Cutaneous manifestations and massive genital involvement in Hennekam syndrome.

We describe a 16-year-old boy with intestinal lymphangiectasia, lymphedema of the limbs and genitalia, mild mental retardation, and facial anomalies (Hennekam syndrome) and cutaneous lesions. Severe edema in the genital area created a gigantic mass that included the scrotum and penis. Numerous grouped red-violaceous pseudo-vesicular lesions and plaques, as well as verrucous brown papules, were present on the penis and scrotum. The prepuce was hypertrophic, with severe phimosis. Histologic analysis revealed dilated lymphatic vessels lined by a discontinuous layer of flat endothelial cells in the papillary dermis and extending down to the reticular dermis. Dilated blood vessels were also present but no cellular abnormalities were identified. A diagnosis of superficial cutaneous lymphatic malformations was made. To the best of our knowledge, this is the first detailed cutaneous histologic investigation in a patient with Hennekam syndrome. We assume that the onset of cutaneous lesions in our patient was likely triggered by a generalized worsening of his lymphedema.