1. A lesion area extraction apparatus for extracting a lesion area from a medical image, the apparatus comprising: an extraction process recording means for recording a plurality of lesion area extraction processing data generated in advance according to a plurality of types of lesion areas; a report recording means for recording a radiology report which includes a character string having a lesion description character and being related to position information of a lesion area in the medical image; an extraction process determination means for determining, based on the lesion description character provided in the radiology report, one of the plurality of lesion area extraction processing data to be used to extract the lesion area; and an area extraction means for performing the extraction using the determined lesion area extraction processing data and the position information of the lesion area related to the character string.