phyllodes tumor (cystosarcoma phyllodes)

Epidemiology: a) most common in middle aged & elderly women b) rare in patients < 20 years of age Pathology: 1) gross appearance a) tumors generally firm & rubbery, but may be gelatinous b) cut surface may have cauliflower appearance c) may be foci of hemorrhage & necrosis (features of malignancy) 2) histopathology a) shares features of fibroadenoma b) prominent intracanalicular pattern c) stromal hypercellularity is most important distinguishing feature 3) metastases after local recurrence most frequently involves the lungs, via blood Clinical manifestations: 1) rapidly enlarging mass may occur, sometimes at the site of a pre-existing, long-standing mass 2) generally larger than fibroadenomas 3) surface projections are often present Laboratory: -> flow cytometry for ploidy & S-phase population may be useful for determining prognosis Differential diagnosis: 1) fibroadenoma 2) benign versus malignant phyllodes tumor Management: 1) resection: a) incomplete resection may account for local recurrence b) axillary dissection NOT indicated 2) prognosis a) generally benign b) more likely to recur locally than fibroadenoma c) in rare cases, may metastasize* d) tumor size does not determine prognosis * transformation to periductal sarcoma

References

Diagnostic Surgical Pathology, 3rd edition, Sternberg SS et al, eds, Lippincott & Williams, 1999, vol 1, pg 366