Clinicopathologic Characteristics of Malignant Mesotheliomas Arising in Patients With a History of Radiation for Hodgkin and Non-Hodgkin Lymphoma

Purpose Studies have reported an association between pleural diffuse malignant mesothelioma (PDMM) and chest radiation for lymphoma. The clinicopathologic characteristics of malignant mesotheliomas arising in these patients have not been established. Patients and Methods We studied 1,618 consecutive patients diagnosed with pleural PDMM from July 1993 to February 2008 and identified patients with a history of radiation for Hodgkin and non-Hodgkin lymphoma. We evaluated the histology in the surgical resection specimens and compared clinicopathologic features with overall survival. Results We identified 22 patients who developed PDMM after chest radiation as part of their treatment for lymphoma (mean latency time, 21.4 years; 95% CI, 17.0 to 25.8 years). Asbestos bodies in lymphoma-associated PDMM were lower than in asbestos-associated PDMM (median count, 15 v 325 bodies, respectively; P < .001) and similar to an unexposed control group (median count, 15 v 10 bodies, respectively; P = .6). Seventeen lymphoma-associated PDMMs (77%) were epithelioid and five (23%) were biphasic. Seven PDMMs (32%) had unusual histologies (pleomorphic, myxoid, clear cell, and signet ring cell). Patients with lymphoma-associated PDMM were younger than patients with asbestos-associated PDMM (median age, 45 v 64 years, respectively; P < .001) and had a significantly longer overall survival time (median, 32.5 v 12.7 months, respectively; P = .018). In multivariate analysis, independent favorable predictors for overall survival were history of prior radiation (P = .022), female sex (P < .001), age 65 years (P = .005), cytoreductive surgery (P < .001), and epithelioid histology (P < .001). Conclusion Patients with lymphoma-associated PDMM are likely to have unusual histologic features, are significantly younger, and seem to have a longer overall survival compared with patients with asbestos-associated PDMM.