[Harlequin fetus--a case report].

A one-day-old male premature baby was born to a G4P4 mother with the gestation age of 30 weeks. His birth weight was 2000 gm. He was noted to be covered with a thick, armor-like skin which is split by deep fissures and makes the feature of Ectropion and eclabium. His nose was flattened, only the nostrils were visible, and the external ears were underdeveloped. The hands and feet appeared to be swollen and crumpled. The genital organ was covered with thick fissured skin and it was impossible to distinguish sex by external appearance. Three days after delivery, the patient died of respiratory distress. He was found normal through general laboratory and chromosome study. However, dermatohistology showed hyperkeratosis, focal parakeratosis and hypogranulosis. Pathology showed PDA (patent ductus arteriosus), enlarged thymus and congestion of internal organs. Its etiology and pathogenesis somehow remain unknown. We hereby reported this harlequin fetus, the most severe type of lamellar ichthyosis, and discussed its incidence, pathogenesis, pathohistology, prognosis and the recent development in treatment.