Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid

Abstract

Sclerosing mucoepidermoid carcinoma of the thyroid was first reported in 1991. This tumour type may develop as associated to Hashimoto thyroiditis. There are two variants of mucoepidermoid carcinoma of thyroid. The conventional and the sclerosing variants. Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid (SCME) has recently been recognised as a separate disease entity by the WHO. We report a case of SCME in a 62-year-old male patient who presented with a painless anterior neck swelling. Total thyroidectomy was performed, and no adjuvant treatment administered. The patient remained disease free up until 10 months of follow-up. Approximately 40 cases are reported in literature. We report the second case of SCME in Asian men. Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid should be differentiated from the conventional mucoepidermoid carcinoma. Patients should also be advised of long-term follow-up for surveillance.

Keywords: ear, nose and throat/otolaryngology; thyroid disease.

Figure 1

(A) Tumour exhibiting combination of squamoid cells (large arrow), intermediate cells (small arrows) and cystic spaces (stars). (H&E stain, 200×). (B) Cystic spaces lined by mucinous cells (arrows) (H&E stain, 200×). (C) Small nests of tumour cells (small arrows) were seen against sclerotic background stroma. A lymphoid follicle was also seen (large arrow) (H&E stain, 100×). (D) Intervening stroma between tumour cells showed eosinophil rich inflammatory infiltrate (H&E stain, 400×).

Figure 2

Tumour cells exhibited cytoplasmic and membranous staining for (A) cytokeratin 5/6 and nuclear staining for (B) TTF-1 immunohistochemical stains. (C) Periodic acid-Schiff-alcian Blue special stain highlights intraluminal and intracytoplasmic mucin.

Figure 3

(A) Interface of tumour nests (arrows) with adjacent thyroid tissue (H&E stain, 200×). (B) Adjacent thyroid tissue exhibited prominent Hurthle cell change (large arrow) and lymphoid aggregate (short arrow) (H&E stain, 400×).