**Author details**

Taghi Azizi\*

c)

recent study has identified a novel *HEY1-NCOA2* fusion in MCS which appears to be a

a) b)

**Figure 29.** a) High-grade chondrosarcoma b) with marked S100 PROTEN increase in cellularity and myxoid matrix

Positive: FLI1 (nuclear), CD99, vimentin; rarely keratin. May react with other neural markers

a) b)

**Figure 30.** a) Small nucleoli scant cytoplasm with mitosis b) diffuse strong membranous expression of CD99

High-grade, primitive neuroectodermal neoplasm (Figure 30)

(NSE, synaptophysin, S100 protein, NFP, GFAP, chromogranin). [72-79]

consistent finding. [70, 71]

330 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

**6.3. Ewing sarcoma**

*6.3.2. Immunohistochemical stains*

*6.3.1. Definition*

Address all correspondence to: aziziarshia@yahoo.com

Department of Oral and Maxillofacial Pathology, Baqiyatallah University of Medical Sciences Tehran, Iran
