Preoperative cytodiagnosis of cystic pleomorphic adenoma with squamous metaplasia and cholesterol crystals: A case report

Background: Pleomorphic adenoma with extensive squamous metaplasia and cystic change may cause diagnostic confusion both in cytology and histopathology, which stresses the need for a guarded approach while interpreting such lesions. Case: A 50-year-old man presented with a submandibular swelling of 6 months' duration. Routine fine needle aspiration (FNA) yielded mucoid fluid, mixed with whitish particles. Cytologic smears revealed fibromyxoid connective tissue fragments, epithelial cell clusters exhibiting squamous metaplasia, clumps of keratin material, few multinucleated giant cells, a large number of cholesterol crystals and scattered cyst macrophages in a thin proteinaceous background. The cystic nature of the swelling caused some degree of diagnostic dilemma; however, ultimately, a cytologic diagnosis of "pleomorphic adenoma with squamous metaplasia and cystic change" was offered, which was confirmed by subsequent histopathologic examination. Conclusion: Our case emphasizes the need for a cautious and systematic approach in the cytologic and histopathologic interpretation of cystic pleomorphic adenoma with metaplastic epithelial changes. Cholesterol crystals found in the aspirate material of our case is a rare finding in pleomorphic adenoma.