The most common lymphomas of the thyroid are extranodal marginal zone B Cell lymphoma and diffuse large B cell lymphoma.
Epidemiology
Lymphoma of the thyroid is uncommon and makes up about 5% of malignant thyroid neoplasms. It is much more common in women (4:1) and usually occurs in older patients (over 65).
Aetiology
Extranodal marginal zone B Cell lymphoma of the thyroid is associated with autoimmune thyroid disease.
Natural History
Most cases present as isolated lymphoma involving the thyroid gland only (IE) or regional nodes (IIE). Dissemination of the disease depends on the histological type.
Clinical Features
The usual symptoms of thyroid masses can occur (hoarse voice, neck mass, vocal cord paralysis, or dysphagia). Evidence of hypothyroidism may be present due to the underlying condition.
Tumour Features
Lymphoma can present a broad range of appearances, from white and firm to soft and red. There is usually effacement of the normal gland. Microscopic appearance depends on the underlying type of lymphoma.
