ABSTRACT
<p><b>OBJECTIVE</b>To observe the clinical features of Langerhans cell histiocytosis (LCH), and to improve its early diagnosis and treatment.</p><p><b>METHODS</b>Retrospective analysis of 160 cases of adult LCH from pathology department, West China Hospital of Sichuan University and Union Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 1992 to December 2013 were performed, and their clinical features were analyzed.</p><p><b>RESULTS</b>Of 160 cases, there were 110 male and 50 female, the male to female ratio was 2.2:1. The mean age was 35(18-73) years. There were total 222 lesion sites, including 172(77.5%) osteal lesions, followed by 13(5.8%) lymph nodes and 8(3.6%) oral cavity lesions. The other involved organs were skin(5, 2.2%), liver(5, 2.2%), fossa orbitalis(4, 1.8%), lungs(4, 1.8%), sternoclavicular joint(3, 1.4%), gastrointestinal(2, 0.9%), ear(2, 0.9%), and thyroid (2, 0.9%), adrenal gland (1, 0.5%) and sublingual gland (1, 0.5%). Of 160 cases, 150 (93.8%) had one organ involved while 10 (6.2%) had two or more organs involved. Clinically, 77 cases (48.1%) were misdiagnosed as bone tumors (28 cases, including giant cell tumor, fibrous dysplasia, chondroblastoma, osteoblastoma and osteosarcoma), bone tuberculosis (13 cases), meningioma(9 cases), bone cysts (5 cases), chronic osteomyelitis (5 cases) and diabetes insipidus (5 cases) , skin (4 cases) diseases malignant lymphoma (4 cases), chronic skin ulcers (4 cases), chronic otitis media (1 case), lung (1 case) and oral cancer (1 case).</p><p><b>CONCLUSION</b>In this group of the adult cases, the ratio of the male patients is higher. Adult LCH occurs predominantly in bone and presents mainly as unisystem single-focal disease, but multi-organ lesion and skin involvement are lower than that reported in the literatures. Just as LCH in children, adult LCH is also easy to be misdiagnosed. We should raise awareness of the disease and pathological examination is helpful for early diagnosis.</p>