[Blueberry Muffin Baby and Langerhans' congenital cell histiocytosis].

BACKGROUND: Blueberry Muffin Baby is a rare neonatal cutaneous syndrome for purpuric lesions reflective of extramedullary hematopoiesis. Many causes are known, examples are congenital infections, malignancy and hematologic disorders. Langerhans' cell histiocytosis is a clonal proliferation of dendritic histiocytes. This has very rarely been associated with a Blueberry Muffin Baby presentation. CASE REPORT: We report the case of a newborn presenting with Blueberry Muffin Baby syndrome related to congenital Langherans' cell histiocytosis. At birth, he had multiple purpuric lesions on the trunk, limbs and face. Skin biopsy showed a dermal proliferation of histiocytes staining positive for S100 and CD1a. Chest and bone radiographs, and abdominal ultrasound were normal. Skin lesions have resolved in 8 weeks, the patient is in complete remission at 18 months of follow-up. DISCUSSION: A Blueberry Muffin Baby syndrome may reveal neonatal Langerhans' histiocytosis.