The parents didn’t care when it was small at first, but as it grew larger and larger, they took him to the local hospital for an examination, which revealed bone defects and lesions in the ribs, thoracic vertebrae, and other bones. After a pathological biopsy, he was diagnosed with “Langerhans cell histiocytosis”. At the same time, an 8-month-old child, Fei Fei, who had repeated fever and rash, came to our hematology department and found anemia, enlarged liver and spleen, and lymph nodes, and was also diagnosed with “Langerhans cell histiocytosis” through further examination. So, what exactly is this disease, and why is it diagnosed as the same disease with different clinical manifestations? Langerhans cellhistiocytosis (LCH) is a group of diseases of unknown etiology and diverse clinical manifestations, mostly in pediatric patients, more in males than in females, and divided into three types according to the main clinical manifestations: Letterer-Siwedisease (LS), Hand-Schuller-Christian disease (HSC), and Langerhans cellhistiocytosis (LCH). Schuller-Christian disease (HSC) and eosinophilic granuloma ofboneEGB, but the clinical manifestations of each type can overlap with each other and an intermediate type emerges, whose common histological features are Langerhans cell proliferation and infiltration with eosinophils, monocytes- The common histological features are proliferation and infiltration of Langerhans cells, accompanied by different degrees of proliferation of eosinophils, monocytes-macrophages and lymphocytes. The clinical manifestations include fever, rash, enlarged liver and spleen lymph nodes, respiratory symptoms, anemia, otitis media, diarrhea, and malnutrition. Bone destruction can involve any bone, the skull being the most common, and there are also mixed and single organ damage types. Therefore, any unexplained fever, rash, anemia, pus in the ear canal, recurrent lung infections, enlarged liver and spleen lymph nodes, bulging eyes, urinary collapse, cranial defects, and head masses should be suspected of the disease, and the diagnosis requires a combination of clinical manifestations, imaging, and pathology. Since the disease is variable and mild, the treatment plan should depend on the specific clinical situation. The main method is chemotherapy, commonly used drugs are prednisone, vincristine, etoposide, cyclophosphamide, etc. Other immunotherapy, radiation therapy, etc. Local EGB can be surgically scraped. Langerhans cell histiocytic hyperplasia is not a malignant tumor and can be remitted and controlled through treatment. Its prognosis is related to the age of onset, the number of organs involved, damage to organ function and initial treatment response. The Department of Hematology of the Third Affiliated Hospital of Zheng University has rich treatment experience in this area and a medical team with first-class technology. Through the careful treatment by Dr. Wang Xige, chief physician of the Department of Hematology of our hospital, and Dr. Zhao Xuelian, deputy chief physician and Dr. Liang Yu, attending physician, Dongdong’s condition gradually stabilized without further development, and little Feifei’s temperature gradually stabilized, the rash subsided, the liver and spleen all shrunk, and the children’s faces showed bright smiles again .