A Rare Case of Pleomorphic Adenoma of the Nasal Cavity with Extensive Squamous Metaplasia: A Diagnostic Pitfall

Abstract

Pleomorphic adenoma (PA) is one of the most common benign tumor of the major salivary glands. Its occurrence in the nasal cavity, particularly arising from minor salivary glands of the nasal septum, is rare. Due to its unusual location and diverse histomorphology, it is often associated with diagnostic challenges. We report a case of a 56-year-old female presenting with unilateral nasal obstruction of 3 months duration on the right side of the nose. Radiological evaluation revealed a well-defined lesion in the right nasal cavity arising from the anterior nasal septum without evidence of bone destruction. Histopathological examination established the diagnosis of PA with extensive squamous metaplasia and keratin pearl formation, imparting a morphology that closely mimics keratinizing lesions of the nasal cavity. In conclusion, PAs in the nasal cavity are uncommon and often show higher epithelial cellularity with reduced stromal components compared to their major salivary gland counterparts, which may lead to misdiagnosis, particularly in limited biopsy specimens. Recognition of such histological variations is essential to avoid overdiagnosis and aggressive treatment.