Milchgrub S, Ghandur-Mnaymneh L, Dorfman H D, Albores-Saavedra J
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235-9072.
Am J Surg Pathol. 1993 Apr;17(4):357-63. doi: 10.1097/00000478-199304000-00006.
Four cases of synovial sarcoma with extensive calcification and osteoid and bone formation are reported. Ages ranged from 21 to 38 years. Two tumors were located in the foot and two in the thigh. Because of a well-circumscribed, densely calcified soft tissue mass, radiologically three patients were thought to have a benign lesion. The fourth patient was thought to have a paraosteal osteosarcoma because of an accompanying bone defect. Tumor size varied from 4.0 to 9.0 cm. Histologically, three tumors were biphasic and one predominantly monophasic. All showed amorphous calcifications with extensive ossification sometimes in a ribbon-like pattern of osteoid, simulating osteosarcoma. The extensive bone formation with abundant osteoid deposition may lead to a misdiagnosis of osteosarcoma. It is important to recognize this variant of synovial sarcoma with ossification and bone formation and distinguish it from extraskeletal osteosarcoma because of the difference in clinical behavior and course. Although the most important point in the recognition of this variant of synovial sarcoma is its biphasic pattern, this may not be apparent in a small tissue sample. Points that aid in the diagnosis include the uniform nuclear appearance of both the epithelial and the spindle cells versus the pleomorphism of osteosarcoma and in some cases the presence of amorphous concretions in sheets and small calcospherites within spaces surrounded by flat or conspicuous epithelial cells. These cells are immunoreactive for cytokeratin and epithelial membrane antigen.
报告了4例伴有广泛钙化及骨样和骨形成的滑膜肉瘤。年龄范围为21至38岁。2例肿瘤位于足部，2例位于大腿。由于存在边界清楚、高密度钙化的软组织肿块，3例患者在放射学上被认为患有良性病变。第4例患者因伴有骨缺损而被认为患有骨旁骨肉瘤。肿瘤大小从4.0厘米至9.0厘米不等。组织学上，3例肿瘤为双相性，1例主要为单相性。所有病例均显示无定形钙化伴广泛骨化，有时呈带状骨样结构，类似骨肉瘤。广泛的骨形成伴大量骨样沉积可能导致骨肉瘤的误诊。认识到这种伴有骨化和骨形成的滑膜肉瘤变体并将其与骨外骨肉瘤区分开来很重要，因为两者临床行为和病程有所不同。虽然识别这种滑膜肉瘤变体的最重要点是其双相模式，但在小组织样本中可能并不明显。有助于诊断的要点包括上皮细胞和梭形细胞核外观一致，与骨肉瘤的多形性不同，以及在某些情况下，在由扁平或明显上皮细胞围绕的间隙内存在成片的无定形凝结物和小钙化球。这些细胞对细胞角蛋白和上皮膜抗原呈免疫反应性。
