title: Cystic partially differentiated nephroblastoma in an adult: a case imitating the process of normal nephrogenesis along with corresponding WT1 expression.
abstract: Cystic partially differentiated nephroblastoma (CPDN) is extremely rare in adults. Only 2 cases have been documented in the English literature. Herein, we present a third case of CPDN with unique morphological and immunohistochemical features. A 45-year-old man had a multicystic right renal mass, with a maximum diameter of 3 cm on magnetic resonance imaging. Being unable to rule out malignancy, partial nephrectomy was performed. The surgically resected specimen contained a multicystic mass, 3 × 3 × 2.5 cm in size, without an expansile solid nodule. Histopathological examination revealed nephroblastomatous elements without identifiable blastema; transition from cap-mesenchyme-like cells to an immature glomerulus was observed and maturing tubules and a glomerulus were present. Despite the lack of a blastema, the diagnosis of CPDN was the most appropriate. Immunohistochemical WT1 expression imitated the pattern of ongoing normal nephrogenesis. Therefore, we believe that the blastema disappeared because of maturation.
authors.affiliation: Department of Pathology, Shizuoka Saiseikai General Hospital Shizuoka, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine Shizuoka, Japan.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Waki
mesh_terms: D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D025721:WT1 Proteins / Q000096:biosynthesis*; D009396:Wilms Tumor / Q000378:metabolism / Q000473:pathology*
chemical_list: D025721:WT1 Proteins; C583751:WT1 protein, human
keywords: Cystic partially differentiated nephroblastoma; WT1; adult; maturation; nephrogenesis