Fibroadenoma – Wikipedia

Fibroadenoma of the breast is a benign tumor composed of a biplastic proliferation of both stromal and epithelial components. [12] [13] This biplasia can be arranged in two growth patterns: pericanalicular (stromal proliferation around epithelial structures) and intracanalicular (stromal proliferation compressing the epithelial structures into …

https://en.wikipedia.org/wiki/Fibroadenoma