例一,男,50岁。右大腿背侧及肘部暗红色斑块渐增大5年、发痒3年。入院时斑块分别为7×6cm~2及0.5×7cm~2,暗红色,卵圆形,不高出皮面,边界清楚,表面干燥且有白色脱屑,斑块质地硬。例二,男、44岁。22年前于右胸壁发现2×2cm~2圆形暗红色斑块,略高出皮面。感痒,曾诊断为“皮肤癣”,外用“癣药水”、局 Case 1, male, 50 years old. The dark red patches on the dorsal and elbow of the right thigh gradually increased for 5 years and itching for 3 years. On admission, the plaques were 7×6cm~2 and 0.5×7cm~2, dark red, oval, not higher than the surface of the skin, the boundary was clear, the surface was dry and there was white desquamation, and the plaque was hard. Case 2, male, 44 years old. Twenty-two years ago, a 2×2cm~2 round dark red plaque was found on the right chest wall, slightly higher than the skin. Itching, once diagnosed as “skin blemishes”, external use “boilers”, bureau