Clear but Not Simple: Diagnostic Challenges of a Rare Case of Hyalinising Clear Cell Carcinoma of the Palate

Hyalinising clear cell carcinoma is an uncommon neoplasm arising in minor salivary glands. It is a rare low-grade malignant tumour composed of clear cytoplasmic cells. This case report outlines the presentation of a 36-year-old female with a history of growth in the palatal region for six months. Examination revealed a mass originating from the left hard palatal region, and on correlation with radiographic examination, biopsy was advised. Pathological examination revealed typical clear cells arranged in anastomosing trabeculae, cords, nests, or solid sheets with hyalinising stroma. These cells were strongly positive for periodic acid-Schiff (PAS) but were negative for mucicarmine. Immunohistochemically, these neoplastic cells were immunoreactive to cytokeratin 8/18 but negative to smooth muscle actin, which aids in the diagnosis. Left subtotal maxillectomy was done for the excision of the tumour, followed by radiotherapy, along with follow-up of 18 months without recurrence.