A Rash That Wasn't Benign: Cutaneous Lymphangitic Carcinomatosis as an Atypical Presentation of Metastatic Gastric Adenocarcinoma.

Cutaneous metastases from internal malignancies are uncommon and are particularly rare in gastric adenocarcinoma. When they occur, they typically present as firm nodules on the thorax, abdomen, or umbilicus. Cutaneous lymphangitic carcinomatosis is an especially uncommon metastatic pattern and may clinically mimic a variety of dermatoses. A man in his 70s with metastatic gastric adenocarcinoma presented with diffuse violaceous, indurated plaques, and histopathologic examination confirmed cutaneous lymphangitic carcinomatosis. This case highlights a rare presentation of gastric adenocarcinoma with extensive cutaneous lymphangitic involvement.