Langerhans Cell Histiocytosis in a Non-Smoking Adult Patient: Clinical Considerations in a Rare Presentation

Langerhans cell histiocytosis (LCH) is a rare histiocytic disorder characterized by the proliferation of cells of the mononuclear phagocytic system. In addition, they predominantly affect children, with peak incidence between the ages of 1 and 4. However, it is not unusual for them to be diagnosed in adults. In particular, pulmonary involvement occurs in approximately 10% of LCH cases. The diagnosis is confirmed by histology. Treatment is adapted according to the spread of LCH. A 32-year-old female patient presented with a productive cough and exertional dyspnea on June 18, 2023. With a history of Nodular Sclerosis Hodgkin Lymphoma (NSHL) diagnosed on April 28, 2023, without treatment. Family history: mother alive with non-Hodgkin lymphoma treated with chemotherapy. A computed axial tomography (CT) scan was performed, reporting a right lung mass and adenopathy in the bilateral cervical supraclavicular region, bilateral axillary region predominantly on the right, bilateral mediastinal and inguinal regions. Denies a history of smoking and alcoholism. Biopsy and immunohistochemistry result: S100, CD1a, CD68 positive; cytokeratin and EMA negative) confirmed pulmonary LCH. Start treatment with MACOP-B, cytarabine and methotrexate. The patient showed disease progression and died from multiple organ failure. LCH occurs almost exclusively in smokers or former smokers, being considerably less frequent in non-smokers. In addition, it has been associated with Hodgkin’s lymphoma and following treatment with chemotherapy and radiotherapy. The definitive diagnosis is established by biopsy of the lesion associated with immunohistochemical techniques (CD1a+ and CD207+). PLCH remains an extremely rare condition in this population, which means that it is rarely considered in the diagnostic workup