Reference ID: THY-T-7
History: A 40 y/o white female presented with a diffuse thyroid enlargement.
She also sufferes from hypothyroidism.

Diagnosis: Hashimoto Thyroiditis (HT) aka Chronic Lymphocytic Thyroiditis
Discussion:
The cytodiagnosis of HT consists simply of lymphocytes and oncocytes (hurthle cells), in variable proportions. Lymphocytes infiltrating clusters of hurthle cells, ie, lymphocytes intemately associated with hurthle cells, are particularly characteristics of HT. The lymphocytes can be found in various stages of maturations. The morphology of hurthle cells is variable, but the cells can be pleomorphic, with abnormal nuclei, including enlarged, dark, or pyknotic forms, irregular nuclear membranes, and prominent nucleoli, although macronucleoli are unusual. Ordinary follicular epithelium is usually also present.

References:
Demay 2nd edition page, 872 to 875
Atkinsons page 463.