Patel Nilesh P, Geisinger Kim R, Zagoria Ronald J, Bergman Simon
Department of Pathology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157-1070, USA.
Acta Cytol. 2009 May-Jun;53(3):327-31. doi: 10.1159/000325319.
Metanephric adenoma (MA) is a rare, benign renal neoplasm. Only 3 previous case reports describe the fine needle aspiration biopsy (FNAB) cytologic features of MA. Regarding treatment, radioflrequency ablation (RFA) is an emerging alternative to surgical resection of renal neoplasms in appropriately selected patients.
A 49-year-old woman had a 3.3-cm cortical mass in the left kidney. Computed tomography-guided FNAB was performed, followed by RFA of the lesion. The aspirate smears displayed multiple aggregates of benign-appearing, tightly packed and overlapping nuclei surrounded by basement membrane- type material. The cohesive aggregates were arranged in tubular or tubulopapillary structures without fibrovascular cores. No atypia, mitotic figures or necrosis were present. Immunohistochemical (IHC) stains performed displayed positive staining for WT-1, CD57 and cytokeratin AE1/AE3 and equivocal staining for CD56. The AMACR, CK7 and EMA immunostains were negative. Although the differential diagnosis included adult Wilms' tumor and papillary renal cell carcinoma, the bland morphology and IHC staining pattern strongly favored a neoplasm consistent with MA.
FNAB can be used to diagnose most renal neoplasms. A diagnosis of MA can be suggested on FNAB in the context of appropriate cytomorphology, IHC staining and cytogenetic analysis.
后肾腺瘤（MA）是一种罕见的良性肾肿瘤。此前仅有3例病例报告描述了MA的细针穿刺活检（FNAB）细胞学特征。关于治疗，对于经过适当选择的患者，射频消融（RFA）是肾肿瘤手术切除的一种新兴替代方法。
一名49岁女性左肾有一个3.3厘米的皮质肿块。进行了计算机断层扫描引导下的FNAB，随后对病变进行了RFA。吸出物涂片显示多个良性外观的聚集物，细胞核紧密排列且相互重叠，周围有基底膜样物质。这些有黏附性的聚集物排列成管状或小管乳头状结构，无纤维血管轴心。未见异型性、核分裂象或坏死。免疫组织化学（IHC）染色显示WT-1、CD57和细胞角蛋白AE1/AE3呈阳性染色，CD56染色不明确。AMACR、CK7和EMA免疫染色均为阴性。尽管鉴别诊断包括成人威尔姆斯瘤和乳头状肾细胞癌，但平淡的形态学和IHC染色模式强烈提示肿瘤符合MA。
FNAB可用于诊断大多数肾肿瘤。在适当的细胞形态学、IHC染色和细胞遗传学分析的背景下，FNAB可提示MA的诊断。
