| CASE |
| Malignant phyllodes tumor |
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| HISTORY |
| A 61 year old woman with a breast mass |
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| MICROSCOPIC DETAILS |
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Fig. 2 |
Fig. 3 |
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| Fig. 1- Low power magnification view of the tumor with marked stromal proliferation. |
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| Fig. 2- Low power view of an area of stromal overgrowth showing hypercellular stroma with nuclear pleomorphism. |
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| Fig. 3- Higher power view of the stromal area highlighting the atypia of the stromal cells, which range in appearance from round to spindled, and which show some mitotic activity. |
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| DIAGNOSIS |
| Malignant phyllodes tumor |
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| DISCUSSION |
| This tumor consists of markedly hypercellular stroma with a leaf-like growth pattern. High power shows severe cellular atypia and pleomorphism with multiple mitoses (more than 10 per 1 HPF). The epithelial component appears benign with focal ductal hyperplasia. The presence of invasive margins cannot be assessed with certainty in this core biopsy. However the present criteria are sufficient for the diagnosis of malignant phyllodes tumor. Complete excision with clean margins should be performed. |
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| REFERENCES |
| Upon request |
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