# Adenocarcinoma originating in the anterior mediastinum diagnosed by endobronchial ultrasound-guided transbronchial cryobiopsy: a case report

## TL;DR

A rare adenocarcinoma in the anterior mediastinum was successfully diagnosed using endobronchial ultrasound-guided transbronchial cryobiopsy.

## Contribution

This case report highlights the effectiveness of EBUS-cryobiopsy in diagnosing mediastinal tumors with minimal tissue damage.

## Key findings

- EBUS-cryobiopsy provided sufficient specimen quality for a definitive histopathological diagnosis.
- The tumor was distinct from the patient's prior breast cancer, indicating a separate origin.
- EBUS-cryobiopsy is a safe and effective alternative to CT-guided biopsies in complex anatomical regions.

## Abstract

Endobronchial ultrasound-guided transbronchial cryobiopsy (EBUS-cryobiopsy) is advantageous for collecting larger specimens with minimal crushing; however, it has not been widely used for mediastinal tumors.

A 73-year-old woman with a history of left breast cancer underwent surgery followed by radiotherapy. Computed tomography showed a mass in the anterior mediastinum that was in extensive contact with the sternum on the ventral side and partly with the trachea on the dorsal side. Two computed tomography-guided needle biopsies (CTNBs) were performed on the mass; however, a definitive diagnosis was not made because of severe crush artifacts. Subsequently, we performed EBUS-cryobiopsy and safely obtained sufficient specimen volume with minimal crushing. The histopathological diagnosis was adenocarcinoma, with immunobiological features distinct from those of previous breast cancers. Her overall diagnosis was a rare tumor originating in the anterior mediastinum.

EBUS-cryobiopsy can be safely performed in narrow areas surrounded by major blood vessels, and the obtained specimens may be superior to CTNBs for histopathological diagnosis.