Spindle Cell Variant of Ameloblastic Carcinoma: Another Example in a Japanese Male

Figure 3

Immunohistochemistry. Tumor cells are diffusely immunoreactive for p40 widely spreading beneath the eroded mucosa (a). Spindle cells in a fascicular arrangement also indicate p63 immunoreactivity (b). Spindle cells are also immunoreactive for CK5/6 (c). A better differentiated area including the portion reminiscent of enamel pulp shows a positive reaction for CK19 (d). Spindle cells show a patchy reaction for aSMA (e). Brisk mitotic figures are evident in the spindle cell fascicle (red circle). Similarly, immunoreactivity for calponin is observed (f). Almost all tumor cells are labelled with p53 (g), and the vast majority with Ki-67 (h).

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