Revisiting a Rare Anomaly Described 25 Years Ago in the AJNR: A Journey from Pediatric Hemifacial Microsomia and Middle Cranial Fossa Aplasia to CSF-Lymphatic Fistula and Spontaneous Intracranial Hypotension as an Adult.

This report presents a unique case of a 39-year-old woman with a congenital unilateral aplasia of the middle cranial fossa floor associated with atypical hemifacial microsomia, initially described in a case report at age 14, who later developed a transosseous CSF-lymphatic fistula through the C1 vertebral body. Dynamic CT cisternography confirmed the diagnosis, and a transnasal percutaneous fibrin glue occlusion successfully reversed the patient's brain sag and improved her symptoms. This case highlights the evolving understanding of CSF dynamics and the diagnostic and therapeutic challenges posed by rare CSF leak variants.