# Endoscopic ultrasound-guided fine-needle aspiration in diagnosing primary medistinal large B-cell lymphoma: a case report

## TL;DR

A minimally invasive technique called EUS-FNA was successfully used to diagnose a rare type of lymphoma in a patient with a mediastinal tumor.

## Contribution

This case report highlights the effectiveness of EUS-FNA in diagnosing primary mediastinal large B-cell lymphoma.

## Key findings

- EUS-FNA provided accurate tissue samples for diagnosing PMBCL in a mediastinal mass.
- The technique is safe, repeatable, and suitable for diagnosing mediastinal tumors.
- Combining EUS-FNA with transbronchoscope biopsy enabled a clear diagnosis of lymphoma.

## Abstract

Mediastinal tumors present diagnostic challenges due to their unique location. This case report presents a patient diagnosed with primary mediastinal large B-cell lymphoma (PMBCL) using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA), demonstrating the utility of this minimally invasive technique in detecting and confirming PMBCL.

A 34-year-old previously healthy woman came to our hospital complaining of dysphagia for 3 months. The gastroscopy showed a huge submucosal bulge in the middle of the esophagus, and a contrast-enhanced computed tomography scan of the chest revealed a left main bronchus nodule measuring 15 mm, mediastinal lymph node enlargement, and fusion with necrosis. Subsequently, we obtained the tissue from the mediastinal mass through EUS-FNA and the tissue from the left main bronchus nodule through transbronchoscope biopsy. According to the pathologic findings, we made a clear diagnosis: primary mediastinal large B-cell lymphoma.

As a minimally invasive technique, EUS-FNA is highly safe, repeatable, and accurate for lymphoma diagnosis. Although there are some limitations, it can play an important role in diagnosing mediastinal tumors.