患者女,77岁。主因6年前发现左拇指甲下桡侧呈黑线状改变,并逐渐扩大蔓延至左拇指第一掌指关节背侧就诊。查体:左拇指远节肿胀,表皮发黑无破溃。甲下的黑色斑块高出甲床,大小约10 mm×10mm。指甲被掀起,变色、变形(图1)。边缘可见数个卫星灶。病变质韧且边界不清,触痛明显,无活动度。彩超检查:左拇指远端肿物处可见16.1mm×11.3mm×10.1mm不均匀中低回声肿物,边 Female patient, 77 years old. The main reason was found six years ago, the radial line of the left thumb was black linear change, and gradually spread to the left thumb to the first metacarpophalangeal treatment. Physical examination: swelling of the distal thumb of the left thumb, black skin without ulceration. A black plaque above the nail bed, the size of about 10 mm × 10mm. Nails were set off, discolored, deformed (Figure 1). Can be seen on the edge of several satellite stoves. Lesions quality and tough boundaries and clear, tenderness, no activity. Color Doppler ultrasound examination: the left thumb at the distal mass visible 16.1mm × 11.3mm × 10.1mm uneven hypoechoic mass, while