The tumor cells are arranged in duct-like structures, irregular nests or infiltrate singly. Hobnail appearance, seen clearly in this duct, is a helpful diagnostic feature. The prognosis is generally poor.

• 肿瘤细胞呈管状结构样排列，偶尔可见不规则巢状结构和浸润改变。下图中，管内鞋钉样表现明显可见，有助于诊断。该类肾癌预后一般较差。