case_images: PMC3643374_01
case_images: (a) Cellular smear showing loose clusters of cells with preponderance of histiocytes with few of them showing kidney shaped nucleus (arrow), alongwith neutrophils (N), lymphocytes (L) in the background. (Pap, x400); (b) Cells showing pseudoinclusion (arrow) (Pap, x400); (c) Binucleated histiocyte (arrow) (Giemsa, x400)
case_images: JCytol-30-81-g001.jpg
case_images: PMC3643374_01_JCytol-30-81-g001.jpg
case_images: F1
case_images: These histiocytes were binucleate, multinucleate with abundant dense cytoplasm and eccentric vesicular nuclei [Figure 1a-c]. The nuclei showed characteristic intranuclear pseudoinclusions, prominent nuclear indentations and grooves (with a kidney or coffee bean appearance) [Figure 1b]. The background showed lymphocytes, neutrophils and few eosinophils [Figure 1a].
case_images: (a) Biopsy showing variable histiocytes with mononucleate, binucleate and multinucleate cells amidst lymphocytes and polymorphs (H and E, x400); (b) Immunostaining with S100 showed diffuse positivity in the atypical histicytes (IHC, x100)
case_images: JCytol-30-81-g002.jpg
case_images: PMC3643374_01_JCytol-30-81-g002.jpg
case_images: F2
case_images: There was no necrosis, and no mitosis [Figure 2a]. On immunohistochemical staining, S-100 and CD1a were diffusely positive in all the atypical histiocytes [Figure 2b].