PMC2995998_01
Firm, nonulcerated reddish-blue tumor in the maxilla
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On the anterior region of the maxilla, a firm nonulcerated reddish-blue tumor of about 4 cm x 3 cm was seen to be protruding through the lips and covered by the intact mucosa [Figure 1].
Computed tomography scan showing lobed extensive tumor of the anterior maxilla and central hypodense area
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The computed tomography (CT) scans of the head and neck region showed a tumor in the anterior maxilla region with a central hypodense area [Figure 2].
Gross specimen showing a well-circumscribed soft mass
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The cut surface was grayish-white in color with black pigmented areas [Figure 3].
Fibrovascular stroma with nests and clusters of cells arranged in an alveolar pattern (H and E, x4)
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The central part of the alveoli were made up of small and round cells with little cytoplasm and dark nuclei whereas the peripheral part comprised of cuboidal, flattened epitheloid cells containing melanin pigment in the cytoplasm [Figures 4 and 5].
Central part of the alveoli made up of small and round cells with little cytoplasm and dark nuclei whereas the peripheral part comprised of cuboidal, flattened epitheloid cells (H and E, x4)
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The central part of the alveoli were made up of small and round cells with little cytoplasm and dark nuclei whereas the peripheral part comprised of cuboidal, flattened epitheloid cells containing melanin pigment in the cytoplasm [Figures 4 and 5].
Peripheral melanin-containing epitheloid cells showing positivity (Masson' Fontana, x4)
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Masson Fontana staining showed positivity for melanin in peripheral epitheloid cells [Figure 6].
IHC staining showing HMB-45 positivity in peripheral epitheloid cells
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Immunohistochemical analysis revealed positive staining for HMB-45 in the melanin-containing peripheral polygonal cells and for synaptophysin in the small neuroblast-like cells [Figures 7 and 8].
IHC staining showing synaptophysin positivity in central small neuroblast-like cells (x10)
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Immunohistochemical analysis revealed positive staining for HMB-45 in the melanin-containing peripheral polygonal cells and for synaptophysin in the small neuroblast-like cells [Figures 7 and 8].