NODULAR PSEUDOANGIOMATOUS STROMAL HYPERPLASIA OF THE BREAST - CYTOLOGIC FEATURES

OBJECTIVE: To define and discuss the cytologic findings in six eases o f nodular pseudoangiomatous stromal hyperplasia (PASH) of the breast. STUDY DESIGN: Retrospective evaluation of the medical records, cytolog ic and histologic material from six patients with palpable mammary PAS H. Cases in which PASH was associated with other predominant mammary l esions were not included in the study. RESULTS: A total of six patient s with histologically proven PASH underwent aspiration in nine occasio ns (three patients studied twice). Clinically, five patients were diag nosed as having fibroadenoma or another benign lesion, and in one pati ent carcinoma was suspected. In two patients, mammography disclosed ra pid growth of the lesion. Seven aspirations, performed on five patient s, were diagnosed as fibroadenoma (n = 5) or fibroadenomatous lesion ( n = 2). An eighth aspiration was cystic and reported as fibrocystic di sease. The last case mas erroneously diagnosed as suspicious for carci noma. Even after revision, the cytologic similarities of PASH with fib roadenoma were remarkable. Most smears were less cellular than those o f conventional fibroadenomas. Epithelial clusters showed variable size , with a predominance of medium to small groups. Stromal elements were minimal or absent. Background cellularity was composed of round to ov al naked nuclei and others with spindle shapes. Occasional epithelial clusters showed cellular dissociation and slight atypia. CONCLUSION: D ue to the absence of specific cytologic features and similarities to f ibroadenoma, a precise diagnosis of PASH cannot be made on cytologic m aterial. However, the majority of cases can be diagnosed correctly as benign, allowing appropiate treatment.