[1647] Radiation-Induced Malignant Mesothelioma Following Treatment for Hodgkin Lymphoma

MA Vasef, K Sheibani, D Lopez, S Sheibani. University of New Mexico, Albuquerque, NM; Western Medical Center, Santa Ana, CA; University of Southern California, Los Angeles, CA

Background: Recent epidemiologic studies have demonstrated an increased risk of malignant mesothelioma (MM) in patients who have received radiation therapy for testicular tumors and hematolymphoid malignancies. However, there have been no studies to determine whether there are any morphologic or immunohistochemical features that distinguish radiation-induced MM from asbestos-related MM. The purpose of our study was to compare morphologic and immunohistochemical features of radiation-induced MM with those of asbestos-related MM.
Design: We studied materials from ten patients (six men and four women with an age ranging from 35 to 74) who developed MM after radiation treatment for Hodgkin lymphoma (HL) at the site of radiation therapy. The diagnosis of MM had been immunohistochemically confirmed in all ten cases. The average duration between the treatment of HL and the development of MM was 29 years. Five patients had either a history of exposure to asbestos (occupational or non-occupational) or pleural fibrosis. These five patients were excluded from this study. The morphologic and immunohistochemical features in remaining five cases were compared with 100 cases of immunohistochemically confirmed MM.
Results: We found no morphologic or immunohistochemical features that could distinguish radiation-induced MM from those of asbestos-related MM.
Conclusions: Our study confirms an etiologic link between therapeutic radiation and the development of MM. However, we found no distinct morphologic or immunohistochemical features that can distinguish radiation-induced MM from asbestos-induced MM. Given the known DNA alterations induced by radiation, molecular genetic studies to screen for genetic alterations may prove helpful to determine whether there are any distinct genetic abnormalities that can separate radiation-induced MM from asbestos-related MM.
Category: Pulmonary

Tuesday, March 10, 2009 11:30 AM

Platform Session: Section F 2, Tuesday Morning