Scalp metastasis of advanced gastric cancer.

Head and neck cutaneous metastasis of advanced gastric cancer is uncommon, and scalp metastasis is particularly rare. We present the case of a 60-year-old man who was diagnosed with cutaneous metastasis on the scalp originating from advanced gastric cancer. The patient was referred to the plastic surgery department for a scalp mass near the hairline. He had been diagnosed with advanced gastric cancer and undergone total gastrectomy and Roux esophagojejunostomy 3 years previously. The differential diagnosis for a single flesh-colored nodule on the scalp included benign tumors such as epidermal cyst or lipoma; therefore, the patient underwent excision and biopsy. In the operative field, the mass was found to be located in the frontalis muscle. The biopsy result showed that the mass was a metastatic lesion of advanced gastric cancer. Whole-body computed tomography revealed a gastric tumor with blood vessel infiltration, peritoneal carcinomatosis, liver metastasis, and multiple disseminated subcutaneous metastases. Although scalp metastasis originating from an internal organ is extremely rare, plastic surgeons should always consider a metastatic lesion in the differential diagnosis if a patient with a scalp lesion has a history of malignant cancer.