An Unusual Clinical Morphology of Bilateral Pleomorphic Adenoma with Unilateral Cystic Degeneration; a Consequence of Delay in Consent for Treatment: A Case Report

Background: Pleomorphic adenoma is the most common benign tumour of the salivary glands with majority found in the parotid gland. It accounts for 3% of all head and neck tumours and 70-80% of benign salivary gland tumours. The clinical features depend on the size, location and in some cases the potential to undergo malignant transformation. They are usually solitary, unilateral, firm and mobile, painless and slow growing, hence the long duration before presentation for treatment. Purpose: To present an 84-year-old female who first presented 16 years ago with a 4-year history of bilateral swellings at the left and right parotid regions, measuring 8.0 cm by 10.0 cm and 3.0 cm by 5.0 cm respectively. Due to fear of surgery, the patient gave consent for the excision of only the left lesion whose histology report came out to be pleomorphic adenoma. The right swelling was left in-situ. The time lapse of 16years resulted in gradual increase in size of the right lesion now measuring 12.0 cm by 8.0 cm with no clinical symptoms but aesthetically unpleasant to patient. With consent, the right lesion was excised and pathological examination showed a benign lesion composed of ovoid and spindle-shaped epithelial cells arranged in sheets and ducts, some of which contain eosinophilia coagulum and cystic degeneration in other foci. No evidence of malignancy. No post-operative recurrence on the left side16 years after and on the right side 24 months after treatment Conclusion: Pleomorphic adenoma can grow to enormous size, and with a potential to undergo cystic degeneration if left untreated. Early presentation for treatment is of high importance to prevent complications associated with delay.