Safety of trastuzumab after trastuzumab emtansine-induced nodular regenerative hyperplasia: A case report.

Based on fundamental studies, nodular regenerative hyperplasia is probably caused by the emtansine (DM1) part of the trastuzumab emtansine. It is still unclear if trastuzumab therapy can be reintroduced after nodular regenerative hyperplasia induced by trastuzumab emtansine, depriving the patient of a HER2-targeted therapy. Only one case reported having given trastuzumab in this situation over one month. In our case, trastuzumab was reintroduced without any complications for a long extent following TDM1-associated nodular regenerative hyperplasia.