Notochordal Chordoma

Epidemiology:

• Males:Females = 1.8:1
• > 30y

Common sites:

• always in the midline
• sacrum (60%)
• extension is almost always into presacral space
• clivus, spheno-occipital/nasal (25%)
• spine

Gross features:

• solitary
• 5 to 15cm usually
• soft
• mucogelatinous to friable
• lobulated
• mucoid
• grey
• hemorrhagic
• extension out of bone into adjacent soft tissue
• X-ray:
• Lytic
• Destructive
• Shards of ony detritus
• Intratumour calcification may be present

Histologic features:

• lobulated:
• lobules of tumour separated by bands of fibrosis
• sheets, cords, or single cells floating in an abundant myxoid stroma
• variability from area to area
• small round cells:
• abundant pale vacuolated cytoplasm (“physaliphorous cells”)
• mild to moderate nuclear atypia
• epithelial or spindled
• mitoses infrequent
• chondroid variant (may have better prognosis):
• areas mimicking hyaline or myxoid cartilage
• “dedifferentiated” chordoma/sarcomatoid chordoma:
• chordoma associated with a high-grade sarcoma

Immunophenotype:

Marker:

Sensitivity:

Specificity:

S-100

Pan-keratin 

LMWK

EMA

Molecular features:

• hypodiploid often
• loss of chromosomes 3, 4, 10, 13
• LOH at 1p36
• most commonly deleted segments:
• 1p31-pter, 3p21-pter, 3q21-qter, 9p24-pter, 17q11-qter
• gains:
• 5q, 7q, 20

Other features:

· low to intermediate grade malignant

o may metastasize to lung, bone, soft tissue, nodes, skin

· spheno-occipital lesion may cause:

o compression of a cranial nerve (ocular most common)

o compression and destruction of the pituitary leading to endocrine disturbances

o cerebello-pontine angle symptomatology

References:

• WHO Soft tissue and Bone Tumours (2002)