Despite the good prognosis of PAs with AECs, there is no good morphologic consensus or guidelines for how much or what kind of cytologic changes warrant a diagnosis of “atypia,” “dysplasia,” or “carcinoma-in situ.” There is also no consensus on the prognostic significance of AR and/or HER2 expression in PAs of varying morphologies. Here, ERBB2 is linked to in situ carcinoma.