PMC3919931_01
Sagittal view on T2-weighted magnetic resonance imaging at (A) two and (B) four months after completing treatment for hypopharyngeal carcinoma. A well-defined tumour in the pituitary fossa was revealed in subsequent imaging (arrow).
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Subsequent magnetic resonance imaging (MRI) revealed a well-defined mass at the pituitary fossa that partially obliterated the posterior lobe (Fig. 1).
Gross appearance of the surgical specimen. Grossly, the tumour appeared brown and soft.
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Grossly, the tumour appeared brown and soft (Fig. 2).
Microscopically, the tumour contained small round tumour cells in a solid sheet pattern, with focal tumour necrosis (H&E; magnification, x200).
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Microscopically, it contained small blue round tumour cells in a solid sheet pattern, with focal tumour necrosis (Fig. 3).
Tumour cells revealed a high nucleo-cytoplasmic ratio, hyper-chromatic nuclei, occasional nucleoli and frequent mitoses (H&E; magnification, x400).
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The tumour cells revealed a high nucleo-cytoplasmic ratio, hyperchromatic nuclei, occasional nucleoli and frequent mitoses (Fig. 4).
By immunohistochemistry, the tumour cells were diffusely weak to moderately positive for cytokeratin (A), diffusely positive for cluster of differentiation (CD)117 (magnification, x100), (B) focally positive for CD56 (magnification, x200) and (C) negative for cytokeratin (CK)7, CK20, chromogranin, synaptophysin, CK5/6, p63, S-100 and CD99 (magnification, x200).
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As observed using immunohistochemistry, the tumour cells were diffusely weak to moderately positive for cytokeratin, diffusely positive for cluster of differentiation (CD)117, focally positive for CD56 and negative for cytokeratin (CK)7, CK20, chromogranin, synaptophysin, CK5/6, p63, S-100 and CD99 (Fig. 5).