Congenital Primitive Neuroectodermal Tumor (PNET) of the Orbit

Purpose: To report a case of the congenital primitive neuroectodermal tumor (PNET) of the orbit. Case Report: The patient was a 2-week-old neonate referred to the oculoplastic clinic with right eye proptosis from birth. The neonate was a full term with a history of difficult vaginal delivery. At an initial examination, the ecchymosis of the medial right upper lid was noted. At an initial CT scan, an isodense intraconal infiltrative mass without distinct margins and without bone erosion or calcification was present. With an initial diagnosis of retrobulbar hemorrhage due to a difficult delivery, the patient was followed. With regard to the progressive course of proptosis in the follow-up period, orbitotomy and incisional biopsy were performed and after histologic evaluation, the primitive neuroectodermal tumor was diagnosed. The patient was treated with combination adjuvant chemotherapy regimen. After 5 cycles of chemotherapy, proptosis significantly improved. One year after disease diagnosis, there was no symptom or sign of recurrence. Conclusion: In congenital masses or proptoses, the possibility of PNET should be considered, although it is not common.