Various studies suggest that a causal relationship might exist between asbestos exposure and the development of lymphoproliferative disorders.1,2 We report the appearance of a non-Hodgkin lymphoma in a patient with a history and signs of heavy exposure to asbestos.

An 86-year-old man was admitted to a general hospital in January 2011 for dyspnea, fatigue, and weight loss. Chest X-ray showed left pleural effusion. Past disease history included gastric resection for peptic ulcer in 1950, aortic valve replacement in 2008, and colon polypectomy in 2010. The patient had worked for about 14 years as a shipwright with various firms in the shipbuilding industry in Trieste, and as a mechanic for 4 years in an oil refinery. Chest computed tomography showed left pleural effusion, and bilateral thickening of the pleura with calcifications. Thoracoscopy was not performed in view of the patient's age. In June 2012, chest radiography showed an opacity at the apex of the right lung. By July 2012, the thoracic opacity had spread to the right upper mediastinum. The patient died in July 2012 with a diagnosis of acute respiratory failure, due to probable neoplasia of the pleura. Right pleural effusion was observed on autopsy. Right parietal pleura showed large pleural plaques and soft, whitish neoplastic nodules. Similar nodules were visible on the surface of the right lung without infiltration of the parenchyma, and in the pericardium. The left lung showed atelectasis of the lower lobe and marked edema of the upper lobe. Left pleural effusion was no longer visible. Mediastinal lymph nodes appeared enlarged with masses similar to those seen in the right lung. Histological examination found that the nodules in the right pleura, lung and lymph nodes were composed of sheets of small and large lymphoid cells. Immunohistochemistry (CD20, CD3, CD56, CK Ae1-Ae3, synaptophysin) was consistent with a diagnosis of B cell non-Hodgkin lymphoma. The lungs showed asbestosis: high burdens of asbestos bodies (57000 bodies per gram of dried tissue) were isolated from the lung after chemical digestion of the pulmonary tissue (Smith and Naylor method3).

The clinical diagnosis of this patient with a history of severe asbestos exposure and pleural pathology remained undefined. The case is similar in some ways to that described by Parisio et al.4 Numerous studies have explored the possible relationship between asbestos exposure and non-Hodgkin lymphoma or hematopoietic cancer in general.1,2,4 The association between non-Hodgkin lymphoma and asbestos-related mesothelioma, in particular, does not seems to be exceptional.1 In a recent study of a large mesothelioma series, including more than 3600 cases,2 there were 45 cases of hematopoietic malignancies. While the role of radiation in the genesis of mesothelioma in patients who had received previous radiotherapy is plausible, the majority of non-Hodgkin lymphoma patients were radiotherapy-naïve.

Various elements suggest a relationship between asbestos and non-Hodgkin lymphoma. Firstly, the relatively high prevalence of the association between mesothelioma and lymphoma (both rare in the general population) is difficult to attribute to chance. Secondly, extranodal lymphoma (a variety particularly observed among immunocompromised individuals) has repeatedly been reported.1 Thirdly, the recognized effects of asbestos on immune mechanisms5 confers biological plausibility to the notion of a relationship between asbestos and lymphoma.