Malignant eccrine spiradenoma is a rare neoplasm generally arising from long-standing benign eccrine spiradenomas; it is rarely seen on the scalp. A 27-year-old woman with a malignant eccrine spiradenoma of the scalp, which had occurred 8 months after the inadequate excision of a benign eccrine spiradenoma, was treated at our hospital. The patient underwent lymphoscintigraphy. A biopsy of the sentinel lymph nodes in the right periparotid and left occipital regions was performed, and the nodes showed no metastases. The tumor with its large subcutaneous extension and the outer table of the cranium were removed. A split-thickness skin graft was applied on the exposed inner table. At 24 months' follow-up, there has been no tumor recurrence. We report a case of a malignant eccrine spiradenoma of the scalp with cranial involvement that arose from an inadequately removed, longstanding, benign eccrine spiradenoma in a young patient. Also, we review the existing literature on malignant eccrine spiradenoma of the scalp.