This is from a 60 year old woman who died of a drug overdose. At autopsy her thyroid was a little small but pale and firm. On histology, there is a prominent lymphocytic thyroiditis. Within the areas of inflammation are enlarged eosiniphilic cells, called Hurthle cells.
Here is a low power view. The darker blue areas are aggregates of lymphocytes.
Here are medium power views. You can see within the collections of lymphocytes there are clumps of pink cells. You can see the smaller normal follicular epithelial cells at the edge of the images.
And a high power view:
Hurthle cells are big and eosinophilic because they are filled with mitochondria. They are characteristic of Hashimoto’s thyroiditis, but can arise as independent benign and malignant neoplasms.
You’ll note that I called this a “lymphocytic thyroiditis” rather than “Hashimoto’s thyroiditis” because I was trained that you couldn’t call it Hashimoto’s unless you saw Hurthle cells *and* germinal centers, and I didn’t see any good germinal centers in this slide.
As always, free for use in lectures, etc. with or without attribution — though attribution is appreciated. If you need a higher resolution image, contact me.