肿瘤分化很差，以至于很难判断组织来源。这可能是一种源于多形性细胞的一种癌。在肿瘤细胞中核多且大。未分化肿瘤被称为退化发育。

This neoplasm is so poorly differentiated that it is difficult to tell what the cell of origin is. It is probably a carcinoma because of the polygonal nature of the cells. Note that nucleoli are numerous and large in this neoplasm. Neoplasms with no differentiation are said to be anaplastic.