumor consisted of surface and stromal round cells. Cytologically, surface and stromal round cells showed fragments or clusters of papillary configuration with low N/C ratio and cell clusters of small to medium-sized cells with high N/C ration. Immunocytochemically, surface cells showed the positive reaction for surfactant apoprotein A (SPA), but stromal round cell exhibited the negative reaction for SPA. Cytologists and pathologists should steadily recognize cytological findings of surface and stromal round cells of SP. Immunocytochemistry of SPA may be useful in the discrimination of both cells. Diagn. Cytopathol. 2017;45:274-278.