Skin metastasis as the first manifestation of lung carcinoma.

Lung cancer is the most frequently diagnosed non-skin cancer and has a high mortality rate. Skin metastases that manifest as visceral malignancies are rare. Cutaneous metastasis from lung cancer has been observed in only 0.22%-12% of cases and is rarely the first manifestation of lung cancer. The histopathological features of metastases are occasionally difficult to distinguish from those of primary cutaneous tumors, despite the rigorous application of useful techniques, particularly immunohistochemistry. We report 3 asymptomatic cases of men who presented with solitary periumbilical, sacral, and scalp metastasis as the first manifestation of an underlying malignant lung tumor.