2.1 History of present illness
An 18-year-old woman who suffered from left lower limb deformity and thigh pain for > 10 years was admitted to our center. Physical examination revealed lower limb discrepancy (−2.5 cm in left leg), limping gait, left groin area tenderness, and restricted range of motion in the left hip. Neither café-au-lait spots nor sexual precocity was found. X-ray and computed tomography (CT) imaging showed severe coxa varus in the left hip (femoral neck-shaft angle = 60°), varus alignment of the femur, and shepherd cane deformity (Figure 1A). Single-photon emission computed tomography (SPECT) demonstrated multiple osteolytic lesions located in craniofacial bone, left femur and left tibia (Figure 1B). Preoperative electrocardiography and chest radiography showed no positive findings. Polyostotic fibrous dysplasia was considered as the primary diagnosis. For lower limb deformity correction, proximal femur osteotomy and internal fixation of the left femur were performed after detailed preoperative planning (Figure 2A). Total operation time was 117 min and intraoperative blood loss was 800 mL. Postoperative radiography showed significant improvement of coxa varus and correction of the shepherd’s crook deformity (femoral neck-shaft angle = 104°) (Figure 2B). Total fluid replacement volume was 1850 ml in the first 24 h after surgery with restricted fluid infusion rate (40–60 drops /min). Genetic testing of the pathological bone tissue from the proximal left femur revealed mutation of c.601C>T (Figure 3). The patient was finally diagnosed with MAS according to previous studies5, 6. However, on the morning of postoperative day 2, the patient suddenly complained of chest pain, palpitation, and dyspnea without any known cause.