Atypical endometrial hyperplasia diagnosed by hysteroscopic photodynamic diagnosis using 5-aminolevulinic acid

Endometrial cancer is diagnosed by endometrial biopsy, imaging and hysteroscopy, but it is sometimes difficult to find small lesions. 5-aminolevulinic acid (5ALA) forms protoporphyrin IX, which accumulates in tumors and fluoresces upon light irradiation. 5ALA is used for photodynamic diagnosis (PDD) for detecting malignant diseases. A 60-year-old female was suspected to have endometrial cancer by magnetic resonance imaging. Endometrial biopsy was performed repeatedly, but no malignant lesion was detected. We performed hysteroscopic 5ALA-PDD and could detect a small lesion. The lesion was excised and diagnosed as atypical endometrial hyperplasia histopathologically. This is the first report that showed hysteroscopic 5ALA-PDD can contribute to diagnosis of early-stage neoplastic lesion in the uterine cavity.