Identification of primary thyroid lymphoma with medical imaging: A case report and review of the literature

Abstract

Primary thyroid lymphoma (PTL) is a rare thyroid malignancy. Clinical diagnosis of PTL may not be easily established based on imaging studies, as the imaging features of PTL are similar to those of lymphocytic thyroiditis and primary thyroid cancer. The present study describes the case of a patient who was confirmed to have PTL by intra-operative pathological diagnosis. On color Doppler ultrasound, the PTL was shown as a significantly enlarged thyroid with reduced gland echoes. Color Doppler flow imaging showed increased blood flow. By computed tomography, the thyroid was revealed to be enlarged with reduced tissue density, particularly in the left lobe and the isthmus. In addition, calcified spots and swollen lymph nodes were evident. The clinical history of the patient was obtained and the imaging results were retrospectively analyzed. The imaging features of PTL were investigated through reviewing the literature. PTL exhibits specific features on medical imaging that aid in distinguishing it from other thyroid diseases. PTL exhibits specific features on medical imaging that aid in distinguishing PTL from other thyroid diseases, which may aid the support for clinical diagnosis and improve the clinical accuracy.

Keywords: computed tomography; imaging features; primary thyroid lymphoma.

Figure 1

Color Doppler ultrasound demonstrating (A) non-uniform hypoechoic signals and an indication of calcified spots (white arrows). (B) Color Doppler flow imaging indicted increased blood flow signals.

Figure 2

Multi-planar reconstruction computed tomography image of the neck shows a significantly enlarged thyroid, particularly in the left lobe and the isthmus, with reduced tissue density. The lesion extends from the upper level of the third cervical vertebra to the arterial arch, and presses the surrounding structures toward the right side. (A) Transversal view, (B) coronal view and (C) sagittal view.

Figure 3

Pathological confirmation of non-Hodgkin’s lymphoma by diffuse proliferation of large atypical lymphocytes, large nuclei with coarse nuclear reticulum, including several small nucleoli, and the appearance of mitosis (staining, hematoxylin and eosin; magnification, ×20).