MUC5AC and neoplasm: Tumours comprised relatively small, polygonal epithelial cells with round nuclei, indistinct nucleoli, and eosinophilic or clear cytoplasm. Tumour cells formed an astomosing cords or solid nests with highly irregular borders in a fibrotic-to-hyalinised background. Glandular structures with mucin production confirmed with mucicarmine stain. No keratinization, tumor necrosis was observed