Haberland Syndrome (Encephalocraniocutaneous Lipomatosis) with Development of Diffuse Leptomeningeal Glioneural Tumor (DL-GNT) during Adolescence

Excerpt

Haberland syndrome or encephalocraniocutaneous lipomatosis (ECCL) is a rare ectomesodermal dysgenesis defined by the involvement of multiple systems, including: eyes; skin; central nervous system, commonly unilateral; bone. It was first recognized in 1970, and about 160 patients have been reported. This disorder is a rare sporadic RASopathy due to one of two mutually exclusive fibroblast growth factor receptor 1 (FGFR1) mutations p.N546K or p.K656E. These activating hotspot mutations are identified in affected tissues but not in the peripheral blood of ECCL patients and are likely the result of postzygotic constitutional mosaicism promoting locally constitutive activation of the RAS-MAPK pathway. The same FGFR1 mutations occur in subgroups of sporadic low-grade gliomas (LGG), indicating a probable intersection between ECCL and tumorigenesis, a possibility further substantiated by reports of brain tumors in ECCL cases with wide-ranging histopathological subtypes [1]. We report the first described case of an adolescent with Haberland syndrome who developed a diffuse leptomeningeal glioneural tumor (DL-GNT). The development of DL-GNT in this case strongly suggests that close clinical and radiological follow-up is essential in children with established ECCL. …