Figure 4. Histologic findings in group III (LITT alone). (A) 24 hours after treatment, the tumor cells partially loosened from the cell unit but the tumor structure is mostly preserved (bar = 2 μm, H&E). (B, D) BrdU incorporation of the tumor cells was negative in the application zone and the central zone of the hyperthermically damaged area of all samples. Samples show BrdU incorporation of the tumor cells in the reference zone 24 hours (B) and 14 days (D) after treatment (bar = 5 μm, BrdU histochemistry). (C) Microscopic section 14 days after interstitial laser application showing tumor progression in the reference zone (bar = 2 μm, H&E).