MICROSCOPIC DESCRIPTION: 1&2. Sections show a moderately cellular tumour, together with fragments of bone. The tumour is composed of cells with abundant clear to vacuolated cytoplasm set within myxoid stromal material. Tumour cells contain hyperchromatic, angulated nuclei with bland chromatin and inconspicuous nucleoli. No necrosis or mitosis are seen. There are areas of haemorrhage with haemosiderin laden macrophages and immature woven bone, consistent with remodelling. Immunohistochemical results show tumour cells stain: CKAE1/3+, EMA+ and S100+; consistent with chordoma.
DIAGNOSIS: 1&2. Brain, posterior fossa lesion: Chordoma.
Images and report courtesy from the Royal Melbourne Hospital Pathology Department.