title: Renal neoplasms mimicking rhabdoid tumor of kidney. A report from the National Wilms' Tumor Study Pathology Center.
abstract: Fifty-six renal neoplasms reviewed by the National Wilms' Tumor Study Pathology Center presented with histologic features that resulted in confusion with rhabdoid tumor of kidney, a usually lethal childhood renal tumor; all were eventually diagnosed as other entities. Conspicuous filamentous cytoplasmic inclusions or large nucleoli, typical findings in rhabdoid renal tumors, were the usual source of diagnostic difficulty. Most, but not all, tumors occurred in pediatric patients. Sixteen were examples of Favorable Histology Wilms' tumor, which invited confusion with rhabdoid tumors either on the basis of filamentous cytoplasmic inclusions (15 cases) or macronucleoli (one case). In most cases, foci of typical Wilms' tumor blastemal aggregation or evidence of definitive nephrogenic differentiation facilitated the correct diagnosis. All 10 patients for whom information about outcome was available were alive at last follow-up. The other 40 renal lesions mimicking rhabdoid tumor of kidney consisted of a clinically and histogenetically diverse group of neoplasms, including anaplastic Wilms' tumor, congenital mesoblastic nephroma, renal cell carcinoma, transitional cell carcinoma, collecting-duct carcinoma, oncocytoma, rhabdomyosarcoma, malignant neuroepithelial tumors, and lymphoma. Most of these lesions could be separated from renal rhabdoid tumors and correctly classified on the basis of careful attention to light microscopic details, but in several cases electron microscopy or immunocytochemical studies were helpful or essential.
authors.affiliation: Department of Pathology, Loma Linda University, California 92350.
authors.forename: D A
authors.initials: DA
authors.lastname: Weeks
authors.forename: J B
authors.initials: JB
authors.lastname: Beckwith
authors.forename: G W
authors.initials: GW
authors.lastname: Mierau
authors.forename: C W
authors.initials: CW
authors.lastname: Zuppan
mesh_terms: D000236:Adenoma / Q000473:pathology; D000293:Adolescent; D000328:Adult; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000473:pathology; D002295:Carcinoma, Transitional Cell / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003594:Cytoplasmic Granules / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007680:Kidney Neoplasms / Q000473:pathology*; D008223:Lymphoma / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D009367:Neoplasm Staging; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000473:pathology; D012042:Registries; D012189:Retrospective Studies; D012208:Rhabdomyosarcoma / Q000473:pathology; D009396:Wilms Tumor / Q000151:congenital / Q000473:pathology*