# A Case of Primary Lung Adenocarcinoma With Metastasis to Colon Harboring EGFR Exon 19 Deletion

## TL;DR

This paper presents a rare case of lung cancer that spread to the colon and highlights the importance of accurate diagnosis for proper treatment.

## Contribution

The novelty lies in documenting a rare case of lung cancer metastasis to the colon and emphasizing diagnostic approaches.

## Key findings

- Lung cancer metastasizing to the colon is extremely rare.
- Accurate diagnosis using IHC and genomic testing is crucial for proper treatment.
- GI metastases from lung cancer are uncommon, with few documented cases.

## Abstract

Lung cancer metastasizing to the colon is exceedingly rare and can present similarly to colorectal cancer. It is crucial to conduct further evaluations using immunohistochemical (IHC) stains and genomic testing to differentiate between the two and provide appropriate treatment without delay. Lung cancer generally has a poor prognosis, especially in cases with distant metastases. Although gastrointestinal (GI) metastases from lung cancer have been reported, cases of lung cancer manifesting as colon metastasis are extremely rare, with only a few instances documented.