Transthoracic aspiration biopsy. Occurrence of non-neoplastic cells in biopsies from malignant and non-malignant lesions.

In the search for a possible distinction between false and true negative biopsies, an analysis of the distribution of the non-neoplastic cells has been performed in 100 randomized transthoracic aspiration biopsies in so many histologically verified cases. Aspiration biopsies from malignant lesions often contain many giant cells, alveolar epithelial cells, and mast cells, but a significant differences was only found for the mast cells. A negative biopsy containing many inflammatory cells and mast cells and showing a pronounced degree of necrosis may represent a chronic obstructive pneumonitis, and such a finding should always prompt further investigation.