Thyroid: Hashimoto’s Thyroiditis  

Case 1 42 year old woman, nodular left lobe of thyroid, lobectomy following non-diagnostic cytology. Hashimoto’s Thyroiditis with Lymphoepithelial Cysts (Cystic Variant of Hashimoto’s). This case showed some typical background Hashimoto like changes but it also showed a multicystic appearance with a fibrous and lymphoid stroma with the cysts containing proteinaceous fluid and cholesterol clefts. The epithelium lining the cysts was flattened and bland without atypia. The features indicated Hashimoto’s thyroiditis with squamous metaplasia and lymphoepithelial cysts. There was a wide range of differential diagnoses; intrathyroidal lymph node with epithelial inclusions, Hashimotos’ with squamous metaplasia, Ectopic thymoma, lymphoepithelial cysts and thymic tissue. 

References

1. Cystic Variant of Hashimotos thyroiditis in Lloyd RV et al in AFIP Atlas of Non-Tumor Pathology: Endocrine Diseases, 2002 page 123 or Carter E, Ulusarac O.

2. Lymphoepithelial Cysts of the Thyroid Gland, Arch Pathol Lab Med 2003:127:205-08