Figure 4.

Histomicrographs of representative lesion sections from Fig.2 stained with Hematoxylin and Eosin and showing the i) lesion (L) and lesion border (B) and ii) central portion of the lesions treated at a) 1%; b) 3%; c) 5%; and d) 10% duty cycle. In the border of the a) 1% duty cycle lesion, there were some vacuoles (V) present which was not observed for the 3, 5, or 10% duty cycles. The a) 1% duty cycle resulted in a uniformly homogenized tissue with some nuclear fragments (yellow arrow). With increasing duty cycle, the number of nuclear fragments (yellow arrow) increased and the contents of the lesion became more textured indicating thermal coagulation. Scale bar represents 200 mm. iii) High magnification of Masson’s trichrome stained sections reveal intact fibrillar collagen (F) present in lesions treated with a) 1% duty cycle and b) 3% duty cycle. With the higher duty cycles, the collagen becomes globular (G), with the d) 10% duty cycle having a greater amount of globular collagen than the c) 5% duty cycle. Close to the collagen, small caliber vessels and ducts (yellow arrow head) were present in many of the lesions. Scale bar represents 100 μm.