Franchi Alessandro, Bacchini Patrizia, Della Rocca Carlo, Bertoni Franco
Department of Human Pathology and Oncology, University of Florence, Florence, Italy.
Mod Pathol. 2004 Mar;17(3):288-91. doi: 10.1038/modpathol.3800069.
Central low-grade osteosarcoma is an uncommon form of osteosarcoma, which is often difficult to distinguish from benign bone lesions. We reviewed the radiographic studies, the histologic material and the clinical records of two patients with central low-grade osteosarcoma that closely simulated the histologic appearance of Paget's disease of bone. The patients were two women aged 46 and 53 years. Radiologically, they presented a large ill-defined densely sclerotic lesion involving the proximal tibia. Both lesions only focally presented the conventional histologic appearance of central low-grade osteosarcoma, with a proliferation of fibroblast-like cells embedded in a dense collagenous stroma and irregular anastomosing tumor bone trabeculae. The most striking feature was the presence of extremely thickened irregular plates of bone with an irregular mosaic pattern of cement lines that closely resembled that of Paget's disease of bone. One patient, who had been initially treated for Paget's disease for 7 years, experienced disease progression. At resection of proximal tibia, there was evidence of dedifferentiation to high-grade osteosarcoma. After 2 months, she developed local recurrence that was treated with above-knee amputation, followed by chemotherapy. She died with multiple lung metastases 4 months later. The other patient is alive 9 months after wide tumor resection. These cases further expand the spectrum of central low-grade osteosarcoma, and underscore the diagnostic difficulties in separating central low-grade osteosarcoma from benign bone diseases, which may lead to delay in diagnosis, inadequate treatment, and eventually to dedifferentiation. Recognition of this variant of central low-grade osteosarcoma is based on the aggressive radiologic appearance and on adequate tumor sampling for histologic examination.
中央型低度骨肉瘤是骨肉瘤的一种罕见形式，常难以与良性骨病变相鉴别。我们回顾了两名中央型低度骨肉瘤患者的影像学检查、组织学材料及临床记录，这两名患者的组织学表现与骨Paget病极为相似。患者为两名女性，年龄分别为46岁和53岁。影像学上，她们均表现为累及胫骨近端的边界不清的大片致密硬化性病变。两处病变仅局部呈现中央型低度骨肉瘤的传统组织学表现，有成纤维细胞样细胞增生，包埋于致密的胶原性基质中，并见不规则相互吻合的肿瘤骨小梁。最显著的特征是存在极厚的不规则骨板，其骨水泥线呈不规则镶嵌样图案，与骨Paget病极为相似。其中一名患者最初因骨Paget病接受治疗7年，病情进展。在切除胫骨近端时，有证据表明已去分化为高级别骨肉瘤。2个月后，她出现局部复发，接受了膝上截肢术，随后进行化疗。4个月后，她死于多发肺转移。另一名患者在广泛切除肿瘤9个月后仍存活。这些病例进一步拓展了中央型低度骨肉瘤的范畴，并强调了将中央型低度骨肉瘤与良性骨疾病相鉴别时的诊断困难，这可能导致诊断延迟、治疗不足，并最终发生去分化。对中央型低度骨肉瘤这一变异型的认识基于其侵袭性的影像学表现及足够的肿瘤组织取样以进行组织学检查。
