Hashimotoâ€™s disease (autoimmune thyroiditis)
Organspecific autoimmune disease causing thyroiditis and later hypothyroidism.
Peak in middle age.
F > M (10:1)
Patients have detectable antimicrosomal antibody and antithyroglobulin antibodies in most cases. Other autoantibodies include anti-thyroid cell cytosol and anti-microsomes associated with HLA-DR5 and other autoimmune diseases such as vitiligo and SLE.
The patient, typically a postmenopausal female, presents with a diffuse goitre. Although most patients are euthyroid, thyrotoxicosis can occur and if presentation is late, hypothyroidism may be present. On examination, the thyroid is firm and symmetrically enlarged with a bosselated surface.
The thyroid is diffusely enlarged and has a fleshy white cut surface due to lymphocytic infiltration, which is seen on microscopy around the destroyed follicles.
High titres of circulating antithyroid antibodies, associated with a goitre on examination.
Thyroxine may cause regression of small goitres. Large goitres require subtotal thyroidectomy if causing compression of local structures such as the oesophagus or trachea. Surgical complications include damage to the recurrent laryngeal nerves or parathyroids. Post-surgery or following significant thyroid destruction patients become hypothyroid requiring treatment with thyroxine for life.