Objective:To examine clinical and pathological features of adult nosal embryonal rhabdomyosarcoma and to investigate the effective diagnosis and prognosis.Methods:The adult nasal ERMS specimens collected by the Pathology Department of Yichang Central People’s Hospital were analyzed.For both patients

representative hematoxylin and eosin-stained slides of tumors were available for review.Immunohistochemical stains(SP method) were performed on a selected paraffin block.And the information of clinical diagnosis and treatment was reviewed.Results:The 2 cases were male.ERMS was characterized by an admixture of undifferentiated

small

round or spindle cells which were rich in chromatin and were separated into patchy form or mass by scanty fibrous septa.The nuclear chromatin was thick with eosinophilic cytoplasm.Immunohistochemically

the tumor cells were positive for MyoD1

myogenin

myoglobin

Actin(Sarcomeric)

Actin(pan)

desmin and Vimentin

but negative for Cytokeratin(pan)

Epithelial Membrane Antigen(EMA)

CD45(LCA)

Actin(Smooth Muscle)

S-100 Protein

Melanoma(HMB-45)

CD34

Neuron Specific Endolase(NSE)and CD99.Conclusion:Adult nasal ERMS has no specific clinical features

so it’s often misdiagnosed.CT is an important method to provide us with important clues to the diagnosis of ERMS

and its final diagnosis mainly depends on histopathological and immunohistochemical findings.Early diagnosis and surgery combined with radiotherapy and chemotherapy are effective treatment for adult nasal ERMS.