Prostatic duct adenocarcinoma, characterized by pseudostratified columnar epithelium, has historically been considered invasive carcinoma, although it may commonly have an intraductal component. Usual (acinar) intraductal carcinoma of the prostate (IDC-P) is a noninvasive high-risk lesion typically associated with high-grade, high-stage prostate cancer. Whereas there have been rare biopsy studies of pure acinar IDC-P or IDC-P associated with only low-grade carcinoma, there have been no analogous series of IDC-P with cribriform or papillary ductal morphology on biopsy unassociated with invasive high-grade carcinoma. We identified 14 patients with biopsies showing IDC-P with ductal morphology, defined as prostatic duct adenocarcinoma confined to glands/ducts with immunohistochemically proven retention of basal cells. Our series includes 12 patients with pure IDC-P and 2 patients with concurrent low-volume Grade Group 1 invasive cancer in unassociated cores. Three patients underwent radical prostatectomy: 2/3 had high-grade cancer in their resection specimen (Grade Group 3, Grade Group 5), including 1 with advanced stage and nodal metastases; 1/3 had Grade Group 1 organ-confined carcinoma and spatially distinct IDC-P with ductal morphology. Five men had only follow-up biopsies: 2/5 had cancer (Grade Group 2, Grade Group 4); 1/5 had IDC-P (on 2 repeat biopsies); and 2/5 had benign transurethral resection of the prostate. In all 5 cases with invasive cancer, the invasive portion was comprised purely of acinar morphology; no invasive ductal component was identified. Five patients did not have follow-up biopsies and were treated with radiation therapy±androgen deprivation. One patient had no follow-up information. In an analogous situation to acinar IDC-P, we propose that rarely there is a precursor form of ductal adenocarcinoma that can exist without concurrent invasive high-grade carcinoma and propose the term “IDC-P with ductal morphology,” consistent with the terminology for acinar prostate adenocarcinoma. Until more evidence is accumulated, we recommend reporting and treating patients with IDC-P with ductal morphology in a manner analogous to those with acinar IDC-P. As with pure IDC-P with acinar morphology, we would also recommend not grading pure IDC-P with ductal morphology. Finally, we propose a new addition to the diagnostic criteria of IDC-P to include intraductal lesions with ductal morphology consisting of papillary fronds or cribriform lesions lined by cytologically atypical pseudostratified epithelium.

前列腺管腺癌以假复层柱状上皮为特征，历来被认为是浸润性癌，尽管它通常可能具有导管内成分。前列腺常见（腺泡）导管内癌 (IDC-P) 是一种非侵袭性高风险病变，通常与高级别、高阶段前列腺癌相关。尽管对纯腺泡 IDC-P 或仅与低级别癌相关的 IDC-P 进行了罕见的活检研究，但还没有类似的 IDC-P 系列在活检中具有筛状或乳头状导管形态，与浸润性高级别癌无关。 。我们确定了 14 名患者，其活检显示具有导管形态的 IDC-P，定义为局限于腺体/导管的前列腺导管腺癌，经免疫组织化学证明有基底细胞保留。我们的系列包括 12 名纯 IDC-P 患者和 2 名在无关核心中并发低容量 1 级浸润性癌症的患者。3例患者接受根治性前列腺切除术：2/3的切除标本中含有高级别癌症（3级、5级），其中1例为晚期和淋巴结转移；1/3 患有 1 级器官局限性癌和空间上不同的 IDC-P，具有导管形态。5 名男性仅进行了后续活检：2/5 患有癌症（2 级组、4 级组）；1/5 有 IDC-P（2 次重复活检）；2/5 接受良性经尿道前列腺切除术。在所有 5 例浸润性癌症病例中，浸润性部分仅由腺泡形态组成；未发现侵入性导管成分。五名患者没有进行后续活检，并接受了放射治疗±雄激素剥夺治疗。一名患者没有随访信息。在与腺泡 IDC-P 类似的情况下，我们提出很少有导管腺癌的前体形式可以在没有并发侵袭性高级别癌的情况下存在，并提出术语“具有导管形态的 IDC-P”，与术语一致腺泡前列腺腺癌。在积累更多证据之前，我们建议以类似于腺泡 IDC-P 患者的方式报告和治疗具有导管形态的 IDC-P 患者。与具有腺泡形态的纯 IDC-P 一样，我们也建议不要对具有导管形态的纯 IDC-P 进行分级。最后，我们提出了 IDC-P 诊断标准的新补充，包括导管内病变，其导管形态由乳头状叶状或排列有细胞学非典型假复层上皮的筛状病变组成。