title: "Missed" diagnoses of phyllodes tumor on breast biopsy: pathologic clues to its recognition.
abstract: Fibroadenoma and phyllodes tumors of the breast exhibit a continuum of pathologic features. We examined phyllodes tumors initially called fibroadenoma for features that may accurately classify the tumor as phyllodes tumor on the first biopsy specimen. The phyllodes tumors initially called fibroadenoma for features that may accurately classify the tumor as phyllodes tumors on the first biopsy specimen are examined. Fifteen patients with phyllodes tumors were studied, initially called FA or another term short of PT. These tumors were compared with 16 true fibroadenomas, all with needle-core biopsy followed by excision. Resected phyllodes tumors were larger on average than fibroadenoma, 6.8 cm (range = 1.7-16.2 cm) versus 2.6 cm (range = 1.0-4.8 cm). In needle-core biopsy cases, sampling was limited, even in large breast masses. p53 and cleaved caspase-3 were noncontributory. Ki-67 showed higher proliferation indices in phyllodes tumors versus fibroadenoma (4.8% vs 0.6%). Features suggesting phyllodes tumors include tissue fragmentation, increased stromal cellularity especially around glands, stromal overgrowth, and increased mitoses. Increased sampling of a large tumor will likely yield more correct diagnoses.
authors.affiliation: Department of Pathology, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
authors.forename: Sophia
authors.initials: S
authors.lastname: Yohe
authors.forename: I-Tien
authors.initials: IT
authors.lastname: Yeh
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery; D002467:Cell Nucleus / Q000737:chemistry / Q000473:pathology; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D018226:Fibroadenoma / Q000175:diagnosis; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D003557:Phyllodes Tumor / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen