Cutaneous lymphangitis carcinomatosa: a unique presentation of a rare disease.

A 75-year-old man with a three-year history of metastatic lung adenocarcinoma was diagnosed with cutaneous lymphangitic carcinomatosa of unique morphology. He was admitted to our hospital for right neck swelling, erythema, and failure to thrive. Skin examination demonstrated an indurated, thickened, firm, hyperpigmented plaque extending from the right neck and chest to the right ear, cheek, and eyelids. Skin biopsy demonstrated poorly differentiated adenocarcinoma, morphologically consistent with metastasis from the patient's known pulmonary adenocarcinoma and showed dermal invasion, perineural invasion, and involvement of dermal lymphatics. The diagnosis was an atypical presentation of cutaneous lymphangitis carcinomatosa from metastatic lung adenocarcinoma. This case presentation affirms that cutaneous lymphangitis carcinomatosa has a variety of atypical presentations, so physicians must maintain a high index of suspicion when evaluating cutaneous lesions in patients with known or suspected internal malignancy.