Case 1. Magnetic resonance imaging (MRI) and macroscopy. (A-B) T2-weighted MRI showing hyperintense, multinodular solid lesions in the subcortical white matter of the medial part of the left superior frontal gyrus without tissue expansion or mass effect (white arrow). (C) Coronally sectioned surgically removed material reveals coalescing grey nodules (black arrow) (bar = 5 mm). (D) Low power microscopy demonstrates hypomyelinated plaque-like nodules extending into the deep cortex (Luxol fast blue – Nissl) (bar = 1 mm).