Primary thyroid lymphoma: evaluation with CT.

Abstract
The appearance of primary thyroid lymphoma on computed tomographic (CT) scans and clinical data for 15 patients were analyzed. The CT appearances were classified into three types: 12 patients (80%) had a solitary nodule (type 1), two (13%) had multiple nodules (type 2), and one (7%) had a diffuse goiter (type 3). In 47% of cases, both lobes were involved. The tumors had a strong tendency to compress (80%) or infiltrate (53%) the surrounding structures. The frequency of calcification (7%) or necrosis (7%) was low. Most patients (87%) had a rapidly enlarging thyroid mass, and six (40%) complained of symptoms from obstruction. All patients had coexistent Hashimoto thyroiditis. In 13 of 15 patients (87%), a highly probable diagnosis of thyroid lymphomas was determined with CT and clinical findings. A staging workup with CT and clinical findings confirmed at biopsy will allow appropriate therapy and may lead to improved prognosis for patients with this condition.