Pulmonary sclerosing hemangioma associated with familial adenomatous polyposis.

A 45-year-old woman presented with asymptomatic solid tumor in the lower right lobe of the lung. Histologically, the tumor comprised a monolayer of surface cells and round stromal cells displaying sclerotic areas. Immunohistochemical studies suggested a diagnosis of sclerosing hemangioma. Interestingly, morular lesions were also observed. Analyses of the gastrointestinal (GI) tract showed mild familial adenomatous polyposis (FAP) and numerous fundal gland polyps, indicating attenuated FAP (AFAP). All components of the sclerosing hemangioma displayed aberrant nuclear and cytoplasmic expression of β-catenin. However, such findings were much weaker in adenomas of the GI tract and were barely observed in fundal gland polyps. These results strongly suggest an association between sclerosing hemangioma and the AFAP. To the best of our knowledge, this is only the second report of lung tumor associated with FAP and is the first describing an association with sclerosing hemangioma. A new category of FAP-associated lung tumors may be indicated.