Abstract：
An aneurysmal bone cyst (ABC) is a benign bone neoplasm that typically occurs during the first and second decades of life. ABC usually presents as a rapidly growing intramedullary expansile mass with multiple blood-filled cysts in the metaphysis of the long tubular bones. Here, we report a case of a periosteal solid ABC that was initially diagnosed as a high-grade surface osteosarcoma. A 10-year-old male was referred to our hospital for swelling and tenderness of the left upper arm. Radiography revealed periosteal mass without fluid-fluid levels. On performing open biopsy, the tumor showed hypercellular proliferation of uniform spindle to epithelioid cells with brisk mitotic activity (up to 12/2 mm2) and lace-like osteoid formation, which was diagnosed as a high-grade surface osteosarcoma. After one course of chemotherapy using adriamycin and cisplatin, peripheral sclerosis was conspicuous, which led to pathological review and revision of diagnosis as \"possibly osteoblastoma.\" The patient was disease-free for 4 years after marginal resection and curettage. Retrospective nanopore DNA sequencing unexpectedly detected a PAFAH1B1::USP6 rearrangement. The fusion gene was further validated using reverse transcription-polymerase chain reaction and the diagnosis was revised to ABC. Chromothripsis involving chromosome 17 has also been identified. Methylation analysis classified the present tumor as an ABC or non-ossifying fibroma using t-distributed stochastic neighbor embedding and unsupervised hierarchical clustering. This case report highlights the utility of nanopore DNA sequencing for soft tissue and bone tumor diagnosis.
摘要：
动脉瘤性骨囊肿（ABC）是一种良性骨肿瘤，通常发生在生命的第一个和第二个十年。ABC通常表现为快速生长的髓内膨胀性肿块，在长管状骨的干phy端有多个充满血液的囊肿。这里,我们报告一例骨膜实性ABC,最初诊断为高级别表面骨肉瘤.一名10岁男性因左上臂肿胀和压痛被转诊到我们医院。X线摄影术显示骨膜肿块没有液体水平。在进行开放式活检时，肿瘤显示均匀纺锤体向上皮样细胞的高细胞增殖，有丝分裂活动活跃（高达12/2mm2）和蕾丝样类骨质形成，被诊断为高级别表面骨肉瘤。在使用阿霉素和顺铂进行一个疗程的化疗后，周围硬化明显，这导致病理检查和修订诊断为“可能是骨母细胞瘤”。“患者在边缘切除和刮宫后4年内无病。回顾性纳米孔DNA测序意外地检测到PAFAH1B1::USP6重排。使用逆转录-聚合酶链反应进一步验证融合基因，并将诊断修改为ABC。还鉴定了涉及17号染色体的嗜铬杆菌病。甲基化分析使用t分布随机邻居嵌入和无监督分层聚类将本肿瘤分类为ABC或非骨化性纤维瘤。本病例报告重点介绍了纳米孔DNA测序在软组织和骨肿瘤诊断中的应用。
