Loading
Poorly differentiated chordoma is a rare, aggressive form of chordoma of children and young adults, mostly at the base of the skull or in the neck, defined by loss of the SMARCB1 (INI1) protein. It grows faster and spreads more than ordinary chordoma, and the SMARCB1 loss makes it a candidate for drugs that block EZH2, though surgery and radiotherapy remain the treatment.
The WHO bone classification recognises poorly differentiated chordoma as a subtype defined by brachyury expression with loss of SMARCB1 (INI1), first characterised as a distinct molecular entity with dismal prognosis (Acta Neuropathologica 2016). In the 19-patient series, tumours arose in the skull base and clivus (53 percent), cervical spine (32 percent) and sacrum or coccyx (16 percent), were composed of sheets of epithelioid cells rather than the physaliphorous cells of conventional chordoma, and had worse survival than the other subtypes (Modern Pathology 2018).
How it differs from its parent: age (children rather than adults in their fifties and sixties), the SMARCB1 deletion that groups it biologically with atypical teratoid/rhabdoid tumour and epithelioid sarcoma, and a much shorter survival.
How common: no incidence figure; 19 cases at one referral centre in 27 years (Modern Pathology 2018).
Treatment: maximal safe resection and proton or photon radiotherapy as on the chordoma page; systemic therapy has no standard, and EZH2 inhibition (tazemetostat, approved for SMARCB1-deficient epithelioid sarcoma) is the rational agent under study for SMARCB1-deficient tumours.
Very rare and mostly paediatric: the largest series holds 19 patients diagnosed at a median age of 11 (range 1 to 29) over 1990 to 2017 (Modern Pathology 2018).
Bone sarcomas favour the fast-growing ends of long bones (osteosarcoma) or the shaft (Ewing), soft tissue sarcomas the deep muscle compartments; spread is through the blood to the lungs, rarely via lymph nodes.
Lymph node spread is rare (except epithelioid, synovial, clear cell and rhabdomyosarcoma); sarcomas go through the blood to the lungs.
Same organ: Adamantinoma of bone, Dedifferentiated chordoma, Desmoplastic small round cell tumour, Leiomyosarcoma, Liposarcoma, Synovial sarcoma, Sarcomas (soft tissue, bone, GIST), Osteosarcoma, Ewing sarcoma, Rhabdomyosarcoma, Chordoma, Desmoid tumour, Tenosynovial giant cell tumour (TGCT), Epithelioid sarcoma, Vascular tumours (angiosarcoma, epithelioid haemangioendothelioma, kaposiform haemangioendothelioma), Chondrosarcoma, Angiosarcoma, Undifferentiated pleomorphic sarcoma (UPS), Myxofibrosarcoma, Alveolar soft part sarcoma, Perivascular epithelioid cell tumour (PEComa), Epithelioid haemangioendothelioma, Malignant peripheral nerve sheath tumour (MPNST), Retroperitoneal sarcoma, Soft tissue sarcoma of the extremity (localised and advanced)
Maximal safe resection and proton radiotherapy as on the chordoma page; EZH2 inhibition under study for SMARCB1-deficient tumours.
Country and place are remembered in this browser only. A postcode is sent to OpenStreetMap's Nominatim service to find coordinates when you press the button; nothing else leaves your device.
Query for this cancer: (TITLE:"Poorly differentiated chordoma" OR ABSTRACT:"Poorly differentiated chordoma" OR TITLE:"SMARCB1-deficient" OR ABSTRACT:"SMARCB1-deficient" OR TITLE:"SMARCB1-deficient chordoma" OR ABSTRACT:"SMARCB1-deficient chordoma" OR TITLE:"INI1-negative chordoma" OR ABSTRACT:"INI1-negative chordoma" OR TITLE:"Paediatric poorly differentiated chordoma" OR ABSTRACT:"Paediatric poorly differentiated chordoma") AND (treatment OR therapy OR trial OR survival OR diagnosis). Results are unfiltered search hits about Poorly differentiated chordoma (SMARCB1-deficient), not a curated reading list.
The targets of this cancer's medicines and the ones linked to it directly.
Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record.
One section per setting: the options named, what each is for, the trials behind them, the recorded trade-offs and the questions to ask.
Newly diagnosed? Read the first 60 days with Poorly differentiated chordoma, then print the one-page appointment sheet with room for the answers.
Print this page for your appointment (your browser's print command). These prompts are for discussion; your clinical team knows your case.
Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record.
Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked.