Enzyme histochemical detection of cell viability in ablation area of thyroid nodules at 6 months after microwave ablation / 第二军医大学学报

ABSTRACT

Objective To explore the cell viability in the ablation area of thyroid nodules at 6 months after microwave ablation by enzyme histochemical staining. Methods Twenty-four ablation areas of thyroid nodules were selected from 20 patients who underwent histopathological assessment of the ablation area by core needle biopsy at 6 months after microwave ablation between Dec. 2017 and Sep. 2018. Core needle biopsy was performed at the central and marginal regions of the ablation area with a cutting biopsy needle. The specimens were obtained and placed in liquid nitrogen to make frozen sections. Enzyme histochemical staining was used to detect the activities of succinate dehydrogenase (SDH) and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), and the difference of cell morphology and histological structure was compared with H-E staining results. Results The specimens of the central and marginal regions of 24 ablation areas were successfully obtained. The histochemical staining of SDH and NADPH-d in the central region of ablation area had good consistency, and the negative rates were both 95.83% (23/24). The histochemical staining of SDH and NADPH-d in the marginal region of ablation area also had good consistency, and the negative rates were both 91.67% (22/24). H-E staining of 23 central regions and 22 marginal regions showed pink amorphous mass of necrosis. H-E staining of 1 central region and 2 marginal regions showed partly necrotic and fibrous tissue hyperplasia. The location of fibrous tissue hyperplasia was consistent with the location of the positive region of enzyme histochemical staining. Conclusion At 6 months after microwave ablation, the tissue in the ablation area of thyroid nodules is consistent with coagulative necrosis, and is still inactivated. SDH or NADPH-d enzyme histochemical staining combined with H-E staining can objectively evaluate the old ablation area.