Sinonasal undifferentiated carcinoma in a patient previously treated for an intestinal-type adenocarcinoma: metachronous neoplasms or recurrence of a different tumor type?
A case of a sinonasal undifferentiated carcinoma occurring 2 years after a successfully surgically treated intestinal-type adenocarcinoma has never been reported. Treatment modality of paranasal sinus cancer strictly depends on histology so it is important to recognize a different tumor type in the follow-up of these patients