Fig. 3

Macroscopic and pathologic images of a 75-year-old man with extramammary Paget’s disease (EMPD). a External appearance before boron neutron capture therapy (BNCT): a pruritic, painful and persistent erythematous lesion (arrows) was on the penis and scrotum. Penile atrophy was due to long-term hormonal administration for prostate cancer. b Microscopic findings: histopathology was diagnostic for EMPD, as evidenced by large, round, vacuolated, infiltrating intraepithelial malignant cells. The basal membrane was partially unclear. c External appearance after BNCT: BNCT delivered an absorbed dose of 8.7 Gy-Eq to the normal skin and 23 Gy-Eq to the tumor. He had a complete response with depigmentation of the lesion, and no severe adverse event (such as ulceration), and was alive and well without evidence of recurrence or adverse effects at 6.9 years after BNCT