**6.2 Immunoistochemistry**

The expression of PSA, panCK, and Ki67 in non-treated regions of the prostate is marginally stronger than in the HIFU region. CK8 is strongly expressed in luminal cells of normal and malignant glands outside the HIFU lesion, but pre-existing and malignant epithelium within the HIFU lesion does not express CK8, regardless of the histomorphological changes in conventional light microscopy.

The hyperplastic epithelium at the periphery of the HIFU lesions reacts with the basal cell antibody 34βE12.

In summary, we can say that prostate glandular epithelium after HIFU treatment reacts with antibodies to pancytokeratin, prostate specific antigen (PSA), and Ki67, but does not express cytokeratin 8, which is indicative of severe cellular damage.

### **6.3 Electron microscopy**

Ultrastructural examination after HIFU reveals disintegration of cellular membranes and cytoplasmic organelles consistent with cell necrosis.

Electron microscopy is not routinely performed. When performed, it confirms submicroscopical cellular damage in the centre of the HIFU lesion.

Fig. 8. Granulation tissue and fibrosis 6 months after HIFU treatment.

express cytokeratin 8, which is indicative of severe cellular damage.

submicroscopical cellular damage in the centre of the HIFU lesion.

cytoplasmic organelles consistent with cell necrosis.

The expression of PSA, panCK, and Ki67 in non-treated regions of the prostate is marginally stronger than in the HIFU region. CK8 is strongly expressed in luminal cells of normal and malignant glands outside the HIFU lesion, but pre-existing and malignant epithelium within the HIFU lesion does not express CK8, regardless of the histomorphological changes

The hyperplastic epithelium at the periphery of the HIFU lesions reacts with the basal cell

In summary, we can say that prostate glandular epithelium after HIFU treatment reacts with antibodies to pancytokeratin, prostate specific antigen (PSA), and Ki67, but does not

Ultrastructural examination after HIFU reveals disintegration of cellular membranes and

Electron microscopy is not routinely performed. When performed, it confirms

**6.2 Immunoistochemistry** 

antibody 34βE12.

**6.3 Electron microscopy** 

in conventional light microscopy.

Electron microscopy is capable to demonstrate cell necrosis also in areas that show no apparent morphological cell necrosis by conventional light microscopy.

Treated areas lack nuclear membranes, but show a fine chromatin pattern that is clumped at the periphery of the nuclei, and conspicuous nucleoli.

The cytoplasm contain some vacuoles, but organelle structures and cell membranes are not generally identified.
