Extraenteric Malignant Gastrointestinal Neuroectodermal Tumor of the Neck: A Diagnostic Challenge

Malignant gastrointestinal neuroectodermal tumor (MGNET) and clear cell sarcoma (CCS) of soft tissue represent related, extremely rare, malignant mesenchymal neoplasms. Both entities are genetically characterized by the same molecular alterations, EWSR1::CREB1 fusions. Malignant gastrointestinal neuroectodermal tumor has significant morphological overlap with CCS, although it tends to lack overt features of melanocytic differentiation. Recently, rare MGNET cases were reported in extragastrointestinal sites. The diagnosis represents a major challenge and significantly impacts therapeutic planning. In this study, we reported the clinicopathologic features of a molecularly confirmed MGNET of the neck and provided a review of the pertinent literature.