图示乳腺分叶状肿瘤。它们源于小叶间质，但不象纤维腺瘤，它们不常见而且大的多。它们分级低因此很少转移。它们比纤维腺瘤细胞更丰富。 A phyllodes tumor of the breast is shown here. They arise from interlobular stroma, but unlike fibroadenomas are not common and are much larger. They are low-grade neoplasms that rarely metastasize. They are more cellular than fibroadenomas. Projections of stroma into the ducts create the leaf-like pattern for which these tumors are named (from the Greek word phyllodes meaning leaf-like).