Fine needle aspiration cytology of tubular breast carcinoma and radial scar.

Fine needle aspiration cytology (FNAC) findings in 33 tubular breast carcinomas (TC) and 10 radial scars (RS) were reviewed. In 19 (57%) cases of TC, a categorical diagnosis of malignancy could be made. Four (12%) TC, all containing myoepithelial cells, were misdiagnosed as benign. None of the RS was misinterpreted as malignant on FNAC. All RS smears contained myoepithelial cells. Although RS shared some of the cytologic features of TC, the lack of conspicuous nucleoli and pleomorphism prevented a false-positive diagnosis. Tubular angular structures, considered to be a characteristic feature of TC, may also occur in RS. Cellularity was poorer in RS than TC. The FNA yield obtained when attempting to aspirate small TC and RS lesions may originate in adjacent breast lesions and give a misleading cytologic picture. The occurrence of myoepithelial cells and/or lack of dissociation are not unequivocal benign signs in FNA smears; such findings do occur in TC. Finally, the difficulties that may be encountered in the diagnosis of TC and RS by frozen section are briefly discussed. Radiology often helped in establishing a diagnosis of malignancy in TC but did not help in ruling out malignancy in RS. A teamwork approach to the diagnosis and management of these lesions is recommended.