Endocrine Abstracts

Introduction: Primary lymphoma of the thyroid, although rare, should be considered in the differential diagnosis of patients with thyroid nodules or goiter, because its prognosis and treatment differ substantially from that of the other disorders. Thyroid lymphomas are nearly always of the non-Hodking type (70–80% B cell lineage). There is a 4:1 female predominance and the mean and median ages at diagnosis are between 65 and 75 years. Hashimoto’s thyroiditis is the only known risk factor.

Case report: A 70 years old woman with a rapidly enlarging goiter without local symptoms or signs. The patient presented a history of hypothyroidism on treatment with thyroxine. Her tiroglobulin antibodies were positives but not TPO. An ultrasound scan of the thyroid showed a 7-cm mass in the left lobe and istm. The fine needle biopsy was nondiagnostic but suggestive of Hashimoto’s thyroiditis. The excisional biopsy confirmed the diagnosis of a diffuse large B-cell lymphoma. Imaging studies demonstrated cervical and mediastinal lymph nodes and bilateral pulmonary metastases.

Discussion: Thyroid lymphoma represents no more than 2% of all malignant thyroid tumors. The vast majority are of the non-Hodking type, the most frequent the B-cell lineage. The typical presentation is a rapidly enlarging goiter with symptoms or signs of tracheal, esophageal or neck vein compression. In 10–20% there is a known goiter often with hypothyroidism. Up to 10% have systemic (‘B’) symptoms of lymphoma (fever, night sweats, weight loss). Diagnosis is established by cytologic examination; when the fine needle biopsy is nondiagnostic the excisional biopsy is required. The treatment includes Radiaton and Chemotherapy. Definitive surgery is not usally performed. Our patient was treated with six cycles of CHOP followed by radiation.

Conclusions: Thyroid lymphoma is a rare cancer but must be considered in the differential diagnosis of patients with thyroid nodules or goiter specially if a Hashimoto’s thyroiditis is present. The risk of Thyroid lymphoma is at least 60 times higher than in patients without thyroiditis. The treatment is not the surgery like in the others thyroid pathologies and the prognosis depends on the type and tumour extension.