Hyalinizing clear cell carcinoma in minor salivary glands of maxillary tuberosity

Hyalinizing clear cell carcinoma (HCCC) is a newly described entity with distinctive histological features. A 48-year-old woman with HCCC was described in minor salivary glands of right maxillary tuberosity with two years duration. Physical examination revealed a red-colored, firm mass measuring 2.0 cm × 1.8 cm with telangiectases in the overlying mucosal surface. Computed tomography scans demonstrated a bony destruction of buccal cortex of maxillary alveoli and right maxillary tuberosity. Resection biopsy, wide excision of the underlying alveoli including part of maxilla was performed. Pathological examination revealed typical clear cells arranged in anastomosing trabeculae, cords, nests, or solid sheets with a hyalinizing stroma. These clear cells were strongly positive for the periodic acid-Schiff (PAS) but were negative for the mucicarmine staining. Immunohistochemically, those neoplastic cells were immunoreactive to cytokeratin, but negative to smooth muscle actin and S-100 protein. Neither recurrence nor distant metastasis was found during the 12-month follow-up period.