Diagnosis and differential diagnosis of primary pulmonary MALT lymphoma
ZHANG Feng-mei
LI Yun
ZHU Ya-qing
Abstract：Objective To explore the clinical pathological features, immunohistochemical manifestations, differential diagnosis, treatment, and prognosis of primary pulmonary mucosa-associated lymphoid tissue (MALT) extranodal marginal zone B-cell lymphoma. Methods The clinical data, imaging findings, and pathological characteristics of a 72-year-old female patient with pulmonary MALT lymphoma were analyzed, and related literature was discussed. Surgical specimens were fixed, dehydrated, and embedded in paraffin, followed by HE staining and immunohistochemical analysis. Results The lesion was mainly composed of small lymphoid cells, with local nodular or diffuse proliferation, and tumor cells infiltrated around small airways and alveolar septa. Immunohistochemistry showed CD20 and CD79a positivity, strong Bcl-2 positivity, and negativity for CD3, CD5, and Cyclin D1, with a Ki-67 proliferation index of approximately 20%. The exclusionary diagnosis of this disease requires differentiation from other types of small B-cell lymphomas, such as follicular lymphoma, mantle cell lymphoma, and small lymphocytic lymphoma. Conclusion Primary pulmonary MALT lymphoma is a rare low-grade malignant B-cell lymphoma. Its clinical presentation is atypical and requires pathological and immunohistochemical analysis for confirmation. Early diagnosis and individualized treatment are crucial for improving prognosis, and regular follow-up helps detect malignant transformation early, thereby improving patients' long-term survival rates.
Keywords：Primary pulmonary mucosa-associated lymphoid tissue extranodal marginal zone B-cell lymphomaImmunohistochemistryPathological featuresDifferential diagnosisTreatment and prognosis
Publication Date：2025-03-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：3( 313-315 )