Carrillo Amber, Arbab Farinaz, Ramani Nisha S
Department of Pathology and Immunology, Baylor College of Medicine, Houston, USA.
Department of Pathology and Immunology, Michael E. DeBakey Department of Veterans Affairs Medical Center, Houston, USA.
Cureus. 2025 May 21;17(5):e84554. doi: 10.7759/cureus.84554. eCollection 2025 May.
Papillary thyroid carcinoma (PTC) is the most common thyroid neoplasm. While its initial presentation as metastasis is not uncommon, metastasis to the lymph nodes without a primary tumor is extremely rare. Here we report an unusual case of metastatic PTC within the lymph nodes without an identifiable primary tumor in the thyroid gland. We report a case of a 45-year-old man who presented with neck swelling detected on a routine physical examination. The patient was asymptomatic, and his thyroid function was normal. Ultrasound of the thyroid revealed a well-circumscribed isoechoic 4.5 cm mass in the mid/lower pole of the right lobe. The patient had a congenitally absent left thyroid lobe. CT neck showed no evidence of cervical lymphadenopathy. Fine-needle aspiration was suspicious for a neoplasm, and surgical excision was recommended. The patient then underwent right thyroid lobectomy and isthmusectomy. Gross examination of the thyroid revealed two nodules (4.4 cm and 2 cm) in the right lobe. The entire lobe and isthmus, including the two nodules, were submitted for histologic evaluation, which revealed two encapsulated lesions with microfollicular architecture. The cells displayed hyperchromatic small round cuboidal nuclei with absent nuclear features of PTC. These findings were consistent with follicular adenomas. Interestingly, two of the six central neck lymph nodes were positive for subcapsular metastatic PTC.
甲状腺乳头状癌(PTC)是最常见的甲状腺肿瘤。虽然其最初表现为转移并不罕见,但无原发肿瘤的淋巴结转移极为罕见。在此,我们报告一例罕见的淋巴结内转移性PTC病例,甲状腺内未发现可识别的原发肿瘤。我们报告一例45岁男性,在常规体检时发现颈部肿胀。患者无症状,甲状腺功能正常。甲状腺超声显示右叶中/下极有一个边界清晰的等回声4.5厘米肿块。患者先天性左甲状腺叶缺如。颈部CT未显示颈部淋巴结病迹象。细针穿刺活检怀疑为肿瘤,建议手术切除。患者随后接受了右甲状腺叶切除术和峡部切除术。甲状腺大体检查显示右叶有两个结节(4.4厘米和2厘米)。整个叶和峡部,包括两个结节,均送去做组织学评估,结果显示有两个具有微滤泡结构的包膜性病变。细胞显示核深染的小圆形立方形核,无PTC的核特征。这些发现符合滤泡性腺瘤。有趣的是,颈部中央六个淋巴结中有两个出现包膜下转移性PTC阳性。