MUC5AC and inflammatory myofibroblastic tumor: The WHO CNS5 established the following essential diagnostic criteria for IMT, FET::CREB fusion-positive: 1/ primary intracranial location; 2/ variable morphological features including spindle cells, mucin-rich stroma, haemangioma-like vasculature, or epithelioid cells in a mucin-poor collagenous stroma; 3/ demonstration of a FET::CREB family fusion.