Transformation of a non-secretory neuroendocrine tumor to insulinoma after treatment with Sunitinib: A case report and review of the literature.

We report a case of a non-secretory neuroendocrine tumor which transformed into an insulin secreting tumor after treatment with Sunitinib. To our knowledge, this has only been described in three other cases worldwide. Previously reported case series find transformation of non-secretory neuroendocrine cancers into secretory lesions occurs in 3.4-6.8% of cases. Sunitinib is known to have the potential to lower blood glucose and induce epigenetic changes in cells of various types. We hypothesize that the mechanism for Sunitinib-induced transformation in cancer phenotype is through epigenetic changes in DNA expression within the tumor cells.