Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma.

Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma is a distinct subgroup of non-Hodgkin's lymphoma. Chronic antigen stimulation, triggered by autoimmune process or persistent infection may precede the development of BALT lymphoma. The lymphoma cells originate from the marginal zone and by invading the bronchial epithelial tissue, give rise to the lymphoepithelial lesion. BALT lymphoma shares the morphologic, immunophenotypic, and cytogenetic characteristics of other mucosa associated lymphoid tissue lymphomas. A majority of the patients are asymptomatic and pulmonary lesions are incidentally discovered on a routine chest radiograph. However, the clinical and radiographic features of BALT lymphoma are nonspecific. The disease is often localized at the time of diagnosis and responds favorably to local treatment, but the optimal management is not clearly defined. Overall, BALT lymphoma has a favorable prognosis and is associated with long-term survival.