Langerhans Cell Histiocytosis
Publication Date: 2004-06-16
2/19/04 - No abnormality.
CT: A large lytic expansile lesion of the medial portion of the left clavicle is seen with an associated soft tissue mass. There are multiple enlarged lymph nodes in the superior mediastinum, some of which contain calcifications.
Ewing sarcoma, lymphoma, leukemia, metastatic disease, infection (osteomyelitis). However, the bone lesions have many radiographic appearances and other more benign bone tumors can have a similar appearance.
Langerhans cell histiocytosis (LCH) is a disease group characterized by an abnormal proliferation of Langerhans cell histiocytes. Historically, LCH was divided into several different disorders, including histiocytosis X, Letterer-Siwe disease, Hand-Schuller-Christian disease and eosinophilic granuloma. LCH manifests itself focally or systemically. The etiology remains unknown. Boys are affected about twice as often as girls. The disorder is rare in non-Caucasian patients. The disease process causes a broad spectrum of pathologic changes.
The course ranges from benign to malignant. In patients with disseminated disease, the symptons of weakness, weight loss, anorexia, fever, irritability, lethargy, diarrhea may reflect direct involvement of organs. Patients with monostotic involvement maybe totally asymptomatic. Skeletal involvement is most common radiographic abnormality in LCH. The osseous findings are dependent on the phase of the disease and may mimic infection, benign neoplasm, and malignant neoplasm. The extensive distribution of reticuloendothelial cells accounts for the numerous sites of bony involvement. Skull, followed by ribs, pelvis and scapula are the most common sites of skeletal involvement in LCH. LCH may involve extraskeletal lesions in mediastinum, pulmonary parenchyma, pleura, gastrointestinal tract, liver, spleen, and central nervous system. Thymic calcifications can be found in children with LCH.
Therapy for LCH varies with extent of the disease. It may involve observation without intervention, intraosseous steroid administration, low-dose radiation, or chemotherapy. The prognosis for patients with skeletal disease without organ dysfunction is excellent.
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- Heller, G.D., Haller, J.O., Berdon, W.E., Sane, S., Kleinman, P.K., PUNCTATE THYMIC CALCIFICATION IN INFANTS WITH UNTREATED LANGERHANS' CELL HISTIOCYTOSIS: REPORT OF FOUR NEW CASES, Pediatric Radiology, 1999, 29:813-815.