CASE REPORT Syndrome of Megalencephaly, Polydactyly, and Polymicrogyria Lacking Frank Hydrocephalus, with Associated MR Imaging Findings

SUMMARY: Megalencephaly, polymicrogyria, polydactyly, and hydrocephalus (MPPH) syndrome has been recently recognized and is very rare. Each case reported so far has demonstrated hydrocephalus to varying degrees. We report an infant with MPPH syndrome, but lacking frank hydrocephalus. The additional finding of an abnormally elongated pituitary infundibulum has not been described in this syndrome and, along with the presence of a regressing cystic cavum septum pellucidum, suggests that chronic underlying hydrocephalus may have been present. Megalencephaly, polymicrogyria, polydactyly, and hydro-cephalus (MPPH) syndromewas first described in 2004, with only 9 cases reported so far; hence, the prevalence has not yet been determined.1,2 Hydrocephalus has been considered a mandatory component of this syndrome.1-4 We report a pa-tientwithmacrocephaly, polymicrogyria, andpolydactyly, but without overt hydrocephalus. We also report an elongated pi-tuitary infundibulum along with a regressing cystic cavum septum pellucidum (CSP); cystic CSP has been described pre-viously in MPPH, but without reports of regression.2,5,6 W