Objective: To investigate the features of gene rearrangement of immunoglobulin heavy chain (IgH) and immunophenotypes of pulmonary mucosa-associated lymphoid tissue type lymphoma (MALTLoma).
Methods: The clinical and pathological data of 12 cases with pulmonary MALTLoma and follow-up information were retrospectively reviewed, and the paraffin-embedded samples were examined with immunohistochemistry staining (12 cases) and semi-nested polymerase chain reaction (PCR) for IgH and T-cell receptor gamma (TCRgamma) gene rearrangement (7 cases).
Results: The patients included 9 cases confirmed by open or video-assisted thoracoscopic lung biopsy and 3 cases by needle lung biopsy. Histopathologically, the tumors were composed of a spectrum of cell types that included mainly centrocyte-like cells and small lymphocytes. Lymphoepithelial lesions were identified in 12 cases, reactive colliculus lymphaticus in 11 cases, follicular colonization in 10 cases, vascular infiltration in 9 cases, and pleura involvement in 4 cases. All cases showed immunoreactivity for B-cell correlative markers. Positivity for FR2 and FR3A primers in MALTLoma were found in 6 case and 5 case respectively. The detection of TCRgamma1 and TCRgamma2 was negative in 7 cases. The combined positive rate was 100%. Chemotherapy alone was administered in 3 patients, surgery alone was performed in 8 patients, and chemotherapy after operation was carried out in 6 patients. Follow-up data were available in 11 patients. Eight of them were alive and stable, one experienced relapse and two died of the disease within 11 years and 12 years after diagnosis respectively.
Conclusions: Most of the cases of pulmonary MALTLoma can be diagnosed with morphology and immunohistochemistry staining if the lesions are typical. PCR detection of IgH gene rearrangement would be helpful in differential diagnosis from benign lymphoplasia of the lung.