Organ schematics
16 organ systems covering 63 cancers, drawn as rotating wireframes in the site's style. Each shows where the cancer's subtypes begin (the marked subsites) and the lymph node stations it drains to, which is what staging scans, sentinel node biopsies and radiotherapy fields are built around.
Breast
Most cancers start in the ducts and drain first to the axillary nodes, which is why the armpit is checked and a sentinel node is sampled.
- Ducts (most cancers start here)Basal-like 1 (BL1, DDR-deficient, platinum/PARP-sensitive) · Basal-like 2 (BL2, growth-factor signalling) · Mesenchymal / claudin-low (EMT, stem-like, chemoresistant) · Luminal androgen receptor (LAR, AR+, PIK3CA-mutant) · HER2-low TNBC (~35%, eligible for T-DXd)
- Lobules (lobular carcinoma)
- Upper outer quadrant (commonest site)
- Nipple-areola
- axillary level I
- axillary level II-III
- internal mammary
- supraclavicular
Same organ: HR-positive / HER2-negative breast cancer, HER2-positive breast cancer
Lungs, pleura and mediastinum
Central tumours arise in the large airways, peripheral ones in the alveoli; both drain to hilar then mediastinal nodes, and the pleural lining is a separate cancer site.
- Central airways (squamous, small-cell)Squamous · Squamous cell carcinoma (~25-30%)
- Periphery (adenocarcinoma)Adenocarcinoma · EGFR-mutant · ALK-rearranged · KRAS-mutant · PD-L1-high · Adenocarcinoma (~50%) · EGFR-mutant (exon 19 del, L858R, exon 20 ins, uncommon) · ROS1-rearranged · KRAS G12C and non-G12C · BRAF V600E · MET exon 14 skipping / MET-amplified · RET-fusion · HER2-mutant · NTRK-fusion · Driver-negative PD-L1-high (TPS ≥50%) · Driver-negative PD-L1-low/negative
- Apex (Pancoast)
- Pleura (mesothelioma)
- Thymus (anterior mediastinum)Adenocarcinoma · Adenocarcinoma (~50%) · Squamous cell carcinoma (~25-30%)
- hilar (N1)
- mediastinal (N2)
- supraclavicular (N3)
Same organ: Small-cell lung cancer, Mesothelioma, Thymoma and thymic carcinoma
Colon, rectum, anus and appendix
Right-sided tumours behave differently from left-sided and rectal ones; the colon drains along its mesenteric vessels, the rectum into the mesorectum and pelvic side wall.
- Right colon (MSI-high, BRAF commoner)Mismatch-repair deficient / MSI-high (~15% localised, ~5% metastatic) · Lynch syndrome (hereditary dMMR, ~3%) · BRAF V600E (~8-10%, right-sided, poor prognosis) · Left-sided vs right-sided (embryologic origin drives biology) · Consensus molecular subtypes CMS1-4
- Left colon and sigmoidChromosomal instability / APC-KRAS-TP53 pathway (~80%) · KRAS-mutant (~45%; G12C ~3-4%, G12D ~13%) · HER2-amplified (~3-5%, RAS wild-type, left-sided) · Left-sided vs right-sided (embryologic origin drives biology)
- RectumRectal vs colon (different local therapy)
- Anal canal (HPV squamous)
- Appendix
- pericolic
- mesenteric root
- para-aortic
- mesorectal
- lateral pelvic and inguinal (anal)
Same organ: Anal cancer (squamous cell carcinoma), Appendiceal cancer and pseudomyxoma peritonei
Oesophagus and stomach
Squamous cancers sit in the upper and middle oesophagus, adenocarcinomas at the junction and in the stomach; the stomach wall also gives rise to GIST from its pacemaker cells.
- Upper and middle oesophagus (squamous)
- Lower oesophagus and junction (adenocarcinoma)GEJ tumours by Siewert type
- Cardia and fundus
- Body (diffuse or intestinal type)Intestinal type (Lauren; H. pylori-associated, HER2-enriched) · Diffuse / signet-ring type (CDH1, peritoneal spread, poor prognosis) · TCGA: EBV-positive (~9%, PD-L1 high, IO-responsive) · TCGA: MSI-high (~20% localised, ~5% advanced) · TCGA: genomically stable (diffuse, RHOA/CLDN18-ARHGAP fusions) · TCGA: chromosomal instability (HER2, EGFR, MET amplification) · HER2-positive (~15-20%) · CLDN18.2-positive ≥75% (~38%) · Hereditary diffuse gastric cancer (germline CDH1)
- Antrum and pylorusIntestinal type (Lauren; H. pylori-associated, HER2-enriched)
- Muscle wall (GIST)
- perigastric (greater and lesser curve)
- coeliac and hepatic
- mediastinal
- cervical (upper oesophagus)
Same organ: Oesophageal cancer, Gastrointestinal stromal tumour (GIST)
Pancreas and bile ducts
Most pancreatic cancers arise in the head next to the bile duct, which is why jaundice is the presenting sign; bile duct cancers are named by where along the tree they sit.
- Pancreatic head (most PDAC)Classical (GATA6-high, better prognosis, more chemosensitive) · Basal-like / squamous (GATA6-low, poor prognosis) · KRAS-wild-type (~10%; NRG1, NTRK, ALK, BRAF fusions; MSI-H) · Germline-driven (BRCA2, PALB2, ATM, CDKN2A, STK11)
- Body and tail
- Ampulla
- Islets (pancreatic NET)Pancreatic neuroendocrine tumours (a different disease; see neuroendocrine)
- Intrahepatic ducts
- Perihilar (Klatskin)
- Distal bile duct
- Gallbladder
- peripancreatic
- hepatic hilar
- coeliac and superior mesenteric
Same organ: Biliary tract cancer (cholangiocarcinoma), Neuroendocrine tumours
Hepatocellular carcinoma grows in a cirrhotic liver and spreads first inside it and into the portal vein, so staging depends on liver function and vascular invasion as much as on size.
- Right lobe (segments V-VIII)Viral (HBV, HCV) HCC · Alcohol-related HCC · MASLD/MASH-related HCC (often non-cirrhotic) · Fibrolamellar carcinoma (young adults, DNAJB1-PRKACA fusion)
- Left lobe (segments II-IV)
- Portal vein (macrovascular invasion)
- Capsule and diaphragm surface
Prostate
About three quarters of cancers arise in the peripheral zone at the back of the gland, the part a finger or a biopsy needle reaches; drainage is to the obturator and iliac nodes.
- Peripheral zone (most cancers)Localised: low / favourable-intermediate / unfavourable-intermediate / high risk (NCCN) · Non-metastatic castration-resistant (nmCRPC) · Metastatic hormone-sensitive (mHSPC; FDA 2026 term 'androgen pathway modulation-naive or -sensitive'), de novo vs recurrent, high vs low volume (CHAARTED) · Metastatic castration-resistant (mCRPC) · HRR-mutant (~20-25% of mCRPC; BRCA2 most actionable) · Treatment-emergent neuroendocrine prostate cancer (~15-20% of late mCRPC)
- Transition zone (BPH)
- Ducts (ductal, intraductal, neuroendocrine)Treatment-emergent neuroendocrine prostate cancer (~15-20% of late mCRPC) · Ductal and intraductal / cribriform variants (aggressive)
- Seminal vesicle (T3b)
- obturator
- internal iliac
- external iliac
- presacral
Kidneys, adrenals, ureters and bladder
Renal cell carcinoma comes from the kidney's filtering cortex, urothelial cancer from the lining of the collecting system and bladder, and the adrenal on top hosts cortical and medullary (neuroblastoma) tumours.
- Renal cortex (RCC)Molecular: luminal-papillary (FGFR3-altered), luminal-infiltrated, basal/squamous, neuroendocrine-like · Variant histologies (squamous, micropapillary, plasmacytoid, sarcomatoid, small-cell)
- Renal pelvis and ureter (upper tract urothelial)Upper-tract urothelial carcinoma (renal pelvis, ureter; ~5-10%)
- Bladder lining (non-muscle-invasive)Non-muscle-invasive (Ta, T1, CIS; ~75%) · Upper-tract urothelial carcinoma (renal pelvis, ureter; ~5-10%) · Molecular: luminal-papillary (FGFR3-altered), luminal-infiltrated, basal/squamous, neuroendocrine-like · Variant histologies (squamous, micropapillary, plasmacytoid, sarcomatoid, small-cell)
- Bladder muscle wall (muscle-invasive)Non-muscle-invasive (Ta, T1, CIS; ~75%) · Muscle-invasive (T2-T4; ~25%) · Molecular: luminal-papillary (FGFR3-altered), luminal-infiltrated, basal/squamous, neuroendocrine-like · Variant histologies (squamous, micropapillary, plasmacytoid, sarcomatoid, small-cell)
- Adrenal cortex
- Adrenal medulla and sympathetic chain (neuroblastoma)
- Developing kidney (Wilms tumour)
- renal hilar
- para-aortic and paracaval
- obturator and iliac (bladder)
Same organ: Renal cell carcinoma, Wilms tumour (nephroblastoma), Neuroblastoma (paediatric), Adrenocortical carcinoma
Uterus, cervix, ovaries, tubes and vulva
Most high-grade ovarian cancers begin at the tip of the fallopian tube; endometrial cancer lines the uterus, cervical cancer starts at the transformation zone; each drains to a different node group.
- Fallopian tube fimbria (origin of high-grade serous)High-grade serous carcinoma (~70%; TP53-mutant, tubal origin) · Low-grade serous carcinoma (~5%; KRAS/BRAF, ER+, chemoresistant) · Clear-cell carcinoma (~10%; ARID1A, PIK3CA; platinum-resistant; higher in East Asia)
- Ovary (other histologies, germ cell)Low-grade serous carcinoma (~5%; KRAS/BRAF, ER+, chemoresistant) · Endometrioid carcinoma (~10%; often with endometriosis; CTNNB1, PTEN, MMR) · Mucinous carcinoma (~3%; KRAS, HER2 amplification; often gastrointestinal-like)
- EndometriumHigh-grade serous carcinoma (~70%; TP53-mutant, tubal origin) · Low-grade serous carcinoma (~5%; KRAS/BRAF, ER+, chemoresistant) · Endometrioid carcinoma (~10%; often with endometriosis; CTNNB1, PTEN, MMR) · Mucinous carcinoma (~3%; KRAS, HER2 amplification; often gastrointestinal-like) · Carcinosarcoma and other rare types
- Myometrium (uterine sarcoma)Carcinosarcoma and other rare types · Germ-cell and sex-cord stromal tumours (young women; highly curable)
- Placental site (gestational trophoblastic)
- Cervix, transformation zone
- Vulva
- obturator and external iliac
- internal iliac
- para-aortic (ovary, high uterus)
- inguinal (vulva)
Same organ: Endometrial cancer, Cervical cancer, Vulvar cancer, Gestational trophoblastic neoplasia
Testis and retroperitoneum
Germ cell tumours drain along the spermatic cord to the para-aortic nodes high in the abdomen, not to the groin, which is why staging scans look at the retroperitoneum.
- Germinal epitheliumSeminoma · Non-seminoma: embryonal carcinoma, yolk sac, choriocarcinoma, teratoma, mixed
- Epididymis and cord
- para-aortic (retroperitoneal)
- left renal hilum (left testis)
- inguinal (only after scrotal surgery)
Skin (cross-section)
Each skin cancer comes from a different cell layer: melanocytes and basal cells at the base of the epidermis, keratinocytes above them, Merkel cells and blood vessels in the dermis; depth of invasion decides the risk.
- Epidermis (in situ)Superficial spreading (most common cutaneous) · Lentigo maligna (chronically sun-damaged skin)
- Basal layer (melanocytes, basal cells)Nodular · Acral lentiginous (palms, soles, nails; KIT/NRAS; not UV-driven) · BRAF V600-mutant (~50%) · NRAS-mutant (~25%) · Triple wild-type
- Keratinocytes (squamous)
- Dermis (invasive; Breslow depth)
- Merkel cells (dermal-epidermal)Acral lentiginous (palms, soles, nails; KIT/NRAS; not UV-driven) · Uveal (GNAQ/GNA11, BAP1; HLA-A*02 tebentafusp)
- Dermal vessels (Kaposi)
- Acral and mucosal sitesAcral lentiginous (palms, soles, nails; KIT/NRAS; not UV-driven) · Mucosal (KIT, low TMB, poor IO response) · Desmoplastic (very high TMB, IO-sensitive)
- sentinel node in the draining basin
- regional basin (axilla, groin, neck)
Same organ: Basal cell carcinoma, Cutaneous squamous cell carcinoma, Merkel cell carcinoma, Kaposi sarcoma
Uveal melanoma arises in the pigmented choroid and ciliary body, retinoblastoma in the retina of infants; the eye has no lymphatics, so spread is through the blood (uveal melanoma almost always to the liver).
- Choroid and ciliary body (uveal melanoma)Choroidal melanoma (~90%) · Ciliary body melanoma · Iris melanoma (best prognosis) · GEP class 1A/1B (low risk) vs class 2 (high risk) · BAP1-mutant / monosomy 3 (high metastatic risk)
- Retina (retinoblastoma)
- Iris
- Optic nerve (route to the brain)
No lymphatic drainage: spread is haematogenous (uveal melanoma to the liver) or along the optic nerve (retinoblastoma).
Same organ: Retinoblastoma
Gliomas infiltrate along white matter and can cross the corpus callosum, medulloblastoma sits in the cerebellum, and CNS lymphoma favours deep periventricular tissue; none spread through lymph nodes.
- Frontal lobe (glioblastoma commonest)Glioblastoma, IDH-wild-type (WHO grade 4; TERT promoter, EGFR amplification, +7/−10) · Astrocytoma, IDH-mutant (grades 2-4; CDKN2A/B deletion defines grade 4)
- Temporal lobe
- Corpus callosum (butterfly glioma)
- Lower-grade IDH-mutant gliomaAstrocytoma, IDH-mutant (grades 2-4; CDKN2A/B deletion defines grade 4) · Oligodendroglioma, IDH-mutant and 1p/19q-codeleted (grades 2-3)
- Cerebellum (medulloblastoma)
- Brainstem (diffuse midline glioma)Diffuse midline glioma, H3 K27M-altered (including DIPG)
- Deep periventricular tissue (CNS lymphoma)
No conventional lymphatics: gliomas spread along white matter tracts and, rarely, through cerebrospinal fluid; medulloblastoma can seed the spine.
Same organ: Primary CNS lymphoma, Medulloblastoma
Head and neck, salivary glands and thyroid
Site decides cause and behaviour: HPV drives oropharyngeal cancer, EBV drives nasopharyngeal cancer, tobacco drives oral and laryngeal cancer; all drain into the neck node levels that surgeons and radiotherapists map.
- Oral cavity and tongueOral cavity · Oropharynx, HPV-negative
- Oropharynx: tonsil, base of tongue (HPV)Oropharynx, HPV-positive (p16+) · Oropharynx, HPV-negative
- Nasopharynx (EBV)Nasopharyngeal carcinoma (EBV-driven; endemic in southern China and Southeast Asia)
- Larynx and hypopharynxLarynx · Hypopharynx
- Parotid and other salivary glandsSalivary gland cancers (distinct histologies; HER2, AR, NTRK targets)
- Thyroid
- level I (submandibular)
- level II (upper jugular)
- level III-IV (jugular)
- level V (posterior)
- level VI (central, thyroid)
- retropharyngeal (nasopharynx)
Same organ: Nasopharyngeal carcinoma, Salivary gland cancers, Thyroid cancer
Bone marrow, lymph nodes and spleen
Leukaemias, myeloma and MDS live in the marrow and blood; lymphomas grow in lymph nodes and spleen. The node stations are the disease map, not a route of spread, and staging counts them.
- Bone marrow (leukaemia, MDS, MPN, myeloma)AML with defining genetic abnormalities (WHO 2022): NPM1-mutated, CEBPA bZIP, RUNX1::RUNX1T1, CBFB::MYH11, KMT2A-rearranged, DEK::NUP214, BCR::ABL1, MECOM · Acute promyelocytic leukaemia (PML::RARA), curable without chemotherapy in most cases (ATRA + arsenic) · AML, myelodysplasia-related (mutations in ASXL1, BCOR, EZH2, RUNX1, SF3B1, SRSF2, STAG2, U2AF1, ZRSR2 or MDS-type cytogenetics) · TP53-mutated AML / complex karyotype (adverse; ~10-15%) · Therapy-related AML after alkylators or topoisomerase II inhibitors · FLT3-ITD or FLT3-TKD (30%; targetable) · Blastic plasmacytoid dendritic cell neoplasm (CD123-high; related entity)
- Lymph node germinal centre (lymphomas)TP53-mutated AML / complex karyotype (adverse; ~10-15%)
- Spleen
- Blood (leukaemic phase)
- Lytic bone lesions (myeloma)
- Skin and extranodal sites
- cervical
- axillary
- mediastinal
- para-aortic and mesenteric
- inguinal
In lymphoma the node stations are the disease itself; staging (Ann Arbor / Lugano) counts how many regions and sides of the diaphragm are involved.
Same organ: Acute lymphoblastic leukaemia, Chronic lymphocytic leukaemia, Chronic myeloid leukaemia (CML), Diffuse large B-cell lymphoma, Follicular lymphoma, Hodgkin lymphoma, Mantle cell lymphoma, Multiple myeloma, Myelodysplastic syndromes / neoplasms (MDS), Myeloproliferative neoplasms (PV, ET, myelofibrosis), Waldenström macroglobulinaemia, Hairy cell leukaemia, Peripheral T-cell lymphomas (including cutaneous T-cell lymphoma), Blastic plasmacytoid dendritic cell neoplasm (BPDCN)
Bone and soft tissue (limb cross-section)
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.
- Metaphysis, near the growth plate (osteosarcoma)Bone sarcoma: osteosarcoma, Ewing sarcoma, chondrosarcoma, chordoma
- Shaft (Ewing sarcoma)Bone sarcoma: osteosarcoma, Ewing sarcoma, chondrosarcoma, chordoma
- Deep soft tissue compartmentSoft-tissue sarcoma: liposarcoma (well-differentiated/dedifferentiated, myxoid, pleomorphic), leiomyosarcoma, undifferentiated pleomorphic sarcoma, synovial sarcoma, myxofibrosarcoma, angiosarcoma, MPNST, rhabdomyosarcoma (paediatric) · Bone sarcoma: osteosarcoma, Ewing sarcoma, chondrosarcoma, chordoma · Desmoid tumour (CTNNB1/APC; locally aggressive, non-metastasising) · Tenosynovial giant cell tumour (CSF1-driven; benign)
- Skeletal muscle (rhabdomyosarcoma)Soft-tissue sarcoma: liposarcoma (well-differentiated/dedifferentiated, myxoid, pleomorphic), leiomyosarcoma, undifferentiated pleomorphic sarcoma, synovial sarcoma, myxofibrosarcoma, angiosarcoma, MPNST, rhabdomyosarcoma (paediatric) · Alveolar soft-part sarcoma (ASPSCR1-TFE3; IO-responsive)
- Neurovascular bundle (limb salvage decision)
Lymph node spread is rare (except epithelioid, synovial, clear cell and rhabdomyosarcoma); sarcomas go through the blood to the lungs.
Same organ: Osteosarcoma, Ewing sarcoma, Rhabdomyosarcoma
Not drawn (no single organ): Cancer of unknown primary (CUP).