Allergic angiitis and granulomatosis (Churg-Strauss syndrome): report of a case with massive thymic involvement in a nonasthmatic patient.

A 14-year-old nonasthmatic boy who presented with multiple skin lesions and a mediastinal tumor was found to have allergic angiitis and granulomatosis (AAG) (Churg-Strauss syndrome), with prominent involvement of the thymus. The occurrence of AAG in the thymus merits recognition because of possible confusion with a variety of other lesions characterized by proliferation of histiocytes and tissue eosinophilia that affect this organ. In addition, this case illustrates that the absence of asthma should not be used as a definitive criterion for exclusion of the diagnosis of AAG.