The Relationship of Pseudoangiomatous Stromal Hyperplasia (PASH)-Like Appearance in Invasive Breast Carcinomas with PASH Areas in Non-Tumoral Breast Parenchyma as Well as on Axillary Lymph Node Involvement

OBJECTIVES: The aim of this study were to determine the relationship of pseudoangiomatous stromal hyperplasia (PASH)-like appearance in invasive breast carcinomas (IBCs) with PASH foci in the non-tumoral breast parenchyma as well as axillary lymph node involvement. METHODS: In this study, 200 consecutive cases with IBC were re-examined. Cases with and without PASH-like appearance in IBC were determined. Each case was assessed regarding the presence of accompanying PASH foci (CD34+, CD31-) in the non-tumoral areas in addition to other clinicopathological parameters. RESULTS: PASH-like appearance within the IBC was present in 22 of the 200 cases (11%) and absent in 178 (89%). The presence of PASH foci in the non-tumoral breast parenchyma was significantly more common in IBC with PASH-like appearance compared to the group without such areas. However, there was no significant difference between the groups regarding other clinicopathological parameters (age, tumor size, nuclear and histological grade, Estrogen receptor/Progesterone receptor status, HER2 status, and Ki-67 proliferation index), lymphovascular invasion (LVI), and axillary lymph node involvement. There was no significant difference between the two groups regarding the histopathological findings observed in the non-tumoral areas. CONCLUSION: PASH-like appearance within IBC was found to be associated with higher rate of PASH foci in the non-tumoral breast parenchyma. However, such cases do not show a difference as regards LVI and axillary lymph node metastasis.