Aspiration biopsy of nodular pseudoangiomatous stromal hyperplasia of the breast: Clinicopathologic correlates in 10 cases

Nodular pseudoangiomatous stromal hyperplasia (PASH) of the breast is rare and often indistinguishable from fibroadenoma, clinically and oil aspiration biopsy smears. We report out-observations in 10 patients with PASH, evaluated by,fine-needle aspiration (FNA) biopsy and core biopsy. We retrospectively reviewed the clinical. radiographic, cytologic, and histologic findings in 10 cases of pure nodular PASH. Ten patients with a presumed clinical and radiologic diagnosis of fibroadenoma underwent aspiration biopsy. The aspiration smears were diagnosed as fibroadenoma (4 cases), cellular fibroadenoma (1 case), schwannoma versus neurofibroma (1 case), fibrocystic change (3 cases; 2 with atypia), and "not specific for a lesion" (1 case). A diagnosis of PASH was not suspected in any case. A discrepant or imprecise cytologic diagnosis and/or the presence of dissociated spindle or epithelial cells, or cellular stromal fragments prompted a surgical excision in 7 of 10 patients (70%). The remaining 3 patients exhibited cytologic features of fibroadenoma and were diagnosed as such; however, surgical excision was recommended. Three patients underwent a subsequent core biopsy, with a diagnosis of PASH being made in 1 patient. FNA biopsy could not discriminate PASH front fibroadenoma in 4 of 10 patients (40%) or suggest a diagnosis of PASH in any case. On retrospective review, the finding of plump, spindle-shaped mesenchymal cells may be a cytologic clue to suggest a diagnosis of PASH. (c) 2005 Wiley-Liss. Inc.