Desai Ketav, Liu Shiguang, Baskovich Brett, Makary Raafat
Pathology, University of Florida College of Medicine - Jacksonville, Jacksonville, USA.
Pathology and Laboratory Medicine, University of Florida College of Medicine - Jacksonville, Jacksonville, USA.
Cureus. 2022 Sep 13;14(9):e29105. doi: 10.7759/cureus.29105. eCollection 2022 Sep.
Dedifferentiated chondrosarcoma (DDCS) is a rare entity, constituting only 1-2% of all primary bone tumors, and has a dismal prognosis. Nearly two-thirds of the primary tumors of DDCSs are found in the appendicular skeleton, mostly involving the femur, humerus, and pelvis. DDCS of the small bones of the hand and foot are exceedingly rare with only four cases documented in the literature so far. In this report, we present a case of a 91-year-old woman with a rapidly growing bone tumor initially thought to be a trigger finger, which, on histologic examination of the amputation, turned out to be DDCS. On a follow-up CT scan, multiple pulmonary metastases were identified. Next-generation sequencing identified isocitrate dehydrogenase 2 () (p.R172S, c.516G>T), (c.-146C>T), and (c.559+1G>A) mutations. Microsatellite instability was equivocal and tumor mutation burden was low. Due to the advanced age of the patient, she was given palliative treatment and was alive at the six-month follow-up.
去分化软骨肉瘤（DDCS）是一种罕见的疾病，仅占所有原发性骨肿瘤的1%-2%，预后较差。近三分之二的DDCS原发性肿瘤位于四肢骨骼，主要累及股骨、肱骨和骨盆。手足小骨的DDCS极为罕见，迄今为止文献中仅记载了4例。在本报告中，我们介绍了一例91岁女性患者，其患有一个生长迅速的骨肿瘤，最初被认为是扳机指，在截肢后的组织学检查中发现是DDCS。在后续的CT扫描中，发现了多处肺转移。二代测序鉴定出异柠檬酸脱氢酶2（IDH2）（p.R172S，c.516G>T）、TERT（c.-146C>T）和ATRX（c.559+1G>A）突变。微卫星不稳定性不明确，肿瘤突变负荷较低。由于患者年龄较大，给予了姑息治疗，在六个月的随访时仍存活。
