Cutaneous Metastasis of Lung Adenocarcinoma: Initially Mimicking and Misdiagnosed as Keloids

Cutaneous metastases have distinct morphologic features that can aid in making the diagnosis clinically even prior to biopsy. Lesions often have a nodular appearance and are firm, fixed, and range from flesh-colored to reddish-purple. A 73-year-old female with a history of lung adenocarcinoma status-post neoadjuvant chemotherapy and lobectomy 20 months prior was referred to our dermatology clinic for evaluation and treatment of suspected keloids on the left flank. The lesions were firm, plum-colored, fibrotic nodules, and were diagnosed clinically in the office as cutaneous metastases of internal malignancy. Punch biopsy was performed and revealed a proliferation of atypical epithelial cells arranged in cords and strands, with neoplastic cells positive for CK7 and TTF-1, confirming the diagnosis of metastatic adenocarcinoma. The patient was referred for chemotherapy and is still alive nine months following the prompt clinical diagnosis of cutaneous metastasis. Cutaneous metastasis signifies a poor prognosis, but knowledge of the clinical characteristics of these lesions can lead to earlier detection and more prompt initiation of treatment.