Prenatal Diagnosis of a Melanotic Neuroectodermal Tumor of Infancy (MNTI): A Case Report with a Favorable Outcome after Chemotherapy Failure and Incomplete Resection

We present the case of a woman referred to our department at 34 weeks of pregnancy with a fetal ultrasonographic scan showing a mass that had developed within the right maxilla with invasion of the orbit. A retrospective examination showed that this tumor had been present since the 12th week of pregnancy. At 39+4 weeks of gestation, a boy was born. He presented a black firm aspect in the maxilla. A computed tomographic scan and magnetic resonance imaging revealed a soft tissue swelling over the right maxilla, extending into the orbit but without invasion of the globe. Surgical biopsy confirmed a melanotic neuroectodermal tumor of infancy. The pathologic examination did not show any neuroblast-like component on the hematoxylin eosin saffron staining. Because of the extension and the size of the lesion, neoadjuvant chemotherapy was carried out. At day 21, the patient received 1 cycle of low-dose cyclophosphamide and vincristine, 2 cycles of etoposide and carboplatin, and thereafter 1 cycle of cyclophosphamide, adriamycin, and vincristin because the lesion kept growing. After stabilization of the size of the tumor, at 4 months, a maxillectomy and partial resection of the orbital floor and lateral orbital wall was performed on the patient. As a complete resection would have required orbital exenteration, surgery was performed deliberately incomplete leaving a macroscopic residue (R2). At 2.5 years of follow-up, the patient showed complete remission with no lesions evident on magnetic resonance imaging.