Zosteriform skin metastasis of lung cancer.

Skin metastasis from internal organ malignancy has a 5% to about 10% incidence, and zosteriform metastasis is much rarer. We present the case of a 51-year-old male smoker initially given a diagnosis of right lower lung adenocarcinoma T2N3M0 who developed new-onset zosteriform skin metastasis over the right-side T3∼T5 dermatomes documented by skin biopsy specimen. The probable mechanism for this band-distributed skin metastasis is the retrograde flow of lymph after obstruction by cancer cells. Such a phenomenon may be demonstrated by lymphoscintigraphy.