Primary Hepatic Neuroendocrine Tumor with Unusual Thyroid Follicular-Like Morphologic Characteristics

Table 1

World health organization classification of gastroenteropancreatic neuroendocrine tumors.

Grade	Origin
Low	<2 mitoses/10 HPFs and <3% Ki-67 index
Intermediate	2–20 mitoses/10 HPFs or 3%–20% Ki-67 index
High	>20 mitoses/10 HPFs or >20% Ki-67 index

HPF, high-power field.
(Adapted from Klimstra et al. [16]).