原发性甲状腺淋巴瘤的临床和CT表现

Clinical and CT imaging features of primary thyroid lymphoma

背景与目的：原发性甲状腺淋巴瘤（primary thyroid lymphoma，PTL）较为少见，临床处理不同于甲状腺其他恶性肿瘤，因此，认识PTL具有重要意义。该研究旨在分析PTL的临床及CT表现。方法：收集22例经病理证实为PTL患者的临床和影像学资料，回顾性分析其临床症状，包括肿瘤的部位、大小、形态、边缘、CT密度及强化方式、与周围组织关系和颈部淋巴结情况。结果：22例患者中男性8例，女性14例，年龄范围39-77岁，平均年龄60岁。临床症状表现为短期内肿块迅速增大者12例。肿瘤累及双侧11例，累及单侧8例，同时累及右侧及峡部3例。肿瘤长径范围12-104 mm，短径范围11-71 mm。弥漫型、多发结节型和孤立结节型分别为12、5和5例。CT平扫15例低密度，7例等密度，肿瘤内部发现钙化0例，坏死5例。增强后19/22例轻中度强化，3/22例明显强化。CT增强均质密度13例，混杂密度9例。17例气管受压，5例食管受压，12例病灶突入前上纵隔内，8例颈部见肿大淋巴结。结论：老年女性颈部肿块迅速增大，CT表现为均质、低密度、轻中度强化、弥漫性肿大的实质性肿块，伴有邻近组织的压迫及侵犯，提示PTL可能。

Background and purpose： Primary thyroid lymphoma （PTL） is uncommon in clinic with quite different treatment from that of other malignant thyroid tumors. Therefore, to achieve complete understanding of PTL has crucial significance. This study aimed to investigate the clinical and computed tomography （CT） characteristics of PTL. Methods： The clinical and imaging data from 22 patients with PTLs confirmed by pathology were collected. The clinical symptoms of patients, the site, size, shape, margin, CT value and enhancement pattern, relation with surrounding tissues of PTLs and cervical lymph nodes were summarized retrospectively. Results： All the 22 patients including 8 males and 14 females had an average age of 60 years （range： 39-77 years）. Twelve PTLs rapidly progressed in short term and the rest expanded slowly. The tumors involved bilateral thyroid in 11 cases, unilateral thyroid in 8 cases and both right lobe and isthmus in the remaining 3 cases. The long and short ranges were （12-104） mm and （11-71） mm. The solitary, multiple and diffuse nodules distributed in 5, 5 and 12 patients, respectively. In axial plain CT scans, low density appeared in 15 patients, isodensity in 7 patients, calcification inside the lesion in 0 patient, and necrosis in 5 patients. Nineteen PTLs manifested slight or moderate enhancement, and 3 marked enhancement in contrast-enhanced axial CT images. Homogeneous density and mixed density were demonstrated in 13 and 9 cases, respectively. Trachea and esophagus was pushed in 17 and 5 cases, tumors were involved into superior mediastinum in 12 cases and enlarged lymph nodes were demonstrated in 8 cases. Conclusion： If a solid thyroidal mass in an old female patient rapidly progresses in short term and CT scans show homogeneous and low density, slight or moderate enhancement, and diffusive swelling with compression and invasion of surrounding tissues, it has a high possibility of PTL.