Problematic Differential Diagnoses in Paranasal Sinus Tumor Histopathology

Purpose of Review: The sinonasal tract (paranasal sinuses and nasal cavity) is a particularly challenging anatomic subsite for surgical pathologists to evaluate. The stakes for the patient are high, because radically different treatment decisions are entirely dependent on a precise histopathologic diagnosis. Unfortunately, pitfalls abound in dealing with these neoplasms. Recent Findings: This manuscript serves as an updated review of three specific differential diagnoses for tumors encountered in the sinonasal tract: the glandular proliferation, the inverted squamous neoplasm, and the small round blue cell tumor. Summary: An awareness of these challenging differential diagnoses coupled with a careful diagnostic approach will allow pathologists to arrive at the correct diagnosis.