Primary lymphoma of the thyroid.

Primary lymphoma is an uncommon malignancy of the thyroid, comprising between 0.6 and 5 per cent of thyroid cancers in most series. This report is presented because of a 10 per cent (6 of 60) incidence of this cancer at one institution. A short history of a rapidly enlarging neck mass often associated with dyspnea, difficulty swallowing, or voice change is the hallmark presentation of thyroid lymphoma. The majority of patients are women with a mean age in the 6th decade. Although fine-needle aspiration has become the procedure of choice for the diagnosis of a thyroid nodule, it has yielded mixed results with the presence of lymphoma. The majority of thyroid lymphomas are diffuse, large cell lesions of B-cell origin. Controversy remains as to the role of surgery in thyroid lymphomas. Within the improvement in results with the use of radiotherapy and chemotherapy alone or in combination, some authors have advocated relegating surgery to the role of diagnosis only. This can be accomplished by fine-needle aspiration, core biopsy, or open biopsy. Others have favored a more aggressive surgical approach, showing that the amount of residual disease after debulking procedures was directly correlated with local and distant recurrences. A lack of randomized prospective studies makes it difficult to resolve this issue. The rates of complications of surgery, including hypocalcemia and recurrent laryngeal nerve damage, are higher than for operations for other types of thyroid malignancy. Improved prognosis has been associated with the following factors: disease limited to the thyroid, the absence of dysphagia, primary mass less than 10 cm, tumors without necrosis, and tumors consisting of plasmacytomas.