Pathologic characteristics of primary primitive neuroectodermal tumor in the cervix: a small round cell malignant tumor with glial and epithelial differentiation after neoadjuvant chemotherapy.

Primary primitive neuroectodermal tumor (PNET) of the cervix is extremely rare. Only few previous researches have reported on morphologic descriptions in frozen sections or changes in this tumor after radiotherapy or chemotherapy treatments. In the following study we investigated two cases of PNET in cervix. One of which had taken frozen exam and the other experienced neoadjuvant chemotherapy. Briefly, the morphological analysis in intraoperative frozen indicated small round cell malignant tumor with Homer-Wright rosettes, which similar to that in paraffin sections. The morphological changes after chemotherapy showed glial and epithelial differentiation as well as other common reaction. Immunochemistry test of neural and neuroendocrine markers and the detection of EWSR1 gene rearrangement may show positive in this disease in cervix. In conclusion, the obtained data may be useful for further examination, detection and diagnosis of PNET in clinical practice. Also, to the best of our knowledge, this was the first time that morphological and pathological changes were examined in PNET post-chemotherapy. However, the exact mechanisms of these changes require further exploration.