Intraductal

Intraductal is an anatomical and clinical descriptor used in medicine to denote processes, lesions, or growths that occur within the lumen of a duct. Ducts are tubular channels that transport fluids such as milk, bile, pancreatic juice, or saliva, and intraductal pathology is characterized by confinement to the ductal system without invasion through the duct wall into surrounding tissue.

In breast pathology, several entities are described as intraductal. Intraductal carcinoma in situ (DCIS) is a non-invasive malignant proliferation confined to the breast ducts. Intraductal papilloma is a benign ductal lesion featuring fibrovascular cores with papillary fronds that project into the duct lumen; it can cause nipple discharge.

In the pancreas, intraductal papillary mucinous neoplasm (IPMN) arises within the pancreatic ducts and can produce mucin; IPMNs range from benign to invasive adenocarcinoma, and management is guided by features such as mural nodules, dilation, and cytology.

In the prostate, intraductal carcinoma of the prostate (IDC-P) refers to a pattern of high-grade cancerous growth within prostatic ducts that is often associated with a more aggressive, advanced disease when found alongside invasive carcinoma.

In general, distinguishing intraductal lesions from invasive ones is important for prognosis and treatment planning. Diagnostic methods include imaging, cytology, and histopathology. Common examples of intraductal conditions include DCIS of the breast, intraductal papilloma, IPMN of the pancreas, and IDC-P in prostate cancer.