RADIOLOGIC MANIFESTATIONS OF LANGERHANS CELL HISTIOCYTOSIS IN PEDIATRICS

Abstract

PURPOSE: To assess and review the radiologic manifestations of pediatric patients diagnosed with Histiocytosis. METHODS: A total number of 48 biopsy-proven Langerhans Cell Histiocytosis (LCH) patients (<14 years old) were retrospectively reviewed. As one of diagnostic work up, all the selected patients underwent radiologic studies including radiographic bone survey which were reviewed by radiologist for musculoskeletal and respiratory system findings. RESULTS: Lytic bone lesions, lung involvements and generalized osteoporosis were the most common radiologic findings among the patients. 38 of them (79.2%) had bone involvements; skull was involved the most (66.7%), followed by Pelvis (31.3%), Femur (31.3%), Sphenoid (30.0%) and ribs (16.7%). In 10 cases (20.8%) periosteal reaction was seen and 4 cases (8.3%) had metaphyseal lucent band. In the long bones, metaphysis(31.3%) was the most commonly affected, followed by diaphysis (18.8%) and epiphysis (2.0%). One fourth of patients (12 cases) had vertebral involvements. None of these cases had cervical vertebral lesions while in 10 (21.0%) and 7 (14.6%) of them lumbar and thoracic vertebras were involved. Lung involvement was detected in 33 patients (68.8%). The most common involvement patterns were reticulonodular in 30 cases (62.5%), honeycomb with 13 cases (27.1%) and mediastinal widening with 5 cases (10.4%). CONCLUSION: Lytic lesions in flat bones like skull are the most common radiologic manifestation of LCH, followed by reticulonodular pulmonary involvement, as well as generalized osteoporosis. Solitary long bone lesions and isolated lung involvement are not common and must be correlated with clinical condition in cases suspicious of LCH. Keywords : Histiocytosis, Pediatrics, Radiology