Changes in the bronchial epithelium between the second and the fifth day after the previous biopsy

BACKGROUND: Regenerative changes may be found in bronchia, in the area of previous biopsy. Superficial epithelium in the injured area proliferates, migrates and differentiates, primarily towards the squamous cells, and then towards cup-shaped, i.e. column cells with cilia. Regenerative changes can be misinterpreted for epidermoid carcinoma. The highest level of similarity of regenerative changes and epidermoid carcinoma is between the second and the fifth day after the previous biopsy. MATERIALS AND METHODS: In this research, we used 66 biopsy samples. They were classified into two groups (33 re-biopsied between the second and the fifth day and 33 with diagnostically confirmed epidermoid carcinoma). In both groups, the same morphological parameters were monitored and then tested by means of z test with 5% tolerance (α=0.05). RESULTS: Morphological changes that are typical for epithelium in regeneration, are the following: fibrin (z=4.41; P=0.000), granulocytes (z=4.79; P=0.000), granulocytes in epithelium (z=6.92; P=0.000), infiltration into granulation tissue. Tumor changes are the following: presence of mononuclear cells (z=-3.63; P=0.0003), diskeratosis (z=-4.29; P=0.000), nuclear polymorphism (z=-4.22; P=0.000), hyperchromatism (z=-3.83; P=0.000), and infiltration into connective tissue (z=-5.76; P=0.000). Changes, which are useless for differentiation of regeneration and carcinoma, are the following: nucleoli (z=-1.77; P=0.0763), multinuclear cells (z=0.25; P=0.8041), mitoses (z=-1.44; P=0.151), interruption of the basal membrane (z=1.07; P=0.2866). CONCLUSION: Presence of squamous epithelium located in fibrin and/or granulation tissue saturated with granulocytes is a morphological characteristic of regenerative epithelium. Presence of squamous epithelium, with symptoms of severe polymorphism of nuclei, with hyperchromatism, with monocellular diskeratosis, located in cellular tissue saturated with mononuclear cells , is a characteristic of malignant epithelium.