Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type of the lung


This is a type of extranodal marginal zone lymphoma. The neoplastic lymphoid cells characteristically infiltrate the bronchiolar epithelium to form lymphoepithelial lesions.


Pulmonary mucosa-associated lymphoid tissue (MALT) is acquired secondary to antigenic stimuli or autoimmune disease, with subsequent progression to lymphoma. Unlike other forms of marginal zone lymphoma, an aetiological infective agent has not yet been identified. Even in cases associated with H. pylori gastritis, PCR does not demonstrate Helicobacter in the lungs3.


Marginal zone lymphoma accounts for less than 0.5% of all lung neoplasms and of all lymphomas, but constitutes 70-90% of all lung lymphomas. It is not uncommon for patients to have extranodal MALT lymphoma at other sites.

Clinical features

Most patients are older adults. Marginal zone lymphoma in young adults is usually associated with immunosuppression. Autoimmune disease and monoclonal gammopathies are common8,11.


Lesions are usually peripheral. There may be a solitary nodule9, multiple nodules9 or diffuse bilateral disease: unilateral disease is more common than bilateral8. Associated findings are air bronchograms, airway dilatation, a positive angiogram sign and a halo of ground-glass shadowing at lesion margins7. Peribronchovascular thickening may also observed, as may hilar or mediastinal lymph node enlargement and pleural effusions or thickening7.

Macroscopic appearances

Resembles lymphoma of lymph node. Rarely, there may be cystic degeneration.


The histopathology resembles that of extranodal marginal zone lymphoma at other sites. In most cases, reactive follicles are smaller than those seen in gastric MALT lymphoma. Although the formation of lymphoepithelial lesions is characteristic2, they may also be seen in non-neoplastic pulmonary lymphoid infiltrates3. The lymphoid infiltrate often tracks along bronchovascular bundles3,10 and interlobular septa10, leaving airways intact, and may involve the pleura3. Invasion of bronchial cartilage favours malignancy6. Centrally, the lung parenchyma is destroyed and there may be sclerosis10: in some cases, the hyalinosis may be a dominant feature13. There may be epithelioid histiocytes, giant cells or granulomata13. Giant lamellar bodies may occur1. Amyloid deposition may be seen. A case with massive crystal storing histiocytosis has been reported14.

Tumours with a predominance of large cells should be designated as diffuse large B-cell lymphoma: often there is evidence of a pre-existing low grade MALT lymphoma3,8.


As for extranodal marginal zone lymphoma at other sites. Light chain restriction is diagnostically very useful, but may be masked by polyclonal reactive follicles and plasma cells2. The neoplastic cells are usually positive for bcl-2 and bcl-1012 and show an aberrant phenotype CD20+/CD 43+3. CD21, CD23 and CD35 highlight the meshwork of expanded follicles overrun by neoplastic cells10. Anticytokeratins high-light lymphoepithelial lesions10.

Differential diagnosis

Clinically: sarcoid, organising pneumonia, infections, bronchoalveolar carcinoma, amyloidosis.


See other low grade non-Hodgkin's lymphomas: immunophenotypes


If resectable, surgery. Otherwise as for lymphoma elsewhere.


MALToma of lung tends to remain localised2, conferring a good prognosis and potential for cure. Spread may occur to lymph nodes, stomach or salivary glands9. Five year survival is 84-94%, 72% at ten years8. A few cases progress to diffuse large B-cell lymphoma.


Tumours of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumours. IARC Press 2004.

1 Perry L, Florio R, Dewar A, et al. Giant lamellar bodies as a feature of pulmonary low-grade MALT lymphomas. Histopathology 2000; 36:240-4.

2 Addis BJ, Hyjek E,Isaacson PG Primary pulmonary lymphoma: a re-appraisal of its histogenesis and its relationship to pseudolymphoma and lymphoid interstitial pneumonia. Histopathology 1988; 13:1-17

3 Begueret H, Vergier B, Parrens M, et al. Primary Lung Small B-Cell Lymphoma versus Lymphoid Hyperplasia: Evaluation of Diagnostic Criteria in 26 Cases. Am J Surg Pathol 2002; 26:76-81.

4 Abbondanzo SL, Rush W, Bijwaard KE, et al. Nodular lymphoid hyperplasia of the lung: a clinicopathologic study of 14 cases. Am J Surg Pathol 2000; 24:587-97

5 Dacic S, Colby TV,Yousem SA Nodular amyloidoma and primary pulmonary lymphoma with amyloid production: a differential diagnostic problem. Mod Pathol 2000; 13:934-40

6 Koss MN, Hochholzer L, Nichols PW, et al. Primary non-Hodgkin's lymphoma and pseudolymphoma of lung: a study of 161 patients. Hum Pathol 1983; 14:1024-38

7 King LJ, Padley SP, Wotherspoon AC, et al. Pulmonary MALT lymphoma: imaging findings in 24 cases. Eur Radiol 2000; 10:1932-8

8 Kurtin PJ, Myers JL, Adlakha H, et al. Pathologic and clinical features of primary pulmonary extranodal marginal zone B-cell lymphoma of MALT type. Am J Surg Pathol 2001; 25:997-1008

9 Li G, Hansmann ML, Zwingers T, et al. Primary lymphomas of the lung: morphological, immunohistochemical and clinical features. Histopathology 1990; 16:519-31

10 Nicholson AG, Wotherspoon AC, Diss TC, et al. Pulmonary B-cell non-Hodgkin's lymphomas. The value of immunohistochemistry and gene analysis in diagnosis. Histopathology 1995; 26:395-403

11 Nicholson AG, Wotherspoon AC, Jones AL, et al. Pulmonary B-cell non-Hodgkin's lymphoma associated with autoimmune disorders: a clinicopathological review of six cases. Eur Respir J 1996; 9:2022-5

12 Ohshima K, Muta H, Kawasaki C, et al. Bcl10 expression, rearrangement and mutation in MALT lymphoma: correlation with expression of nuclear factor-kappaB. Int J Oncol 2001; 19:283-9

13 Kojima M, Nakamura S, Ban S, et al. Primary pulmonary low-grade marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type with prominent hyalinosis. A case report. Pathol Res Pract 2002; 198:685-8

14 Fairweather PM, Williamson R,Tsikleas G. Pulmonary extranodal marginal zone lymphoma with massive crystal storing histiocytosis. Am J Surg Pathol 2006; 30:262-7

This page last revised 31.1.2006.

©SMUHT/PW Bishop