Pleomorphic adenoma of the maxillary sinus with orbital extension presenting with exophthalmos: a case report.

We report a case of pleomorphic adenoma (PA) of the maxillary sinus, an unusual and rare location of this frequent benign neoplasm originating from salivary glands and accounting for 70% of all salivary gland tumors, presenting with compressive phenomena from the orbit and the challenges in its differential diagnosis and management. A 66-year-old male presented with progressively worsening exophthalmos over the past 4 months and symptoms of nasal obstruction on the left side for the past year. Clinical evaluation and imaging studies revealed complete occupation of the left maxillary sinus by a mass with soft tissue characteristics, extending to the homonymous nasal cavity and orbit. Functional endoscopic sinus surgery (FESS) was performed. The surgical plan included septoplasty and medial maxillectomy and complete resection of the tumor with clear margins. The histopathology report was consistent with a PA of the maxillary sinus. PA of the maxillary sinus is an extremely rare disease entity. Orbital involvement due to extension of an undiagnosed PA as described in this case is very uncommon. Thorough investigation is required in cases of unilateral nasal obstruction. Complete surgical excision and close long-term follow-up are required due to the probability of tumor recurrence and potential malignant transformation.