# Rapidly Progressive Primary Pulmonary Leiomyosarcoma Diagnosed by Endobronchial Ultrasound‐Guided Transbronchial Needle Aspiration: A Case Report

## TL;DR

A rare lung cancer case was diagnosed using a specialized biopsy technique, showing its usefulness in identifying difficult-to-diagnose tumors.

## Contribution

Demonstrates the effectiveness of EBUS-TBNA in diagnosing primary pulmonary leiomyosarcoma.

## Key findings

- EBUS-TBNA successfully diagnosed primary pulmonary leiomyosarcoma from a mediastinal lymph node.
- The disease progressed rapidly despite treatment, leading to death within four months.
- Brain metastasis was detected and treated with Gamma Knife radiosurgery and chemotherapy.

## Abstract

Primary pulmonary leiomyosarcoma (PPL) is a rare malignant tumour with a poor prognosis, particularly in unresectable cases. We report the case of an 82‐year‐old man who was referred for evaluation of an incidental chest abnormality. Chest computed tomography (CT) revealed a nodule in the left upper lobe and enlargement of the 4L lymph node. An initial bronchoscopic biopsy was inconclusive; however, leiomyosarcoma was subsequently diagnosed using endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) of the lymph node. The patient later developed a solitary brain metastasis detected by brain computed tomography and was treated with Gamma Knife radiosurgery, followed by chemotherapy. Despite treatments, the disease progressed rapidly, and the patient died 4 months after the initial diagnosis. This case highlights the diagnostic value of EBUS‐TBNA in obtaining adequate tissue for definitive diagnosis of rare pulmonary sarcomas and illustrates the aggressive clinical course of PPL with brain metastasis.

Primary pulmonary leiomyosarcoma is a rare malignant tumour that is often difficult to diagnose. We report a case that was successfully diagnosed using endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) of a mediastinal lymph node. This case highlights the diagnostic value of EBUS‐TBNA in rare pulmonary sarcomas.