Singh M, Wu E, Shroyer K R
Department of Pathology, B216, University of Colorado Health Sciences Center, 4200 East 9th Avenue, Denver, Colorado 80262, USA.
Acta Cytol. 2001 May-Jun;45(3):454-8. doi: 10.1159/000327649.
Renal cell carcinomas have a high metastatic potential. Many of them are occult at initial presentation and mimic a primary neoplasm of the metastatic site. However, not all lymph node enlargements in a patient with a history of renal cell carcinoma are due to metastasis. Foamy macrophages can mimic metastatic renal cell carcinoma cells.
A 60-year-old male with a known diagnosis of renal cell carcinoma of clear cell type developed enlarged neck nodes 44 months after the diagnosis. These were aspirated to yield cystic fluid that, on smears, showed numerous clear cells with low nuclear grade. Immunohistochemical stains revealed these cells to be foamy macrophages (CD68 immunoreactive) and not metastatic renal cell carcinoma, as had been suspected on initial examination of Diff-Quik and Papanicolaou-stained smears.
Immunohistochemistry is a valuable adjunct in avoiding a false diagnosis of metastatic carcinoma in macrophage-rich nodal reactions in patients with a history of renal cell carcinoma.
肾细胞癌具有较高的转移潜能。其中许多在初次就诊时隐匿，并酷似转移部位的原发性肿瘤。然而，并非所有有肾细胞癌病史患者的淋巴结肿大都是由转移引起的。泡沫巨噬细胞可酷似转移性肾细胞癌细胞。
一名60岁男性，已知诊断为透明细胞型肾细胞癌，诊断后44个月出现颈部淋巴结肿大。对这些淋巴结进行穿刺抽吸，获得囊液，涂片显示大量核分级低的透明细胞。免疫组织化学染色显示这些细胞为泡沫巨噬细胞（CD68免疫反应阳性），而非如初次Diff-Quik和巴氏染色涂片检查时所怀疑的转移性肾细胞癌。
免疫组织化学对于避免在有肾细胞癌病史患者的富含巨噬细胞的淋巴结反应中误诊为转移性癌是一项有价值的辅助手段。
