To improve the clinical understanding of Pulmonary Langerhans cell histiocytosis, The clinical data of one adult patient diagnosed and treated in our hospital were retrospectively collected and analyzed.

The clinical data of the patient with Pulmonary Langerhans cell histiocytosis were retrospectively collected and the related literature was reviewed.

The empiric antiinfective therapy did not improve symptoms in the patient with restricted mouth opening, chest tightness, chest pain, and chest CT suggesting lung masses. Percutaneous lung puncture biopsy was performed several times outside the hospital, but the diagnosis was not clear. After being admitted to our hospital, the patient underwent a percutaneous lung puncture biopsy while empiric anti-infection was performed again, and the diagnosis was finally confirmed as Pulmonary Langerhans cell histiocytosis.

The PLCH of adult is a rare abnormal histiocytic proliferative disease in tissues mainly characterized by diffuse proliferation and infiltration of Langerhans cells. Its clinical symptoms and signs vary greatly, and this disease is easy to be misdiagnosed. Multiple tissue biopsies are required when necessary, and immunohistochemical tests are crucial for definite diagnosis. The treatment of adult PLCH should be strictly individualized according to the severity of the disease. Meanwhile, regular follow-up should be conducted to dynamically evaluate the prognosis and timely adjust the treatment plan according to the condition.