# Pulmonary Sarcomatoid (Pleomorphic) Carcinoma Presenting As Secondary Spontaneous Pneumothorax in Diffuse Cystic Lung Disease: A Case Report

## TL;DR

A rare aggressive lung cancer presented as a pneumothorax in a patient with cystic lung disease, emphasizing the need for early diagnosis and multidisciplinary care.

## Contribution

Highlights a rare presentation of pulmonary sarcomatoid carcinoma as secondary spontaneous pneumothorax in diffuse cystic lung disease.

## Key findings

- Pulmonary sarcomatoid carcinoma can present with secondary spontaneous pneumothorax in patients with diffuse cystic lung disease.
- Early tissue diagnosis and molecular profiling are critical for guiding treatment in this aggressive malignancy.

## Abstract

Pulmonary sarcomatoid carcinoma is a rare and aggressive subtype of non-small cell lung cancer associated with poor prognosis and atypical clinical presentations. Spontaneous pneumothorax as an initial manifestation is exceedingly uncommon and may obscure the underlying diagnosis, particularly in patients with diffuse cystic lung disease.

This report describes a case of pulmonary sarcomatoid (pleomorphic) carcinoma presenting with secondary spontaneous pneumothorax in the setting of diffuse cystic lung abnormalities, highlighting the diagnostic challenges encountered and the importance of maintaining suspicion for malignancy in atypical presentations. Early tissue diagnosis, multidisciplinary evaluation, and molecular profiling played key roles in guiding definitive management.

This case underscores the need to consider lung cancer in patients presenting with spontaneous pneumothorax and atypical parenchymal findings, as timely recognition may permit curative-intent treatment and biomarker-informed systemic therapy in this aggressive malignancy.