IntroductionPulmonary B-cell non-Hodgkin's lymphomas, although rare, are now well recognised as primary lung neoplasms. They have previously been classified according to nodal classification systems, [1,2,3,4] but are currently thought to be primary extranodal lymphomas, mainly of low grade, which arise from bronchial mucosa-associated lymphoid tissue (MALT) [5,6,7,8]. These are analogous to extranodal MALT lymphomas, which were first described in the stomach [9] and are now known to arise at numerous other mucosal sites [10,11,12,13]. MALT lymphomas are now classified in the revised European American system as extranodal, marginal zone, B-cell lymphomas [14]. Most lung lesions that were previously termed ªpseudolymphomasº [15] are now also thought to represent pulmonary MALT lymphomas. The radiographic features of pulmonary involvement by other types of lymphoma have been previously described [16,17,18,19], although the radiological appearances of pulmonary MALT lymphomas are less well documented [20,21,22,23,24,25] with no large series reporting the findings on CT.The purpose of this article is to describe the radiological appearances of pulmonary MALT lymphomas in a series of 24 histologically diagnosed cases.
Materials and methods
PatientsReview of pathological records at the Royal Brompton Hospital from 1985 to 1998 identified 40 patients with pulmonary MALT lymphoma. Thoracic imaging was available in 25 of these patients, one of whom had a history of a previous orbital high-grade non-Hodgkin's lymphoma and was excluded from this study. The remaining 24 patients presented with pulmonary lesions and comprised 18 men and 6 women, aged 27±78 years (mean age 56 years). The case notes and radiological investigations of these 24 patients were retrospectively reviewed. Case notes were examined for a history of autoimmune disorder, co-existing chest disease, previous lymphoma, evidence of extra-thoracic lymphoma, acquired immune deficiency syndrome (AIDS) and the method employed in obtaining a diagnostic specimen of lung tissue for each patient.Abstract. The aim of this study was to describe the imaging features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma. The chest radiographs (n = 18) and CT scans (n = 17) of 24 patients (18 men and 6 women) aged 27±78 years (mean = 56 years), with a known diagnosis of pulmonary MALT lymphoma, were retrospectively reviewed by two radiologists and the imaging findings are described. Six of the 24 patients had a history of an autoimmune disorder and 1 patient had acquired immune deficiency syndrome. Multiple pulmonary lesions were identified in 19 of 24 patients (79 %) and solitary lesions in 4 of 24 patients (17 %). Diffuse pulmonary infiltration was present in 1 patient. Lesions included masses or mass-like areas of consolidation (n = 21) and pulmonary nodules (n = 18). Associated findings were air bronchograms, airway dilatation, a positive angiogram sign and a halo of groundglass shadowing at lesion margins. Peribronchovascular thickening was also observed, as...