Fine-needle aspiration of metanephric adenoma of the kidney with clinical, radiographic and histopathologic correlation: A review

• Published in: Diagnostic cytopathology Vol. 41; no. 8; pp. 742 - 751
• Main Authors: Blanco Jr, Luis Z., Schein, Caitlin O., Patel, Tushar, Heagley, Dawn E., Cimbaluk, David J., Reddy, Vijaya, Gattuso, Paolo
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-08-2013; Wiley Subscription Services, Inc
• Subjects: Adenoma - diagnostic imaging; Adenoma - pathology; Aged; Biopsy, Fine-Needle; cytologic features; Diagnosis, Differential; Female; fine-needle aspiration; Humans; kidney; Kidney Neoplasms - diagnostic imaging; Kidney Neoplasms - pathology; metanephric adenoma; Middle Aged; Radiography; Wilms Tumor - diagnostic imaging; kidney; cytologic features; fine-needle aspiration; metanephric adenoma
• ISSN: 8755-1039; 1097-0339
• DOI: 10.1002/dc.22962

Metanephric adenoma of the kidney is an uncommon benign epithelial neoplasm with only a small number of reports that describe its cytologic features. We describe two additional cases of metanephric adenoma diagnosed on fine‐needle aspiration biopsy and review the available literature. Our cases showed similar cytology and were composed of cellular smears with numerous clusters of small, oval to round cells arranged in a microfollicular pattern and papillary configurations. The tumor cells had scant cytoplasm, fine chromatin and absent nucleoli. Psamomma bodies, nuclear atypia, cellular cpleomorphism, necrosis, and mitoses were absent. Because of the rarity of this tumor and the common cytologic features it shares with other lesions, including malignant tumors such as Wilms’ tumor and papillary renal cell carcinoma, awareness of the cytologic features of metanephric adenoma may aid in avoiding a diagnosis of malignancy, especially preoperatively, and in guiding the proper management for the patients. Diagn. Cytopathol. 2013;41:742–751. © 2013 Wiley Periodicals, Inc.