Case 40 Answer
A large well-defined lobular mass with prominent arterial flow is present at the site of palpable abnormality. This most likely (and was) a Giant Fibroadenoma. A breast bud should look like normal breast tissue. This patient is young for a phylloides tumor. Ductal carcinoma has not been reported in a 14 year old. In the rare case of cancer in a child, it would be more likely a rhabdo or other childhood malignancy.
Giant Fibroadenomas (also called Juvenile fibroadenomas) are usually rapidly-growing. If left alone, they can get large enough to impinge on the development of the normal breast bud. They are usually excised.
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