# Adenosquamous Cell Carcinoma Associated With Giant Lung Cyst: A Case Report

## TL;DR

A 51-year-old heavy smoker was found to have a rare adenosquamous cell carcinoma in a giant lung cyst during a health checkup, highlighting the importance of early CT scans for detection.

## Contribution

This case report highlights the rare association of adenosquamous cell carcinoma with a giant lung cyst and emphasizes early detection challenges.

## Key findings

- Adenosquamous cell carcinoma was diagnosed in a large lung cyst in a heavy smoker.
- Early detection via chest CT is crucial due to overlapping shadows from the cyst and tumor.
- Surgical complications like pneumothorax and peptic ulcer disease should be considered in such cases.

## Abstract

Emphysematous lung cysts are considered to be a risk factor for the development of lung cancer, and there have been several reports of lung cancer cases that have developed in conjunction with large lung cysts. Emphysematous lung cysts are more common in heavy smokers, and it has been pointed out that early detection is difficult because the lung mass shadow overlaps with the lung cyst, so they are often detected in an advanced state. We report a case of this disease that was discovered incidentally. The patient was a 51-year-old man. During a health checkup, he was found to have a right lung cyst and a nodular shadow in his lung. He had a history of smoking 20 cigarettes a day for 30 years, and his Brinkman Index was 600. There were no other significant findings in the medical history. In addition to emphysema, a chest computed tomography (CT) scan revealed a large lung cyst and a lobulated, irregular nodular shadow measuring 15 x 14 mm in the S2 region of the right lung. A definitive diagnosis could not be made by transbronchial biopsy. Surgery was performed with the aid of a thoracoscope. A right upper lobectomy and mediastinal lymph node dissection were performed after a needle biopsy of the tumor was diagnosed as lung adenocarcinoma by intraoperative rapid diagnosis. The histopathological examination findings were diagnosed as adenosquamous cell carcinoma, WHO Grade 3, pT2apN0cM0. The patient is currently undergoing oral chemotherapy. In this case, it is important to detect large lung cysts using early chest CT scans. In addition, when performing surgery for lung cancer with a large lung cyst, it is necessary to be aware of the possibility of complications such as pneumothorax and peptic ulcer disease on the opposite side.