Pulmonary Sclerosing Hemangioma Exhibiting a High KI-67 Proliferation Index

Pulmonary sclerosing hemangioma (PSH) is a rare pulmonary neoplasm. This tumour was originally thought to be a variant lesion of hemangioma. Today, however, it has been elucidated to be a tumour of epithelial origin derived from the primitive respiratory epithelium. Previous studies have reported a low Ki- 67 proliferation index in cases of pulmonary sclerosing hemangioma (1.4-2.2%). Moreover, the biological nature of this neoplasm, which rarely tends to metastasise to the lymph nodes, has yet to be thoroughly elucidated. A female patient in whom PSH exhibiting a high Ki-67 proliferation index was detected in the lung during follow-up for lymphoma is reported in the present study. While the Ki 67 proliferation index was 3-4% in some areas, it increased up to 15-20% in other areas. No recurrence or metastases were evident at postoperative follow-up.