CALCIFYING SOLITARY BONE-CYST - MORPHOLOGICAL ASPECTS AND DIFFERENTIAL-DIAGNOSIS OF SCLEROTIC BONE-TUMORS

Fourteen solitary bone cysts (SEC) with large areas of calcification ( 7 in the femur, 4 in the humerus, and 1 each in the pelvis, the tibia and the scapula) and 402 SEC from the Hamburg Bone Tumour Registry wer e reviewed in a retrospective study. The analysis was done with emphas is on the clinical, radiological and histological appearances. SEC are well known lesions, but calcifying SEC (CSBC) or extensive extragnath ic cement-like bone productions are rare. The clinical and radiologica l differential diagnosis includes fibrous dysplasia, chondroma, low-gr ade chondrosarcoma and osteosarcoma. Bits of this cement-like matrix a re detectable within the wall of approximately 70% (278 of 402) of SEC from the registry. CSBC are changed SEC. The intraoperative confirmat ion of the diagnosis on a frozen section by the bone pathologist leads to curettage which is currently the most common therapy in this benig n lesion.