学童期に発症したmalignant rhabdoid tumor of the kidney（MRTK）の1例

A case of malignant rhabdoid tumor of the kidney in a school-aged child

腎横紋筋肉腫様腫瘍（malignant rhabdoid tumor of the kidney：MRTK）は小児腎腫瘍の約2％を占めるまれな悪性腫瘍である。約80％が2歳未満の小児に発生し，発症時年齢中央値は11カ月と乳幼児に多い疾患である^1）。今回我々は8歳女児に発症したMRTKの症例を経験したので報告する。

The patient was an 8-year-old girl with left back pain and weight loss. Contrast-enhanced CT showed unclear boundary inhomogeneous enhanced left renal mass and subcapsular enhancing soft tissue component and fluid collection. The mass contained necrotic low-density area and linear calcification. The patient underwent a radical nephrectomy. Because the tumor cells were the lack of immunohistochemical staining for the INI1 gene product, we diagnosed a malignant rhabdoid tumor of the left kidney.