Hyalinizing clear cell carcinoma

Signs and symptoms

HCCCs typically present as a painless mass in the mouth.

Diagnosis

HCCCs are diagnosed by examination of tissue, e.g. a biopsy.

Pathology

HCCC consist of cells with abundant clear cytoplasm, arranged in cords, trabeculae or clusters in a hyalinized stroma. Nuclear pleomorphism is usually minimal and mitoses are infrequently seen.

Owing to their glycogen content, which explains the "clear" appearance under the microscope, tumour cells stain with PAS. Immunostains for S100 and smooth muscle actin (SMA) are typically negative, but positive for cytokeratins and epithelial membrane antigen (EMA).

HCCCs typically have a recurrent chromosomal translocation, t(12;22), involving the genes EWSR1 and ATF1. The same translocation is seen in clear cell sarcoma.

The histologic differential diagnosis includes mucoepidermoid carcinoma (clear cell variant), acinic cell carcinoma (clear cell variant), epithelial-myoepithelial carcinoma and metastatic clear cell carcinoma. Image: Hyalinizing clear cell carcinoma - intermed mag.jpg | Intermed. mag. Image: Hyalinizing clear cell carcinoma - very high mag.jpg | Very high mag.

Prognosis

They generally have a good prognosis.

References

References

1. (July 2011). "Hyalinizing clear cell carcinoma: a case report and review of the literature". Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontics.
2. (January 1994). "Hyalinizing clear cell carcinoma of salivary gland". The American Journal of Surgical Pathology.
3. (September 2009). "Hyalinizing clear cell carcinoma: report of eight cases and a review of literature". Head and Neck Pathology.
4. (July 2011). "EWSR1-ATF1 fusion is a novel and consistent finding in hyalinizing clear-cell carcinoma of salivary gland". Genes, Chromosomes & Cancer.
5. (2011). "Hyalinizing clear cell carcinoma of the base of tongue: a distinct and rare entity". Indian Journal of Pathology & Microbiology.