Renal Metanephric Adenofibroma

Metanephric adenofibroma is a rare benign biphasic renal tumor. We present a 2.5 year-old girl who was admitted to Mofid Children’s Hospital with abdominal mass for a few months and constipation. Physical exam showed a hard RUQ abdominal mass extending to the pelvis. Color Doppler sonography of Kidney showed a 11.4x8.4 cm heteroecho mass in Rt kindey with patent inferior vena cava. Abdominopelvic spiral CT scan with contrast media revealed a 11.2x1.3x9.9 cm heterogenous Rt kidney mass. Whole body bone scan demonstrated abnormal activity in Rt renal fossa with extension to midline; Rt kidney was not visualized (suggestive of abdominal soft tissue mass, possibly neuroblastoma with probable involvement of Rt kidney and adjacent ribs. Spiral CT scan of thorax with contrast was normal. BM did not show any evidence of malignancy. With the clinical impression of Wilm’s tumor, the patient underwent Rt radical nephrectomy.The specimen consisted of a tumoral kidney measuring 13x10x9 cm and 633 grs. Cut surfaces showed almost total replacement of kidney by a well-defined, tan, solid, nodular 11x10x9 cm mass with a 2 cm rim of non tumoral kidney. Renal sinus was not involved by the tumor. Microscopic examination showed a biphasic neoplasm composed predominantly of stromal component revealing fascicles of mildly pleomorphic spindle cells with hypercellular and hypocelluar areas, myxoid change, cystic spaces and foci of hemorrhage and necrosis, infiltrating the renal tissue. The epithelial component was composed of well-defined nodules of papillary and glandular structures with small uniform round cells, scant cytoplasm and multiple foci of calcifications with psammoma bodies. Mitotic activity was low and there was no atypia. This case is presented due to its rarity and the possibility of being misdiagnosed as a malignant tumor.

کلیدواژه ها:

Kidney ، metanephric adenofibroma