Giant Parapharyngeal Space Pleomorphic Adenoma of the Deep Lobe of Parotid Presenting as Obstructive Sleep Apnoea: A Case Report & Review of the Diagnostic and Therapeutic Approaches

Abstract

Introduction: Salivary gland tumours constitute about less than 4 % of all head and neck tumours. Pleomorphic adenoma, also called benign mixed tumour, is the most common tumour of the salivary glands. About 80-90 % of these tumours occur in the major salivary gland mainly parotid gland and 10 % of them occur in the minor salivary glands.

Aims and methods: Aim of this case report is to discuss the unique case of giant parotid pleomorphic adenomas arising in the deep lobe involving the parapharyngeal space and difficulty in respiration at sleep during nights repoted at this institute. The patient was undergoing treatment for obstructive sleep apnea syndrome when she reported at this institute for disturbed sleep. Diagnosis was based on computed tomography scan and magnetic resonance imaging and cytology by means of fine needle aspiration biopsy.

Conclusion: An exhaustive pre-operative diagnostic algorithm is mandatory before approaching such lesions involving parapharyngeal space. Fine needle aspiration biopsy is, in our opinion, mandatory to avoid histological surprises. The surgical approach varies according to the location of the tumour and should provide excellent visibility with wide surgical exposure to secure local neurovascular structures.

Keywords: Deep lobe pleomorphic adenoma; Mandibular swing; Obstructive sleep apnea; Tran cervical approach.

Fig. 1

MRI Showing axial section

Fig. 2

MRI showing sagittal section

Fig. 3

Showing transcervical approach with osteotomy prepared for mandibular swing

Fig. 4

Showing tumour mass after mandibular swing

Fig. 5

Showing fixation of osteotomy by miniplates

Fig. 6

Showing excised specimen of 54 x 65 x 35 mm size