Imprint cytologic features of pulmonary sclerosing hemangioma - Comparison with well-differentiated papillary adenocarcinoma

BACKGROUND. Sclerosing hemangiomas (SH) of the lung are uncommon tumors and are thought to be benign. However, histogenesis of these tumors has not yet been characterized adequately. Moreover, there are few reports dealing with their cytologic features, and it is generally considered difficult to make accurate diagnoses of sclerosing hemangiomas that have a predominantly papillary pattern. METHODS. Cytologic features were analyzed for 15 sclerosing hemangiomas, and cytologic features of sclerosing hemangioma were compared with features of 22 cases of well-differentiated papillary adenocarcinoma classified as pathologic Stage 1A. RESULTS. Blood and round cells were observed more frequently in SH than in adenocarcinomas (P < 0.05), whereas necrosis was seen more frequently in adenocarcinomas than in SH (P < 0.05). The presence of nucleoli, nuclear indentations, irregularities of nuclear margins, nuclear polymorphisms, and high nuclear-cytoplasmic (NC) ratios of tumor cells were observed less frequently in SH. Polynuclear (having three or more nuclei) tumor cells were observed only in adenocarcinoma cases. In morphometric studies, the nuclear areas, cytoplasmic areas, NC ratios, long axes of nuclei, short axes of nuclei, and nuclear rotundity ratios were significantly higher in adenocarcinoma cells than in SH cells (P < 0.05). CONCLUSIONS. The presence of polymorphous cells and turner cells with bland nuclei are characteristic cytologic findings associated with sclerosing hemangioma. It is possible to make accurate diagnoses for SH cases preoperatively by careful cytologic characterization.