Dermoscopic findings in cutaneous metastases.

IMPORTANCE: Cutaneous metastases rarely develop in patients with cancer but have important implications for prognosis and treatment. While dermoscopy is useful for many skin lesions, few data exist regarding dermoscopic findings in cutaneous metastases. OBSERVATIONS: We reviewed high-quality dermoscopic images of 20 outpatients with biopsy-proven cutaneous metastases and known diagnosis of underlying visceral malignancy and correlated these findings with clinical and histologic data. Most lesions were pink or flesh-colored, but 3 of 20 were pigmented. All 17 nonpigmented lesions demonstrated a vascular pattern on dermoscopy, with 15 of 17 (88%) having discrete vessels and 2 of 17 (12%) showing pink homogeneous structureless areas. Serpentine, or linear irregular, vessels were most common. In the 3 pigmented lesions (all metastatic breast carcinoma), various melanocytic patterns were observed. CONCLUSIONS AND RELEVANCE: Dermoscopically visible vascular structures within a cutaneous nodule in patients with a known cancer diagnosis should raise suspicion for cutaneous metastasis. Pigmentation in such lesions, in the absence of a history of melanoma, suggests a primary breast carcinoma. The high prevalence of vascular structures among cutaneous metastases may suggest a role for angiogenesis in their pathogenesis. These findings support the use of dermoscopy in the evaluation of suspected skin metastases or in the assessment of lesions of unknown origin in patients with cancer.