Lung carcinoma with diffuse cystic lesions misdiagnosed as pulmonary langerhans cell histocytosis: a case report.

BACKGROUND: Cystic airspace is an uncommon imaging manifestation involved in non-small lung cancer (NSCLC). Diffuse cystic lesion is even rarer as pulmonary manifestation of NSCLC. In the present study, we reported a rare case of NSCLC associated with progressive diffusion of cystic lesions misdiagnosed as Pulmonary langerhans cell histocytosis (PLCH), finally diagnosed by transbronchial cryobiopsy (TBCB). CASE PRESENTATION: A 52-year-old woman was admitted to our hospital due to cough and dyspnea. High-resolution computed tomography (HRCT) presented diffuse cystic shadow mostly, concomitantly with nodular densities in bilateral lungs. A lung biopsy revealed poorly differentiated adenocarcinoma with vascular tumor emboli. The epidermal growth factor receptor (EGFR) mutation on exon 18 (G719X, G719) was detected by mutation test. The patient received treatment of tyrosine kinase inhibitor (afatinib). CONCLUSIONS: Diffuse cystic lesion can be a rare manifestation of lung cancer. It was important to improve the recognition of diffuse cystic lung diseases to avoid misdiagnosis.