Thyroid Lymphoma

Epidemiology

Thyroid lymphoma constitutes 4% of all thyroid malignancies. It may arise primarily from the thyroid or involve the gland as part of a systemic disease. It is much more common in elderly women. The majority of patients with thyroid lymphoma have a history of Hashimoto’s thyroiditis.

Clinical Features

Patients generally present with a rapidly enlarging mass in the lower neck. Large masses can cause breathing or swallowing problems due to tracheal or esophageal compression. Pressure on the recurrent laryngeal nerve may cause hoarseness or aspiration secondary to vocal cord malfunction.

Pathology

The tumor is usually a B cell non-Hodgkin’s lymphoma. Lymphomatous involvement of the thyroid may be focal or diffuse. Grossly, the tumor appears as a firm, lobulated mass. Extension into the surrounding tissues occurs in 50 to 60% of cases. On histologic examination, the tumor is usually a diffuse large cell type. Low-grade lymphomas are less frequent and are usually the small cell type variant.

Treatment

Radiation therapy with or without chemotherapy is the most accepted form of treatment. Surgical resection is not recommended.

Imaging

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