{"entity":{"id":"paper-basturk-baltimore-consensus-precursor-lesions-ajsp-2015","kind":"paper","name":"A revised classification system and recommendations from the Baltimore consensus meeting for neoplastic precursor lesions in the pancreas","aka":[],"tldr":"An international panel simplified precursor grading to low grade and high grade, reserving high grade for carcinoma in situ, and set rules for margins, small intraductal lesions and simple mucinous cysts.","summary":"International experts revised the 2004 recommendations for assessing and reporting precursor lesions of the pancreas, including PanIN, IPMN, mucinous cystic neoplasm and others. A two-tiered system (low versus high grade) is proposed for all precursor lesions, with former PanIN-2 and intermediate-grade neoplasms categorised as low grade and high-grade dysplasia reserved for carcinoma in situ-type lesions. PanIN of any grade at a resection margin has no prognostic implication. Intraductal lesions of 0.5 to 1 cm may be large PanINs or small IPMNs, with 'incipient IPMN' reserved for those with intestinal or oncocytic papillae or GNAS mutations. Distance between IPMN and invasive carcinoma should be measured to assess concomitant versus associated status. 'Intraductal spread of invasive carcinoma' and 'simple mucinous cyst' are defined.","asOf":"2026-09-24","links":[{"label":"Basturk et al., Am J Surg Pathol 2015: Baltimore consensus, two-tier grading of precursor lesions","url":"https://doi.org/10.1097/PAS.0000000000000533"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/26559377/"}],"tags":[],"related":[],"cancers":["pancreatic","ipmn-cystic-precursors"],"sections":[],"technologies":[],"targets":["gnas"],"drugs":[],"companies":[],"institutions":["mskcc","johns-hopkins"],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"journal":"American Journal of Surgical Pathology","year":2015,"doi":"10.1097/PAS.0000000000000533","pmid":"26559377","authors":"Basturk O, Hong SM, Wood LD, et al.","paperType":"guideline","findings":["Two-tier grading (low versus high) for all pancreatic precursor lesions.","PanIN at a margin carries no prognostic implication; GNAS mutation defines incipient IPMN."],"whatItMeans":"The reporting standard behind every modern precursor study and the reason a pathology report now says low or high grade rather than PanIN-2.","caveats":["Consensus, not evidence from outcome data.","Clinical significance of dysplasia at a margin in non-invasive IPMN is unresolved."],"changedPractice":true},"route":"/key-papers/paper-basturk-baltimore-consensus-precursor-lesions-ajsp-2015/","neighbours":{"cancer":[{"id":"ipmn-cystic-precursors","kind":"cancer","name":"Intraductal papillary mucinous neoplasm and other pancreatic cystic precursors","route":"/cancers/ipmn-cystic-precursors/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"}],"target":[{"id":"gnas","kind":"target","name":"GNAS","route":"/targets/gnas/"}],"institution":[{"id":"johns-hopkins","kind":"institution","name":"Johns Hopkins Hospital / Sidney Kimmel Comprehensive Cancer Center","route":"/institutions/johns-hopkins/"},{"id":"mskcc","kind":"institution","name":"Memorial Sloan Kettering Cancer Center","route":"/institutions/mskcc/"}]}}