von Borstel Donald, A Taguibao Roberto, A Strle Nicholas, E Burns Joseph
Department of Radiology, Oklahoma State University Medical Center, 744 W 9th Street, Tulsa, OK, 74127, USA.
Department of Pathology, University of California, Irvine, UCI Medical Center, 101 The City Dr. South, Route 140, Orange, CA, 92868, USA.
Skeletal Radiol. 2017 Apr;46(4):571-578. doi: 10.1007/s00256-017-2588-7. Epub 2017 Feb 11.
Giant cell tumor of the bone (GCTB) is a locally aggressive benign tumor, which has historically been treated with wide surgical excision. We report a case of a 29-year-old male with histology-proven GCTB of the distal ulna. The initial imaging study was a contrast-enhanced magnetic resonance imaging (MRI) examination of the left wrist, which was from an outside facility performed before presenting to our institution. On the initial MRI, the lesion had homogenous T2-hyperintense and T1-hypointense signal with expansive remodeling of the osseous contour. A radiographic study performed upon presentation to our institution 1 month later showed progression of the lesion with atypical imaging characteristics. After confirming the diagnosis, denosumab therapy was implemented allowing for reconstitution of bone and intralesional treatment. The patient was treated with five doses of denosumab over the duration of 7 weeks. Therapeutic changes of the GCTB were evaluated by radiography and a post-treatment MRI. This MRI was interpreted as suspicious for worsening disease due to the imaging appearance of intralesional signal heterogeneity, increased perilesional fluid-like signal, and circumferential cortical irregularity. However, on subsequent intralesional curettage and bone autografting 6 weeks later, no giant cells were seen on the specimen. Thus, the appearance on the MRI, rather than representing a manifestation of lesion aggressiveness or a non-responding tumor, conversely represented the imaging appearance of a positive response to denosumab therapy. On follow-up evaluation, 5 months after intralesional treatment, the patient had recurrent disease and is now scheduled for wide-excision with joint prosthesis.
骨巨细胞瘤（GCTB）是一种局部侵袭性良性肿瘤，传统上采用广泛手术切除治疗。我们报告一例29岁男性，经组织学证实为尺骨远端骨巨细胞瘤。最初的影像学检查是对左腕进行的对比增强磁共振成像（MRI）检查，该检查由外院在患者转诊至我院之前完成。在最初的MRI上，病变呈均匀的T2高信号和T1低信号，伴有骨轮廓的膨胀性重塑。1个月后患者转诊至我院时进行的X线检查显示病变进展，具有非典型影像学特征。确诊后，实施地诺单抗治疗以促进骨重建并进行瘤内治疗。患者在7周内接受了5剂地诺单抗治疗。通过X线和治疗后的MRI评估GCTB的治疗变化。该MRI被解读为可疑疾病恶化，因为瘤内信号不均匀、瘤周液样信号增加以及周围皮质不规则等影像学表现。然而，6周后随后进行的瘤内刮除和自体骨移植术中，标本上未见到巨细胞。因此，MRI上的表现并非代表病变侵袭性或无反应性肿瘤的表现，相反，它代表了对地诺单抗治疗阳性反应的影像学表现。在随访评估中，瘤内治疗5个月后，患者疾病复发，现计划进行广泛切除并植入关节假体。
