Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma: A Report of 2 Cases and Literature Review

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is indolent and progresses more slowly than other malignant lymphomas. The clinical features are not specific and the diagnosis can often be difficult. Here, we present two rare cases of pulmonary MALT lymphoma. Both patients were incidentally found lesions in the lungs with chest computed tomography during physical examination. They were finally diagnosed by pathological biopsy. One received complete resection, the other was treated with chemotherapy. There were no recurrence in the two patients during follow-up. We also review relevant literature to provide a better recognition of this disease.

Clinical Features and Survival Outcome of Early-Stage Primary Pulmonary MALT Lymphoma After Surgical Treatment

Background: We aimed to study the clinical features and survival outcomes of patients with early-stage primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma who underwent surgery.Methods: This is a retrospective, single-center study including 32 patients with early-stage primary pulmonary MALT lymphoma. Univariate and multivariate Cox analyses were performed to select independent prognostic factors. The overall survival (OS) was analyzed by the Kaplan-Meier method and was compared with the log-rank test.Results: Among the 32 patients included, there were 16 men (50.0%) and 16 women (50.0%). The average age was 59.2 years old. Ten patients had non-specific clinical symptoms including cough, expectoration, and chest pain, and four patients had B symptoms. CT images are not specific and can be shown as peripheral, central, solid, and ground glass but more peripheral (93.8%) and solid (75.0%). In prognostic analysis, univariate analysis showed that tumor stage and size were associated with relapse-free survival (RFS) and OS [hazard ratio (HR) = 1.105, 95% CI: 1.021–1.197, P = 0.011; HR = 1.211, 95% CI: 1.158–1.968, P = 0.003, respectively]. It seems to indicate that higher stage and larger size indicate a worse prognosis, but we could not find statistically significant predictors in multivariate analysis. Sublobectomy was performed in 21 (65.6) cases, lobectomy was performed in the other 11 (34.4) cases, both of them can achieve good prognosis (5-year RFS and OS are both 100%), and there is no significant difference between them.Conclusions: The clinical manifestation of early-stage primary pulmonary MALT lymphoma is not significantly specific, and surgical resection is an effective treatment.

No evidence for a pathogen associated with pulmonary MALT lymphoma: a metagenomics investigation

Mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with chronic antigen stimulation: auto-antigens or of microbial origin. Only one study suggested association between Achromobacter xylosoxidans and pulmonary MALT lymphoma. We aimed to investigate the presence of virus or any infectious agents in pulmonary MALT lymphoma by using metagenomic next-generation sequencing (mNGS).All lung samples were centrally reviewed. The t(11;18) (q21;q21) was evaluated by FISH analysis. The snap frozen large lung biopsies were analyzed by mNGS. After lung biopsies homogenization total nucleic acids (RNA and DNA) were extracted, amplified and classified according to their taxonomic assignment, after exclusion of host DNA.We included 13 samples from pulmonary MALT lymphoma (mean age: 60.3 years, 7 women, 3 with auto-immune background) and 10 controls. The diagnosis of MALT lymphoma was confirmed for the 13 samples, 3 showed API2-MALT1 translocation (23%). No evidence of the presence of a specific pathogen was clearly identified in the group of patients with pulmonary MALT lymphoma. We identified A. xylosoxidans sequence in 4/13 patients and in 4/10 controls.This study did not find evidence for a DNA or RNA virus, a fungi, a parasite or a bacteria associated with pulmonary MALT lymphoma either in the stroma or in tumor cells.

No evidence for a pathogen associated with pulmonary MALT lymphoma: a metagenomics investigation

Mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with chronic antigen stimulation: auto-antigens or of microbial origin. Only one study suggested association between Achromobacter xylosoxidans and pulmonary MALT lymphoma. We aimed to investigate the presence of virus or any infectious agents in pulmonary MALT lymphoma by using metagenomic next-generation sequencing (mNGS).All lung samples were centrally reviewed. The t(11;18) (q21;q21) was evaluated by FISH analysis. The snap frozen large lung biopsies were analyzed by mNGS. After lung biopsies homogenization total nucleic acids (RNA and DNA) were extracted, amplified and classified according to their taxonomic assignment, after exclusion of host DNA.We included 13 samples from pulmonary MALT lymphoma (mean age: 60.3 years, 7 women, 3 with auto-immune background) and 10 controls. The diagnosis of MALT lymphoma was confirmed for the 13 samples, 3 showed API2-MALT1 translocation (23%). No evidence of the presence of a specific pathogen was clearly identified in the group of patients with pulmonary MALT lymphoma. We identifiedA. xylosoxidans sequence in 4/13 patients and in 4/10 controls.This study did not find evidence for a DNA or RNA virus, a fungi, a parasite or a bacteria associated with pulmonary MALT lymphoma either in the stroma or in tumor cells.

No Evidence for a Pathogen Associated With Pulmonary MALT Lymphoma: A Metagenomics Investigation

Mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with chronic antigen stimulation: auto-antigens or of microbial origin. Only one study suggested association between Achromobacter xylosoxidans and pulmonary MALT lymphoma. We aimed to investigate the presence of virus or any infectious agents in pulmonary MALT lymphoma by using metagenomic next-generation sequencing (mNGS).All lung samples were centrally reviewed. The t(11;18) (q21;q21) was evaluated by FISH analysis. The snap frozen large lung biopsies were analyzed by mNGS. After lung biopsies homogenization total nucleic acids (RNA and DNA) were extracted, amplified and classified according to their taxonomic assignment, after exclusion of host DNA.We included 13 samples from pulmonary MALT lymphoma (mean age: 60.3 years, 7 women, 3 with auto-immune background) and 10 controls. The diagnosis of MALT lymphoma was confirmed for the 13 samples, 3 showed API2-MALT1 translocation (23%). No evidence of the presence of a specific pathogen was clearly identified in the group of patients with pulmonary MALT lymphoma. We identified A. xylosoxidans sequence in 4/13 patients and in 4/10 controls.This study did not find evidence for a DNA or RNA virus, a fungi, a parasite or a bacteria associated with pulmonary MALT lymphoma either in the stroma or in tumor cells.

Association of Pulmonary MALT Lymphoma and Sarcoidosis

Introduction Sarcoidosis is a systemic granulomatous disease of unknown etiology characterized by the chronic inflammation. Mucosa associated lymphoid tissue (MALT) lymphoma is a low-grade marginal zone B-cell lymphoma of MALT often etiologically associated with chronic inflammation in the underlying organ. A rare association between sarcoidosis and MALT lymphoma has been reported. Case Description We present the case of a 75-year-old woman who presented with chronic cough and dyspnea of several years' duration. She was found to have fluctuating lung infiltrates on serial imaging studies. A bronchial biopsy revealed chronic inflammation, and no evidence of infection. She was then treated with oral steroids with a transient benefit. However, the infiltrate and symptoms recurred, therefore 8 months later, she underwent repeat imaging. This showed a relapse of the infiltrate and enlarged mediastinal lymphadenopathy. The lung infiltrate was biopsied (percutaneously). This demonstrated a MALT lymphoma. Imaging studies done for staging showed a large retroperitoneal lymph node. A biopsy of this node revealed non-caseating granulomas, consistent with sarcoidosis. Chemotherapy with bendamustine and rituximab was initiated for therapy of the MALT lymphoma. Discussion A rare association between pulmonary MALT lymphoma and underlying inflammation caused by sarcoidosis has been previously described. In our patient, sarcoidosis was diagnosed in a biopsy of a retroperitoneal lymph node, but we suspect that there is likely involvement of the mediastinal nodes. Disclosures Rao: Bayer & Daiichi Sankyo:Consultancy.Daniel:GSK:Other: Paid speaker for COPD medications.