Intraductal carcinoma of the prostate in the absence of high‐grade invasive carcinoma represents a molecularly distinct type of in situ carcinoma enriched with oncogenic driver mutations

Intraductal carcinoma of the prostate (IDC‐P) most often appears associated with high‐grade invasive prostate carcinoma (PCa), where it is believed to represent retrograde spread. However, IDC‐P rarely occurs as an isolated finding at radical prostatectomy or with concurrent low‐grade (Grade Group 1) invasive carcinoma. We hypothesized that isolated IDC‐P (iIDC‐P) in these unusual cases may represent a distinct in situ lesion and molecularly...