Introduction: Kikuchi-Fujimoto disease (KFD) may have an autoimmune etiology and some cases have been associated with silicone breast implants. Cytomorphologic features of the disease have been well characterized by fine-needle aspiration of lymph nodes. They are so specific as to permit a precise cytologic diagnosis. Cytologic features have not been reported in fluid specimens. Case: A 33-year-old female presented with a unilateral periprosthetic silicone breast seroma. The fluid was drained, and cytological analysis revealed numerous lymphocytes with no neutrophils, karyorrhectic nuclear debris, and peculiar histiocytes with eccentrically located nuclei showing a crescentic shape. Many of those histiocytes showed intracellular apoptotic debris. Conclusion: A Kikuchi disease-like inflammatory reaction is possible not only in axillary and cervical lymph nodes of patients with silicone breast implants but also in breast seromas. There is still not enough evidence to establish if there is an association between KFD and breast implants. A detailed cytologic examination of periprosthetic silicone breast seromas may help answer this question. In any case, pathologists must be aware of this possibility. Cytologic features are characteristic enough to permit differentiation from breast implant-associated anaplastic large-cell lymphoma.