恶性肿瘤，首先考虑颌骨成骨肉瘤。基于部位，确实需要结合免疫组织化学检测数据除外上皮源性肿瘤，尤其是小涎腺肿瘤。

显示的成份主要呈血管外皮瘤的结构，但远离血管一侧的肿瘤细胞之间有粉红基质形成。

应该注意的是，如果是成骨肉瘤，这样细胞较小的病变恶性程度较高，这在颌骨成骨肉瘤中不多见。

如果系切除标本，应多取材，寻找更典型的成骨及成软骨区域，能确定诊断。

又采了几幅图，局部似乎有软骨化生。

这样的部位，这种形态，这种表型，如果能够真正除外上皮性肿瘤，尤其是肌上皮性肿瘤，就应该把成颌骨成骨肉瘤以及间叶性软骨肉瘤放在前面。

 I have to apologize for wrting in English. My Chinese typing is very poor. I had a look at the photos and also showed them to couple of colleagues here in Univeristy of Rochester. The tumor border seems demarcated, even though could be multi lobulated. Tumor cells are bland and generally uniform, no pleomorphism, necrosis, and active mitosis seen. There seems to be matrix formation, including some cartillage, and seems rich in vasculature, at least focally, with perivascular condensation of tumor cells. My general impression is: this is probably a benign tumor, or, to the worst, with very low grade malignancy. My differential diagnosis includes: pleomorphic adenoma (mixed tumor), glomus tumor, PICOma, and myoepithelioma. It is difficult to be certain at this time without any positive immuno stain to support one way or the other. But I don't think it is osteosarcoma, mesenchymal chodrosarcoma or other small round blue cell tumors. What kind of bone damage he has? Is it infiltrative or erosive? Benign tumor can cause bone damage by putting pressure on it. Overall, it seems to me that this is a tumor in the soft tissue, and is most likely benign to very low grade malignancy. I am looking forward to seeing the excision specimen.