<正>1 Case Report The patient is a 56-year-old male who presented with infiltrative red patches on the extensor surfaces of both lower legs accompanied by pruritus for 2 years. He had previously sought treatment at another hospital, where he received traditional Chinese medicine but showed poor efficacy. He was referred to our dermatology department on February 20, 2024. Physical examination revealed infiltrative red patches on the extensor surfaces of both lower legs. The lesions were intact without ulceration, hair growth, or local hypertrophy. They had well-defined borders from surrounding tissues, limited mobility, and a deep base without tenderness or blanching upon pressure. A biopsy was recommended. Laboratory tests, including complete blood count, biochemical panel, and preoperative infectious disease screening, showed no abnormalities. Macroscopic findings of the right lower extremity lesion: an irregularly shaped gray-brown tissue block with skin, measuring 1.7 cm × 0.7 cm × 0.8 cm. The tissue was excised along the skin surface, revealing a gray-white cut surface with medium consistency and myxoid texture.