[Clinicopathological study of Ewing's sarcoma/primitive neuroectodermal tumor in oral and maxillofacial region].
OBJECTIVE
To study the clinicopathological features and diagnostic criteria of Ewing's sarcoma/primitive neuroectodermal tumor (Ewing's sarcoma/PNET) in oral and maxillofacial region.


METHODS
There were 15 patients with Ewing's sarcoma/PNET in the last 35 years at our hospital, aged 1-49 years and mean 14.5 years. The most common manifestation was swelling of the affected region. The cases were analyzed and histological and immunohistochemical studies were also conducted to examine CD99 (12E7), Vimentin, NSE, S-100, Syn, CD45 (LCA), desmin.


RESULTS
(1) The most common histological pattern of Ewing's sarcoma/PNET was a lobular arrangement of uniform, small, hyperchromatic cells in a fibrous background. Some of these tumors were rich in cytoplasmic glycogen. (2) Of the 7 cases, IHC was positive for CD99 (12E7) and Vimentin and negative for lymphoid (CD45), muscle (desmin) markers. S-100 was positive in 4 cases and NSE negative in 3, Syn positive in 1. NSE, S-100, Syn were all negative in 2 cases.


CONCLUSIONS
Ewing's sarcoma/PNET is more common in teenagers and young people. Immunohistochemistry is essential to distinguish Ewing's sarcoma/PNET from other small round cell tumors. Immunohistochemistry is useful in the diagnosis.
He
Hua-wei
HW
Department of Pathology, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Liu
Lai-kui
LK
Li
Yi-ning
YN
Wang
Dan
D
He
Zhi-xiu
ZX
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005153:Facial Neoplasms / Q000175:diagnosis / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007573:Jaw Neoplasms / Q000175:diagnosis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000175:diagnosis / Q000473:pathology*; D012512:Sarcoma, Ewing / Q000175:diagnosis / Q000473:pathology*; D055815:Young Adult