[Verse 1]
Lauren split it two ways — intestinal creeps along the Correa cascade
H. pylori, atrophy, metaplasia, dysplasia, then malignant grade
Diffuse type loses E-cadherin, CDH1 mutation at the core
Hereditary diffuse gastric cancer knocking on the family door
Signet ring cells float like wreckage, stomach walls turn thick and stiff
Borrmann four is linitis plastica, scirrhous spread across the cliff
HER2 amplified, MSI status, EBV and PD-L1 CPS
Molecular subtypes stratify who gets which targeted regress
[Chorus]
Lauren, Borrmann, Correa cascade — intestinal or diffuse
KIT and PDGFRA in the GIST — mitotic rate's the fuse
Chromosomal instability, MSI, CIMP pathway too
KRAS, NRAS, BRAF mutations telling you what drugs to use
Adenoma-carcinoma sequence — Haggitt levels one to four
Lynch, FAP, MUTYH, Peutz-Jeghers — know your syndromes to the core
[Verse 2]
GISTs arise from Cajal cells, the gut's electrical grid
KIT exon eleven mutates — most common thing it did
Size and mitotic rate and site determine risk tier placement
Gastric low-mitotic versus jejunal — different hazard statement
Neuroendocrine tumours graded by Ki-67 proliferation
Type one gastric NETs from hypergastrinaemia — ECL cell foundation
Type three sporadic, aggressive, metastatic inclination
Small bowel NETs in ileum, carcinoid syndrome — diarrhoea and flushing sensation
Appendiceal under two centimetres — simple resection clears the case
Rectal NETs submucosal, EUS to measure depth and space
[Chorus]
Lauren, Borrmann, Correa cascade — intestinal or diffuse
KIT and PDGFRA in the GIST — mitotic rate's the fuse
Chromosomal instability, MSI, CIMP pathway too
KRAS, NRAS, BRAF mutations telling you what drugs to use
Adenoma-carcinoma sequence — Haggitt levels one to four
Lynch, FAP, MUTYH, Peutz-Jeghers — know your syndromes to the core
[Verse 3]
Colorectal polyps: tubular, villous, tubulovillous adenoma
Serrated sessile lesion, TSA — each a different chromosoma
Malignant polyp — Haggitt levels through the stalk into the wall
Kikuchi's submucosal thirds tell surgeons when resection's called
APC lost in FAP, a thousand polyps carpet every fold
AFAP a gentler phenotype, attenuated but still bold
Lynch syndrome — MLH1, MSH2, MSH6, PMS2
Mismatch repair deficiency, microsatellite instability's the clue
Serrated polyposis — BRAF, CIMP, the methylation route
Peutz-Jeghers — STK11 mutation, hamartomas throughout
[Bridge]
MALT lymphoma — H. pylori drives the antigenic flame
Eradicate the bug and watch the tumour shrink in shame
Mantle cell hits small bowel, immunoproliferative disease
LAMN spreads mucin through the peritoneum — PCI to appease
Anal squamous cell carcinoma — HPV sixteen and eighteen
AIN grades the intraepithelial — catch it while it's lean
Goblet cell adenocarcinoma blurs the appendix line
Pseudomyxoma peritonei — HIPEC the design