noun
primary lesion
Medical term for the original site of a disease, especially cancer, from which metastasis may occur. Often contrasted with 転移巣 (metastatic lesion).
See also: 転移巣
医師は原発巣の切除を勧めた。
The doctor recommended removal of the primary lesion.
転移
Metastasis was found, but the primary lesion has not yet been identified.