Chordoma, adamantinoma and marrow tumours in bone
- Lesion
Chordoma grows from notochord remnants at the skull base and sacrum; adamantinoma favours the tibia; myeloma and lymphoma also present as bone lesions.
What it is
Some important bone tumours fit none of the main matrix groups. Chordoma is a malignant tumour of notochordal differentiation that arises along the axial skeleton, mostly the sacrum and the clivus at the skull base, and grows slowly but invades locally. Adamantinoma is a low-grade biphasic epithelial and fibro-osseous tumour almost always in the tibia. Haematolymphoid tumours, especially plasma cell myeloma, lymphoma and Langerhans cell histiocytosis, often present as lytic bone lesions and are diagnosed by the pathologist on bone biopsy.
Structure
- Chordoma: lobules of cords and nests of large cells with clear, bubbly cytoplasm (physaliphorous cells) in a blue myxoid matrix.
- Adamantinoma: basaloid, squamoid or spindle epithelial nests within a bland fibrous and osteofibrous stroma.
- Langerhans cell histiocytosis: Langerhans cells mixed with many eosinophils (eosinophilic granuloma).
- Myeloma: marrow replaced by sheets of plasma cells, eccentric nuclei with clock-face chromatin.
Step by step
- Notochord remnants persist along the axial skeleton after development.
- Gain or duplication of brachyury, a notochord transcription factor, helps drive transformation.
- Chordoma grows slowly, destroying the sacrum or clivus and compressing nerves.
- It recurs locally after incomplete removal and metastasizes late.
Markers
- Brachyury (chordoma)
- Keratin (chordoma, adamantinoma)
- CD1a and langerin (Langerhans cell histiocytosis)
- CD138 and kappa or lambda (myeloma)
Clinical notes
- Sacral chordoma causes low back pain, constipation and bladder symptoms; clival chordoma causes headache and cranial nerve palsies, especially diplopia.
- Any new lytic lesion in an adult over 40: think first of metastasis and myeloma.
- Child with a lytic skull lesion and bone pain: Langerhans cell histiocytosis is in the differential.
Test yourself
Think of the answer, then tap the question to see it.
Where does chordoma arise?
Along the axial skeleton, mainly the sacrum and the clivus.
What are physaliphorous cells?
Large cells with bubbly, vacuolated cytoplasm characteristic of chordoma.
Which nuclear marker supports chordoma?
Brachyury.
Which bone is almost always affected by adamantinoma?
The tibia.
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Chordoma: MedlinePlus Genetics (MedlinePlus, US National Library of Medicine, 2025); Multiple myeloma: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025).
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Representative model, for educational purposes only.