Lymphoma of pulmonary mucosa-associated lymphoid tissue: CT scan findings and pathological correlations

The aim of this study was to describe the lesions of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma observed by means of computed tomography (CT) and to determine the value of CT in the management of this disease. Sixty six CT scans were performed in 13 consecutive cases of histologically proven pulmonary MALT lymphoma at the time of diagnosis (n=13) or periodically (n=53). They were reviewed separately with chest radiographs by consensus between two observers. Pulmonary abnormalities were described and compared to histopathological findings on surgical specimens from seven patients. At the time of diagnosis, elementary lesions observed by means of CT consisted of nodular areas of attenuation (12 of 13), linear areas of attenuation (eight of 13) and consolidations (six of 13). All these lesions were centred on airways that appeared dilated in seven cases and were more often bilateral and multiple on CT than on the chest radiographs. CT abnormalities correlated with gross pathological appearance and were related to a lymphomatous infiltration with a peribronchovascular distribution. Pathological examination also confirmed the presence of dilated airways within lymphomatous lesions and showed that the bronchial wall was respected. During follow-up, in patients on chemotherapy, response, relapse or progression were easily identified by means of plain radiography. In the initial evaluation, computed tomography contributed to the choice of therapeutic strategy, avoiding unnecessary surgical resection in one-third of patients. By contrast, it is unclear whether computed tomography is useful for post-treatment follow-up of mucosa-associated lymphoid tissue.