Cutaneous Metastatic Cancer: Carcinoma Hemorrhagiectoides Presenting as the Shield Sign

Cutaneous metastases can be either the initial presentation of an unsuspected internal neoplasm in a cancer-free individual, or the harbinger of recurrent malignancy in an oncology patient who had achieved remission of his cancer, or a sign of progressive disease in a cancer patient who is currently receiving antineoplastic treatment. The cutaneous presentation of skin metastases is pleomorphic and can mimic not only benign conditions and tumors of the skin but also infections and inflammation of the skin. Carcinoma erysipelatoides, carcinoma hemorrhagiectoides, and carcinoma telangiectoides are the three subtypes of inflammatory cutaneous metastatic cancer. The former masquerades as a cutaneous streptococcal infection whereas the latter mimics idiopathic telangiectasias. In contrast, the morphology of carcinoma hemorrhagiectoides is distinctive: it appears similar in shape to a medieval knight's shield and its presence is referred to as a positive shield sign. To the best of our knowledge, carcinoma hemorrhagiectoides has been reported in four oncology patients whose skin metastases presented with the shield sign: two men with salivary duct carcinoma and two women with breast cancer. In conclusion, the shield sign may not only be a pathognomonic clinical feature of carcinoma hemorrhagiectoides but also reflect a common genomic aberration of these metastatic tumors.