[Cytology of various rare benign tumors of the breast].

The authors describe the cytological appearances of three rare benign mammary tumors (granular cell myoblastoma, sebaceous cyst and fibrous histiocytoma), and warn the clinician against over-optimism when presented with a benign cytologic diagnosis. In fact, the proportion of cases in which carcinoma is confused with a benign tumour varies from 3 to 5% according to statistics. They analyse the various causes responsible for the "false benign" diagnosis. The author's opinion is that one can only arrive at the cytological diagnosis of benignity as part of a group of investigations. Final diagnosis must depend upon a histological examination.