Background: The use of fine needle aspiration cytology (FNAC) for the diagnosis of breast diseases in men has received little attention. We report the cytologic and histologic findings of myofibroblastoma of the breast in a 52-year-old man.
Case: Smears disclosed irregular and cohesive sheets of cells, with ill-defined cytoplasm and oval nuclei containing single nucleoli. The nuclear membrane was frequently grooved, and occasional intranuclear cytoplasmic inclusions (pseudoinclusions) were also found. The background was clean and contained scarce collagenous stroma and fragments of myxoid material. To the best of our knowledge, there have been only seven previous reports of breast myofibroblastoma in which the cytologic features are well documented, and none of them mention the presence of pseudoinclusions.
Conclusion: FNAC could suggest the diagnosis of this distinctly uncommon tumor if evaluated together with the clinical and radiologic findings.