History: A 46-year-old man presents to the emergency department (ED) with neck fullness and abdominal pain. The patient moved to the U.S. from Liberia 10 years ago.
病史：46岁男性，因颈部肿胀、腹部疼痛就诊于急诊科，患者十年前曾从美国去过利比里亚。
A contrast-enhanced CT scan of the neck was performed. Axial and coronal images are shown below.
行颈部CT增强，轴位及冠状位如下所示。
Additional images
Further imaging was obtained due to the patient\’s nonspecific abdominal discomfort.
Contrast-enhanced CT scans of the chest and abdomen/pelvis were performed. Coronal, axial, and sagittal images are shown below.
由于患者腹部不适，进一步行胸腹盆CT增强，冠状、轴位及矢状图像如下所示。
Findings
Necrotic lymphadenopathy is seen through the cervical region, mediastinum, hila, abdomen, and retroperitoneum.
影像表现：
颈部、纵隔、肺门、腹腔及腹膜后见多发坏死性肿大淋巴结。
（补充：增强扫描呈环形强化）
Differential diagnosis
- Tuberculous lymphadenopathy
- Lymphoma
- Metastatic carcinoma
- Mycobacterium tuberculosis infection
- Nontuberculous mycobacterial infection
- Disseminated histoplasmosis infection
- Whipple disease
- Autoimmune disease (i.e., systemic lupus erythematosus)
鉴别诊断：
- 淋巴结结核
- 淋巴瘤
- 转移癌
- 结核分枝杆菌感染
- 非结核分枝杆菌感染
- 播散型组织胞浆菌病感染
- 惠普尔病
- 自身免疫性疾病（如：系统性红斑狼疮）
Diagnosis: Tuberculous lymphadenopathy, biopsy-proven
诊断：淋巴结结核（活检证实）
Key points
Tuberculous lymphadenopathy
Background
- Tuberculosis (TB) is typically confined to the respiratory system.
- However, it can affect any organ system, and immunocompromised patients have an increased risk of extrapulmonary TB.
- Radiographic evidence of lymphadenopathy is seen in more than 95% of children and over 40% of adults with TB.
- Lymphadenopathy as the only evidence of TB radiographically is more common in infants and decreases in frequency with age.
背景：
- 结核（TB）通常局限于呼吸系统；
- 然而，也可以累及其它器官，免疫缺陷人群更易患肺外结核；
- 超过95%的儿童及超过40%的成人结核患者影像学可发现淋巴结肿大；
- 婴儿常常仅表现为淋巴结肿大，这种情况随年龄增加而减少。
Imaging
CT：
- Lymph nodes larger than 2 cm often have a low attenuation center from necrosis and are suggestive of active disease.
- Cervical TB lymphadenopathy is often the first site of extrathoracic lymph node involvement; known as scrofula or cervical TB lymphadenitis.
影像表现（CT）：
- 淋巴结大于2cm时常由于坏死而表现为中心低密度，提示疾病处于活动期；
- 颈部结核性淋巴结肿大常是胸外淋巴结受累的第一站，被称作淋巴结结核或颈部结核性淋巴结炎。
Diagnosis
- Outside of the U.S., up to 50% of patients with chronic lymphadenopathy have TB as the causative etiology. However, malignancy is a significant alternative diagnosis.
- Thus, a biopsy is thus recommended to confirm TB and exclude other diagnoses.
诊断：
- 在美国以外的地方，多达50%的慢性淋巴结肿大患者的病因为结核；然而，恶性肿瘤是一个重要的替代诊断；
- 因此，需活检证实为TB，除外其他诊断。
几例淋巴结结核、肿瘤
女，2岁，30余天前无明显诱因下出现左侧颈部肿物，起初小，约1×1cm，进行性增大，皮肤表面无红肿、发热，无溃烂，当地医师给予草药局部外敷，无明显疗效。
左颈部明显肿大淋巴结，密度、信号不均匀，内见斑点状无强化坏死囊变区，增强扫描大部分区域呈明显强化。
术后病理：颈部包块：灰白灰红色类圆形肿物一枚，大小4x3x3.3cm，切面灰黄灰红相间；颈淋巴结2枚，1枚米粒大，另一枚灰白灰红色，类圆形，大小1×0.6×0.3cm。送检颈部包块及颈部淋巴结见淋巴结结构，淋巴结组织内多处可见多个片状的干酪样坏死组织，周围可见较多由类上皮样细胞及郎罕氏巨细胞构成的结核结节，其间散在多少不等的淋巴细胞浸润。在病变组织边缘见少量横纹肌及脂肪组织，未见确切腮腺组织。
（左颈部）淋巴结结核
女，17岁，发现右侧颈部肿物十余天。
右颈部多发增大淋巴结，增强扫描均可见坏死区。
入院后完善检查，PPD试验（ ），血沉明显加快，颈部包块细胞学活检示符合颈部淋巴结结核。
男，28岁，无意间发现右颈部包块，无疼痛，无发热、盗汗。
行手术切除，术后病理：淋巴结结核
男性，71岁，发现颈部包块1天。
（颈部淋巴结穿刺）转移性鳞状细胞癌
男33岁，颈部无痛性肿物3月余，质硬，活动度差，轻度触痛。
左颈部淋巴结鳞状细胞癌
鉴别诊断要点
- 年龄：结核多见于幼儿、青少年；转移癌多见于中老年；
- 全身情况：临床症状，有无肺结核（不一定有）；有无原发肿瘤（不一定能找到）；
- 影像表现：结核的坏死区相对边界较清楚，淋巴结之间边界相对清晰，无明显融合趋势；转移癌的坏死区多欠光整，淋巴结周围毛糙，易融合成团；
- 建议：病理学检查。