Langerhans-cell histiocytosis (LCH) a presentation of two siblings with two different entities.

Langerhans cell histiocytosis (LCH) as a term encompasses eosinophilic granuloma and two clinical syndromes: Letterer-Siwe disease and Hand-Schüller-Christian. All these syndromes seem to represent similar processes in which the proliferating cells have the structural and functional features of Langerhans cells. In reviewing the literature found that this disease does indeed occur in some families more often than would be expected. We present two boys, siblings with LCH in a single family with two different entities (There were no other siblings) and this paper is presented to emphasize the very rare familial occurrence of EG and the other one with Letterer-Siwe disease in our single family. The first patient, first child for consanguineous parents, 15 month boy, was born following an uncomplicated cesarean section, fullterm pregnancy. He developed well on bottle feed. At 13 months of age, he was noted to have a low hemoglobin concentration, mild fever, painful tender swellings and redness over the left lower chest wall a small subcutaneous mass was found. After clinical, radiological and histopathologic review, it was diagnosed as eosinophilic granuloma. Their second child, 6 month boy after a second cesarean section. At 5 month of age he developed a scaly, erythematous rash on his back spread to his shoulders, limbs and upper chest wall. The diagnostic conclusion from the clinical, skin biopsy, histopathology and bone marrow study was histiocytosis X and the diagnosis of Letterer-Siwe disease was established. Many studies listed a number of reported families with a disease which, though not considered as Letterer-Siwe disease by the authors, must certainly belong to the histiocytosis group. Many families reported have had more than one child affected with the generalized form of histiocytosis X. No case did a known relative other than a sibling have a similar disease, one family with known consanguinity, the parents were cousins. No such previous report presented these two rare different entities in two siblings as in our family.