Cytologic preparations reveal hypercellular smears featuring a prominent dual cell population of numerous polymorphonuclear neutrophils and abundant large, lipid-laden macrophages (gitter cells) with characteristic foamy cytoplasm and eccentric nuclei. The background displays extensive liquefactive necrosis, marked by free lipid vacuoles from myelin breakdown, amorphous proteinaceous material, and cellular debris. No cytologically malignant astrocytes, atypical pleomorphic cells, or tissue fragments indicative of a primary or metastatic neoplasm are identified.
Brain abscess.
Two unstained smears were submitted and pap stained.
Brain abscess, aspiration cytology: