A rare case of deep lobe parotid pleomorphic adenoma featuring parapharyngeal extension: Clinical, radiological and surgical implications: A case study

Background: Tumors arising from the deep lobe of the parotid gland with extension into the parapharyngeal space (PPS) are rare and often present without an external cervical mass. This atypical presentation may delay diagnosis and complicate surgical management. Pleomorphic adenoma, although the most common benign salivary gland tumor, infrequently involves the deep lobe with parapharyngeal extension.
Case Presentation: A 52-year-old woman presented with a 7-month history of progressive oropharyngeal fullness and mild dysphagia, without neck swelling or facial nerve dysfunction. Clinical examination revealed a bulge of the right lateral pharyngeal wall. High-resolution magnetic resonance imaging demonstrated a well-defined, encapsulated mass measuring approximately 45 × 55 × 39 mm arising from the deep lobe of the right parotid gland and extending into the prestyloid parapharyngeal space. Intraoral fine-needle aspiration cytology suggested a salivary gland neoplasm of uncertain malignant potential (Milan System). Complete surgical excision was achieved using a combined transcervical–intraoral approach without mandibulotomy. Facial nerve integrity was preserved with intraoperative nerve monitoring. Histopathological analysis confirmed pleomorphic adenoma.
Conclusion: Deep lobe parotid pleomorphic adenomas with parapharyngeal extension require a high index of suspicion due to their subtle clinical presentation. Careful preoperative imaging and cytological assessment are essential for accurate diagnosis and optimal surgical planning. The combined transcervical–intraoral approach represents a safe and effective option, offering excellent oncological control while preserving facial nerve function and minimizing surgical morbidity.