# Lung adenocarcinoma discovered during the follow-up of lung-dominant connective tissue disease: a case report and literature review

## TL;DR

This case report highlights the challenges of diagnosing lung cancer in patients with lung-dominant connective tissue disease.

## Contribution

The paper presents a case of lung adenocarcinoma in a patient with LD-CTD and reviews relevant literature on differential diagnosis.

## Key findings

- An 80-year-old woman with LD-CTD developed lung adenocarcinoma despite treatment with nintedanib.
- Progressive symptoms and imaging changes raised suspicion of lung cancer in the patient.
- The study emphasizes the need for vigilance in diagnosing lung cancer in LD-CTD patients with atypical progression.

## Abstract

Interstitial lung disease (ILD) can lead to lung cancer, which brings great challenges to differential diagnosis and comprehensive treatment. However, the clinical features of lung-dominant connective tissue disease (LD-CTD) related ILD combined with lung cancer has not been validated. We report the case of an 80-year-old woman with LD-CTD treated regularly with nintedanib who presented progressive dyspnoea and hypoxemia after recurrent viral infections. Her chest computed tomography (CT) showed aggravated interstitial fibrosis in both lower lungs with moderate right pleural effusion. Clinicians should be alert to lung cancer in patients who are experiencing poor responsiveness to treatment or acute progression of ILD. The available literatures about the differential diagnosis of clinical manifestations, imaging, treatment and prognosis of LD-CTD are reviewed and discussed in this study.