Diagnosis of diffuse malignant infiltration of lung (lymphangitic carcinomatosis) by percutaneous fine-needle aspiration biopsy.

The diagnosis of diffuse malignant infiltration of lung is often made with certainty only by open lung biopsy or at autopsy. However, the clinical presentation and radiological examination are often sufficiently characteristic to suggest the diagnosis. Percutaneous fine-needle aspiration biopsy (PFNAB) has been reserved mainly for the diagnosis of focal lesions of lung and has been reported not to be useful in the diagnosis of diffuse lung disease, especially when the latter is mainly interstitial. We report 15 patients with radiologically diagnosed diffuse interstitial infiltration of lung, 13 of whom had lymphangitic carcinomatosis either on clinical follow-up, cytological or pathological examination. Cytology by percutaneous fine-needle aspiration biopsy was positive for malignant cells in 11 of the 13 patients. We propose that PFNAB be used early in investigation when the clinical and radiological findings suggest that a patient has diffuse malignant interstitial lung infiltration.