Primary actinomycosis of breast-A diagnosis on cytology.

Primary actinomycosis of breast is a rare disease with only a few cases reported in the literature. We present a case of a 25-year-old lactating woman with primary actinomycosis of breast which was diagnosed on cytology. The patient presented with lump in left breast with dull aching pain. Fine-needle aspiration cytology smears showed acute suppurative inflammation with presence of fluffy basophilic colonies on Hematoxylin and Eosin staining and branched, Gram positive filamentous bacilli on Gram staining. The bacilli were non-acid fast with 1% Zeihl Neelsen stain. A diagnosis of actinomycosis was suggested on cytology. Histopathological examination revealed an abscess with few Gram positive basophilic granules surrounded by eosinophilic Splendore-Hoeppli material thus confirming the diagnosis of actinomycosis. Meticulous search for microorganisms with the aid of special stains should be done on cytology smears before labeling an inflammatory lesion as nonspecific. Diagn. Cytopathol. 2016;44:693-695. © 2016 Wiley Periodicals, Inc.