Unusual presentation of nasal pleomorphic adenoma masquerading as malignancy: A rare case report

Pleomorphic adenomas (PA) is the most common benign salivary gland tumor, typically arising in major glands like the parotid. The occurrence of PA in the nasal cavity is rare; however, when present, it most commonly originates from the nasal septum. Intranasal PAs may resemble malignancies due to their atypical features, posing diagnostic challenges. Accurate diagnosis is essential to avoid unnecessary aggressive treatment. We report the case of a 71-year-old female patient, who consulted our ENT department for unilateral nasal obstruction. CT scan revealed a near-complete obstruction of the right nasal cavity by a tissue mass causing erosion of the medial wall of the maxillary sinus. Initial biopsy pathology suggested squamous cell carcinoma (SCC). The patient underwent surgical resection, and the final histopathological diagnosis was pleomorphic adenoma. The disease typically presents as a slow-growing unilateral nasal obstruction, that may extend to cause severe deformation or necrosis in advanced cases. Histologically, intranasal PA differs from their major salivary gland counterparts by exhibiting higher cellularity and reduced stromal component, features that may resemble malignant tumors. Diagnosis is achieved through complete surgical excision followed by thorough histopathological evaluation of the entire specimen. Treatment relies on complete excision with clear margins. Pleomorphic adenomas of the nasal cavity are rare and may mimic malignancy due to their atypical morphology making accurate diagnosis essential to avoid overtreatment. Despite their benign nature, long-term follow-up is essential given the potential for recurrence and malignant transformation. • Pleomorphic adenomas (PAs) are the most common benign tumors of the salivary glands, but are rarely encountered in the nasal cavity. • Definitive diagnosis requires complete surgical excision and histopathological evaluation of the entire specimen. • Histologically, intranasal PAs often exhibit increased cellularity and a reduced stromal component compared to those in major salivary glands, potentially mimicking aggressive epithelial malignancies and leading to diagnostic challenges. • Complete surgical excision with clear margins remains the gold standard for the treatment of pleomorphic adenoma. • Malignant transformation is rare; however, recurrence may occur in cases of incomplete resection or intraoperative tumor spillage.