Figure 1.

Representative images of photodynamic detection-positive cases. (a–c) Canine thyroid carcinoma. The red fluorescence at 635 nm is evident in the cancerous lesions but not in the necrotic tumor lesions. Scale bar: 2 cm. (d–f) Inguinal lymph node metastasis in a mammary gland tumor. The red fluorescence at 635 nm is evident in the metastatic lesions but not in the non-metastatic regions. Scale bar: 3 mm. (a,d) White light images; (b,e) fluorescence light images; (c,f) hematoxylin and eosin-stained images.