Cutaneous Lymphatic Carcinomatosis from Lung Adenocarcinoma Presenting with Carcinoma En Cuirasse–Like Morphology

Cutaneous lymphatic carcinomatosis from lung adenocarcinoma is exceedingly rare, and its inflammatory appearance can closely mimic dermatitis or drug-related eruptions, leading to diagnostic delay. We report a case presenting with carcinoma en cuirasse–like morphology—diffuse indurated erythematous plaques with lymphangitic distribution—confirmed on biopsy to represent intralymphatic tumour emboli from metastatic lung adenocarcinoma.