chordoma

Introduction

tumor from notochord remnants, occur along pathway of primitive notochord extending from dorsum sellae to coccyx.

Epidemiology

• 1-4% of malignant bone tumors
• involves axial spine
  • sacral 60%
  • spheno-occipital/nasal 25%
  • cervical 10%
  • thoracolumbar 5%

Pathology

• derived from notochordal remnants
• extradural multilobulated tumors
• cordlike rows of physaliphorous cells (highly vacuolated)
• mucoid or myxoid background
• cartilage formation may be seen (chondroid chordoma)
• cellularity, pleomorphism, mitoses not predictive of tumor aggressiveness
• subtypes:
  • chondroid chordoma
  • dedifferentiated chordoma

Immunophenotype

• S100 +
• pan-keratin (CAM5.2, AE1/AE3) +
• low molecular weight cytokeratins +
• EMA +
• N-cadherin +
• E-cadherin variable

Genetics

• a protein T gene duplication is involved in susceptibility to the development of chordoma

Clinical manifestations

• low to intermediate grade malignant tumor
• chordomas occur along the length of the spinal axis, predominantly in the sphenooccipital, vertebral & sacrococcygeal regions
• they are characterized by slow growth, local destruction of bone, extension into adjacent soft tissues & rarely, distant metastases

Radiology

• solitary central lytic destructive lesions of axial skeleton
• hypo or isointense on T-1 weighted MRI
• high signal intensity on T-2 weighted MRI

Differential diagnosis

• basal meningioma
• schwannoma
• nasopharyngeal carcinoma
• pituitary adenoma
• craniopharyngioma
• chondroid neoplasm: Chondrosarcomas tend to stain negatively with antibodies for cytokeratins and cadherins. Chondrosarcoma & chondroid chordoma stain positively for S100 and vimentin. Occasional S100 + cells persist in spindle cell or dedifferentiated areas of chordoma

More general terms

• embryonal neoplasm

Patient information

chordoma patient information

Database

• OMIM: https://mirror.omim.org/entry/215400