软骨母细胞瘤骨膜反应的影像学及临床病理研究

Imaging and clinicopathological manifestations periosteal reaction in chondroblastoma

目的软骨母细胞瘤(chondroblastoma,CB)骨膜反应影像与病理变化的研究,文献报道不多。文中观察CB的影像学、组织学及免疫表型变化,为肿瘤诊断提供病理依据。方法回顾性分析67例CB的临床及影像学资料,根据组织学和免疫组织化学,重点观察骨膜反应的基本病变。结果 67例中32例出现骨膜反应(47.8%),发生在长骨25例,扁骨7例。20例位于骨骺和骨端附近,其中髋关节周围17例,占53.1%。29例X线片示软组织肿胀,脂肪线模糊变形。25例CT检查见骨膜反应环绕肿瘤膨胀区外缘,局部形成线状或薄层骨质增生,4例出现皮质断裂或塌陷,3例形成软组织肿块。13例MRI显示长骨骨膜反应与骨皮质平行的薄层长T1、短T2信号,并可见骨皮质旁细线状高信号,横轴位上皮质低信号伴周围软组织的中等信号。组织学上骨膜反应的表现多种形态,其中32例见骨膜水肿,纤维组织和血管增生,18例表现多量炎细胞浸润并见形成淋巴滤泡,9例表现滑膜炎及17例层状骨膜新生骨形成。免疫组化显示CD34、CD105血管阳性,D2-40淋巴管阳性,未见肿瘤累及脉管。结论软骨母细胞瘤的层状骨膜反应常见,具有其特征性变化,认识其基本病理变化有助于软骨母细胞瘤的诊断。

Objective Few reports are seen on the imaging and pathological changes of periosteal reaction in chondroblastomas （CB）. This study was to investigate the imaging, histopathological and immunohistochemical changes of CB and provide some evidence for its diagnosis. Methods We retrospectively analyzed the clinical and imaging data of 67 cases of CB and observed the morphological and immunohistochemical changes of periosteal reaction. Results Of the 67 cases, periosteal reaction occurred in 32 （47.8%）, including 25 on the long bones and 7 on the flat bones. Most lesions were on the epiphyses or apophses, 17 cases （53.1%） around the hip joints. X-ray plain films showed soft tissue swelling in 29 cases, with the subcutaneous/intramuscular-fat space fuzzy and deformed. CT displayed in 25 cases threadlike thin layers of periosteal proliferation with sclerotic border encircling the tumor, 4 with collapsed focal bone cortexes and 3 with soft tissue masses. MRI demonstrated the fine findings of PR as hyperintense signals on both T1W1 and T2W1, sometimes with low-intensity signals on the axis of the long bone and some intermediate signals in the periosteal soft tissue. Histologically, periosteal edema with fibrovascular proliferation was revealed in 32 cases, inflammatory cell reaction with lymph follicle formation in 18, synovitis in 9, and lamellated periosteal new bone formation in 17. I mmunohistochemically, no vascular and lymphatic vessel infiltration was observed in the cases of CD34, CD105 and D2-40 positive. Conclusion CB is rare but its periosteal reaction quite common and with characteristic changes. An insight into the basic pathological changes of the periosteal reaction contributes to the correct diagnosis of CB.