Cytological features of mandibular actinomycotic osteomyelitis in a cow

The aim of this short communication is to describe the cytopathological features of the actinomycotic osteomyelitis suspected in right mandible of a 30-month-old female Friesian cow. May Grünwald-Giemsa (MGG) stained cytological samples revealed hypercellularity, neutrophils, erythrocytes, osteoclasts, macrophages or epithelioid cells, few lymphocytes and fibroblasts and, at high magnification, microscopic “sulphur granules”. After cytological diagnosis, histopathological examination was not performed, but microbiological investigations confirmed the presence of Actinomyces bovis. The report emphasizes the usefulness of fine needle aspiration biopsy (FNAB), which is a safe, easy, fast, effective, inexpensive and minimally invasive diagnostic technique. FNAB can be considered useful to differentiate actinomycotic lesions from neoplastic disorders of bone.