Stromal cell architecture

Periductal stromal tumor was initially described by Burga and Tavassoli as a distinct entity from phyllodes tumors that was histologically identical but lacked the intracanalicular or leaflike pattern.Like phyllodes tumors, however, the stromal cells express CDS 4, and thus some have proposed that they are best regarded as a phyllodes tumor variant that lacks the classic leaflike architecture rather than a distinct entity. 

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