title: Metanephric stromal tumor: a challenging diagnostic entity in children.
abstract: A case with a renal mass diagnosed as metanephric stromal tumor is presented. A 6-year-old boy presented with frequently recurring urinary tract infections. He had been followed up at different medical centers for the last 2 years with a 2 × 2 cm simple cyst localized in the inferior pole of the left kidney. At our center, ultrasonography revealed a heterogeneous mass in the left kidney with a central cystic component. The patient underwent operation for left renal mass, and heminephrectomy was performed. The 5 × 4 × 2.5 cm left heminephrectomy specimen showed a partially cystic mass composed of bland spindle cells distributed haphazardly, entrapping tubules and glomeruli and producing fine collarettes around some tubules. The cysts were lined with a 1-layered flat or cuboidal epithelium. Histopathologically, the tumor was diagnosed as metanephric stromal tumor. Metanephric stromal tumor is a rare renal neoplasm of childhood that can present as a cystic mass, and the solid component can go radiologically undetected because of the blurring infiltrative margins. By presenting this rare entity, the authors suggest that this should be included in the differential diagnosis, thereby helping to avoid complications and unnecessary treatment.
authors.affiliation: Department of Pathology, Ankara Child Diseases Hematology Oncology Training and Research Hospital, Ankara, Turkey. ayperkacar@yahoo.com
authors.forename: Ayper
authors.initials: A
authors.lastname: Kacar
authors.forename: Müjdem Nur
authors.initials: MN
authors.lastname: Azili
authors.forename: Birsen Songül
authors.initials: BS
authors.lastname: Cihan
authors.forename: Haci Ahmet
authors.initials: HA
authors.lastname: Demir
authors.forename: Hüseyin Tugrul
authors.initials: HT
authors.lastname: Tiryaki
authors.forename: Pedram
authors.initials: P
authors.lastname: Argani
mesh_terms: D000071443:12E7 Antigen; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D000951:Antigens, Neoplasm / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D015815:Cell Adhesion Molecules / Q000032:analysis; D002648:Child; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000175:diagnosis*; D007680:Kidney Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008297:Male; D009392:Nephrectomy / Q000379:methods; D018201:Nephroma, Mesoblastic / Q000175:diagnosis; D018227:Sarcoma, Clear Cell / Q000175:diagnosis; D014552:Urinary Tract Infections / Q000209:etiology; D014718:Vesico-Ureteral Reflux / Q000150:complications; D009396:Wilms Tumor / Q000175:diagnosis
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules