一位 8 岁男性患儿出现右腿新发急性疼痛。X 线示无移位性骨折（图 A）和股骨远端骨干倒置管形，即常说的锥形瓶畸形（图 B）。患儿即往有神经母细胞瘤病史7年余（患儿 6 月龄大时确认为神经母细胞瘤），神经母细胞瘤进行性发展，5年前经环磷酰胺和每月一次双膦酸盐化疗后神经母细胞瘤缓解。双膦酸盐治疗停止 18 月后因为担心骨硬化症而中止治疗。实验室检查，X 线检查和遗传学检查未有任何遗传或其他原因所致的获得性骨疾病发现，如原发性骨髓疾病，重金属中毒，骨代谢疾病以及其他发育不良等。
Osteopetrosis and Erlenmeyer-Flask Deformity
An 8-year-old boy presented with new-onset acute pain in his right leg. Radiographs showed a nondisplaced fracture (Panel A) and undertubulation of the distal femoral diaphysis — a condition known as Erlenmeyer-flask deformity (Panel B). He had a history of neuroblastoma, which was diagnosed when he was 6 months of age; the disease progressed after standard chemotherapy but had been in remission for the 5 years before this presentation, after treatment with cyclophosphamide and monthly intravenous bisphosphonate therapy. Bisphosphonate therapy was discontinued after 18 months because of concern about osteopetrosis on routine radiographic imaging. Laboratory testing, imaging, and genetic testing did not reveal any hereditary or other common causes of acquired bone disease, including primary bone marrow disorders, heavy-metal poisoning, bone metabolic diseases, and other dysplasias. The delineation between osteopetrotic and normal bone (Panel B) suggested a period of increased bone turnover followed by improved bone growth. This finding is more consistent with bisphosphonate exposure than with an underlying genetic condition. The patient remains at risk for fractures in transition areas between osteopetrotic and normal bone. It was recommended that he avoid contact sports and continue annual follow-up; 18 months later, he has had no new symptoms or fractures.
Osteopetrosis and Erlenmeyer-Flask Deformity. N Engl J Med 2015; 373:e12 September 3, 2015DOI: 10.1056/NEJMicm1407743