title: Fine-needle aspiration of renal angiomyolipoma: cytological findings and diagnostic pitfalls in a series of five cases.
abstract: Diagnosis of renal angiomyolipoma (AML) by fine-needle aspiration (FNA) may be difficult because cytological and radiological findings sometimes overlap with renal cell carcinoma (RCC) and liposarcoma. Five FNAs of AMLs were studied. Epithelioid and spindle stromal cells were arranged in loosely cohesive clusters and singly. The chromatin was evenly distributed and bland. Occasionally nuclear atypia was identified. Nuclei were oval to elongated, nucleoli were inconspicuous or absent, naked nuclei were present in three specimens, and intranuclear inclusions were present in two specimens. The cytoplasm was delicate and sometimes finely vacuolated. Adipose tissue was observed in two specimens. Thick-walled vessels, mitoses, and necrosis were absent. Corresponding surgical material showed typical features of AML. In FNA, bland chromatin and inconspicuous nucleoli distinguish renal AML from RCC and liposarcoma. Adipose tissue is not universally present. Cellular atypia in conjunction with overlapping radiological findings with RCC and liposarcoma are potential diagnostic pitfalls. Immunocytochemical (ICC) stains may elucidate the correct diagnosis.
authors.affiliation: Cytology Service, Department of Pathology, Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, New York, USA. joc2034@med.cornell.edu
authors.forename: John P
authors.initials: JP
authors.lastname: Crapanzano
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis; D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D044963:Biopsy, Fine-Needle / Q000379:methods*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis; D003937:Diagnosis, Differential; D015622:Epithelioid Cells / Q000473:pathology; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008080:Liposarcoma / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis; D017154:Stromal Cells / Q000473:pathology