A Rare Coexistence: Pulmonary Langerhans Cell Histiocytosis and Pulmonary Tuberculosis in a Young Male

Abstract

Pulmonary Langerhans Cell Histiocytosis (LCH) is a rare disorder affecting the lung parenchyma with an unclear underlying cause. The condition is marked by isolated or multiple proliferations of histiocytes, which resemble dendritic Langerhans cells in phenotype. The progression of LCH varies significantly, ranging from isolated eosinophilic granulomas in the bone to widespread involvement of multiple organs. Although rare, LCH has been observed in conjunction with other conditions, like pulmonary tuberculosis. We describe an uncommon case involving a 34-year-old male patient who presented with fever, dry cough, and progressively worsening dyspnea, accompanied by an unintentional weight loss of 15 kg over the preceding 20 days. He was diagnosed with both pulmonary tuberculosis (TB) and Pulmonary Langerhans Cell Histiocytosis (P-LCH). The diagnosis was corroborated by radiological imaging, which displayed multiple nodules and small cysts in the upper and middle lung lobes on both sides, consistent with P-LCH. Additionally, sputum CBNAAT testing confirmed the presence of Mycobacterium tuberculosis.