{"entity":{"id":"tumour-differentiation","kind":"term","name":"Tumour differentiation (well / moderately / poorly differentiated)","aka":["well-differentiated","well differentiated","moderately differentiated","poorly differentiated","poorly-differentiated","undifferentiated","dedifferentiated","differentiated thyroid cancer","differentiated"],"tldr":"How much the cancer cells still resemble the normal tissue they came from. Well-differentiated tumours look almost normal and tend to grow slowly; poorly differentiated ones have lost their identity and behave aggressively. It is the basis of grade.","summary":"Pathologists assign differentiation from gland formation, nuclear appearance and mitotic rate; it underlies grading systems such as Gleason (prostate), Nottingham (breast) and WHO grade for neuroendocrine tumours (well-differentiated NETs versus poorly differentiated neuroendocrine carcinomas, which are treated like small-cell cancer). Well-differentiated mucosal gastric cancers qualify for endoscopic resection; poorly differentiated thyroid cancer loses iodine uptake. Dedifferentiation over time (liposarcoma, thyroid, prostate to neuroendocrine) marks transformation to a more aggressive state.","asOf":"2026-09-09","wikipedia":"https://en.wikipedia.org/wiki/Grading_(tumors)","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Grading_(tumors)"}],"tags":[],"related":["gleason-grade-group","adenocarcinoma","dysplasia"],"cancers":["neuroendocrine","thyroid","prostate"],"sections":["diagnostics"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Pathology"},"route":"/terms/tumour-differentiation/","neighbours":{"term":[{"id":"prostate-acinar-adenocarcinoma","kind":"term","name":"Acinar adenocarcinoma of the prostate","route":"/terms/prostate-acinar-adenocarcinoma/"},{"id":"adenocarcinoma","kind":"term","name":"Adenocarcinoma","route":"/terms/adenocarcinoma/"},{"id":"cribriform-prostate-cancer","kind":"term","name":"Cribriform growth pattern in prostate cancer","route":"/terms/cribriform-prostate-cancer/"},{"id":"dysplasia","kind":"term","name":"Dysplasia (pre-cancerous change)","route":"/terms/dysplasia/"},{"id":"gleason-grade-group","kind":"term","name":"Gleason score / Grade Group","route":"/terms/gleason-grade-group/"},{"id":"grade-vs-stage","kind":"term","name":"Grade versus stage","route":"/terms/grade-vs-stage/"},{"id":"histology","kind":"term","name":"Histology","route":"/terms/histology/"},{"id":"keratoacanthoma","kind":"term","name":"Keratoacanthoma: the tumour that may be a squamous cell carcinoma","route":"/terms/keratoacanthoma/"},{"id":"nottingham-grade","kind":"term","name":"Nottingham grade (breast cancer grade 1, 2 and 3)","route":"/terms/nottingham-grade/"},{"id":"bcc-growth-pattern","kind":"term","name":"The growth pattern on a basal cell carcinoma report: nodular, superficial, infiltrative, basosquamous","route":"/terms/bcc-growth-pattern/"},{"id":"cscc-subtype-and-grade","kind":"term","name":"The subtype and grade on a cutaneous squamous cell carcinoma report","route":"/terms/cscc-subtype-and-grade/"},{"id":"who-breast-classification","kind":"term","name":"The WHO classification of breast tumours, and what the 6th edition changed","route":"/terms/who-breast-classification/"},{"id":"ttf1-p40","kind":"term","name":"TTF-1 and p40 (how lung histology is decided)","route":"/terms/ttf1-p40/"}],"cancer":[{"id":"extrapulmonary-nec","kind":"cancer","name":"Extrapulmonary neuroendocrine carcinoma","route":"/cancers/extrapulmonary-nec/"},{"id":"grade-3-net","kind":"cancer","name":"Grade 3 well-differentiated neuroendocrine tumour","route":"/cancers/grade-3-net/"},{"id":"neuroendocrine","kind":"cancer","name":"Neuroendocrine tumours","route":"/cancers/neuroendocrine/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"thyroid","kind":"cancer","name":"Thyroid cancer","route":"/cancers/thyroid/"}],"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}]}}