婴儿骨化性肾肿瘤的临床病理观察

目的探讨婴儿骨化性肾肿瘤的临床病理特点、组织起源及其诊断和鉴别诊断。方法对1例婴儿骨化性肾肿瘤的临床、影像学和病理特征进行观察并复习文献。结果患儿因肉眼血尿入院,影像学检查提示左肾下极钙化性肿物和左下肾盏、肾盂变形。大体见肿物包膜完整,灰白、灰黄色,略呈结节状,剖面质硬,灰白色,局部呈囊性,可见出血;镜下肿瘤由骨样基质、成骨样细胞和梭形细胞组成;免疫组化染色示部分成骨样细胞vimentin、EMA和CK（＋）,梭形细胞vimentin（＋）,Ki-67〉5%（＋）,且阳性细胞主要是梭形细胞。结论婴儿骨化性肾肿瘤具有独特的临床表现、影像学改变及病理特征,是一种少见的良性肾肿瘤,预后良好。

Ossifying renal tumor of infancy:a clinicopathologic observation

Objective To study the clinicopathological features of ossifying renal tumor of infancy and to explore its histogenesis, diagnosis and differential diagnosis. Methods A case of ossifying renal tumor of infancy was analyzed with pathological morphology and immunohistochemical staining and review of the related literature. Results The infant was admitted to the hospital because of gross hematuria for 5 months. On radiological examination, a calcified mass was present in the lowerpole of the left kidney and resulted in some distortion of the left lower renal pelvis and calices. On pathologic examination, the lesion appeared well-encapsulated, gray-yellowish and a little nodular, The mass was predominantly hard and gray on cross surface. Cystic degeneration and hemorrhage were presented in local lesion, On light microscopy, the tumor appeared ill-defined with the renal parenchyma, consisted of osteoid islands, osteoblast-like cells and spindle cells. The osteoblast-like cells mederately coexpressed vimentin, EMA and CK, but did not express desmin. The spindle cells strongly expresed vimentin, but did not express EMA and CK. More than 5% cells expressed Ki-67, most of which were spindle cells. Conclusion Ossifying renal tumor of infancy has characteristics in clinic, radiology and pathology. It is a rare benign renal tumor with favorable outcome. The diagnosis and differential diagnosis of the tumor are important.