Cytologic features of tubular adenocarcinoma of the breast by aspiration biopsy

Tubular adenocarcinoma is an invasive mammary adenocarcinoma associated with an excellent prognosis and a low incidence of axillary metastases. However, identification of tubular adenocarcinoma by fine-needle aspiration (FNA) biopsy has proven difficult. One hundred five patients with documented "pure" tubular adenocarcinoma were diagnosed at Tisch Hospital from August of 1992 to December of 1998. Twenty-one of these patients had an FNA before excision. We reviewed the smears of these cases and compared them with cases of fibroadenoma and fibrocystic change to identify criteria for diagnosis. Moderately to highly cellular smears with angular cellular clusters with sharp borders and oval cells outlining these clusters, dispersed single cells with minimal atypia, and the absence or paucity of dispersed, bare oval nuclei in the background were features that suggest a diagnosis of tubular adenocarcinoma in our study. Attention to these features in combination with appropriate mammographic findings should preclude a false-negative diagnosis in the majority of cases of tubular adenocarcinoma diagnosed by aspiration biopsy. We point to the presence of the peripheral perpendicular cells in the characteristic tubular arrays as an important clue to the diagnosis of tubular adenocarcinoma. Diagn. Cytopathol. 2001;25:311-315. (C) 2001 Wiley-Liss, Inc.