Abstract 354: Conditional inactivation of Pten and overexpression of EGFR in Schwann cells results in early high-grade peripheral nerve sheath tumor development

Thymus and lung mucosa-associated lymphoid tissue lymphoma with adenocarcinoma of the lung: a case report and literature review

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a common, low-grade, malignant B-cell lymphoma. However, simultaneous MALT lymphoma in the thymus and lung is extremely rare, and concomitant adenocarcinoma of the lung is even rarer. Herein, we report a rare case of a collision tumor in which MALT lymphoma was found in both the thymus and lung with Sjögren's syndrome (SS) and adenocarcinoma in the lung.

CASE PRESENTATION

A physical examination of a 32-year-old woman revealed an anterior superior mediastinal space-occupying lesion, and chest computed tomography (CT) indicated a nodular ground-glass opacity and irregular mixed-density focus in the right lung. All lung cancer-related tumor biomarkers were within normal ranges. The thymus and part of the lung tissue were surgically resected. The histopathology and molecular examinations confirmed MALT lymphoma of the thymus and lung with lung adenocarcinoma. SS was also diagnosed. No special postoperative treatment was performed for the MALT lymphoma, and the patient underwent immunosuppressive therapy for SS after 4 months of follow-up observation.

CONCLUSIONS

MALT lymphoma of the thymus and lung tissues has no specific presentation on imaging and is difficult to differentiate from common malignant tumors, and the definite diagnoses of these tumors are highly dependent on histopathological examination in combination with molecular testing and cytogenetics. SS may be an important potential condition for the occurrence of MALT lymphoma in the thymus and lung. Additional similar cases are needed to clarify the biological pathways and potential molecular mechanisms of rare lymphomas and collision tumors.

Primary thymic MALT lymphoma in a patient with Sjögren's syndrome and multiple lung cysts: a case report

Background

Thymic mucosa-associated lymphoid tissue (MALT) lymphoma is rare and also known for its association with autoimmune diseases, especially Sjögren’s syndrome (SjS), which could affect the systemic organs, and pulmonary involvement often reveals multiple lung cysts.

Case presentation

A 40-year-old woman presented with an anterior mediastinal mass and multiple lung cysts on computed tomography. We suspected thymoma concomitant with lymphangioleiomyomatosis and performed a total thymectomy and wedge resection of the lung as a surgical biopsy. The histopathological diagnosis of the mediastinal mass was a MALT lymphoma, and there were no specific findings in the lung specimen. She had a history of SjS, which had been overlooked during the initial work-up.

Conclusions

A history of SjS should raise suspicion of a MALT lymphoma for the differential diagnosis of an anterior mediastinal mass. A precise history taking is crucial for the correct diagnosis, and we could have avoided a lung resection in our case.