# Dermal Lymphatic Carcinomatosis as a Cutaneous Metastasis From Epidermal Growth Factor Receptor-Positive Lung Adenocarcinoma: A Case Report

## TL;DR

This case report describes a rare skin manifestation of lung cancer that mimics skin inflammation and indicates disease progression.

## Contribution

The report highlights dermal lymphatic carcinomatosis as a unique cutaneous metastasis from EGFR-positive lung adenocarcinoma.

## Key findings

- A 65-year-old woman developed a cutaneous metastatic lesion during lung cancer treatment.
- The case demonstrates the diagnostic challenges of distinguishing metastases from inflammatory skin conditions.
- Cutaneous metastases may signal therapeutic resistance or disease progression in lung cancer patients.

## Abstract

Cutaneous metastases are an uncommon but clinically significant manifestation of internal malignancies. We present a rare case of dermal lymphatic carcinomatosis arising from epidermal growth factor receptor (EGFR)-positive lung adenocarcinoma, a presentation that may closely mimic inflammatory dermatoses and indicate therapeutic resistance or disease progression. We describe the clinical course of a 65-year-old woman who developed a violaceous cutaneous metastatic lesion beneath the left breast during treatment for metastatic lung adenocarcinoma. This case highlights the importance of recognizing cutaneous signs as indicators of disease progression and emphasizes the diagnostic challenges and prognostic implications of cutaneous metastases in lung cancer.