A child with hemimegalencephaly, hemihypertrophy, macrocephaly, cutaneous vascular malformation, psychomotor retardation and intestinal lymphangiectasia--a diagnostic dilemma.

Although the clinical delineation of the majority of overgrowth syndromes is straightforward, we believe there is a subset of patients with overlapping features from a number of overgrowth syndromes. We report a patient with hemimegalencephaly, hemihypertrophy, macrocephaly, vascular lesions, psychomotor retardation and intestinal lymphangiectasia. The clinical history and findings posed a diagnostic dilemma as the features overlapped between several conditions, namely macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC), Klippel-Trenaunay-Weber syndrome (KTWS), Proteus syndrome and a provisional unique syndrome described by Reardon et al. (1996, Am J Med Genet 66:144-149). We anticipate that only when the molecular basis is delineated will it become clear whether these disorders are separate entities or merely differing ends of the same spectrum.