原发于非骨组织的骨肉瘤称为骨外骨肉瘤,可发生在身体任何部位,在临床上很少见,约占骨肉瘤的3.6%,而原发于乳腺的骨肉瘤则更为罕见。现将1例报告如下。1病例介绍患者女性,46岁,因“发现右乳肿块5月余明显增大3天”入院。查体:右乳外上象限距乳头3 cm处扪及一大小约5cm×5 cm×4 cm肿块,质硬,边界清楚,可推动,无压痛,无局部 Primary osteosarcoma in non-bone tissue called osteosarcoma, can occur in any part of the body, is clinically rare, accounting for about 3.6% of osteosarcoma, and primary osteosarcoma in the breast is even more rare. Now one report is as follows. 1 case description Female patients, 46 years old, because “found right breast enlargement in May more than 3 days ” admission. Physical examination: the right upper quadrant of the right breast away from the nipple 3 cm at a palpable size of about 5cm × 5cm × 4cm mass, hard, clear boundary, can promote, no tenderness, no local