Pathology Quiz Case

A 75-YEAR-OLD MAN PRESENTED WITH A 2-month history of progressive rightsided nasal obstruction and bleeding. He had received antibiotic treatments, without significant improvement. His nose bleeds had continued even though he had stopped taking antiplatelet medications. He had no known history of paranasal sinus disease. His medical history was remarkable for arterial hypertension and coronary artery disease. He had undergone a coronary artery bypass grafting procedure 1 year before presentation. Fiberoptic examination of the nasal cavity revealed a polypoid mass filling the entire nose on the right side, with some minimal amount of recent bleeding. The findings of a comprehensive head and neck examination were otherwise normal. A recent computed tomogram showed opacification of the right nasal fossa as well as the maxillary, ethmoidal, and frontal sinuses. The patient underwent an endoscopic biopsy and debulking for pathologic diagnosis. A lesion was observed extending from the olfactory cleft, attached to the anterior skull base, with involvement of the nasal septum. The maxillary, ethmoidal, and frontal sinuses demonstrated retention disease. The frozen section obtained during surgery showed a neoplastic process (Figure 1). The final surgical treatment was deferred until a more definite pathologic diagnosis could be made. Immunostains were negative for widespectrum cytokeratin, keratins AE1 and AE3, Cam 5.2, S-100 protein, p63, caldesmon, and synaptophysin. While it was clear that the tumor was destructive and probably malignant, no definitive diagnosis was made. A limited anterior skull base resection was performed, and the margins were cleared during surgery. The tumor was confined to the right olfactory cleft and extended to the superior nasal septum, without intracranial involvement. The specimen consisted of several bony fragments, representing the entire right anterior skull base, from the planum sphenoidale to the posterior wall of the right frontal sinus. Microscopic examination of the tissue resected from the second procedure showed a highgrade malignant neoplasm with anaplastic tumor cells and foci of calcification (Figure 2 and Figure 3). What is your diagnosis? Figure 1.