Covering and lining cells
Begins in epithelial cells, which cover body surfaces and line many organs. Many common cancers are carcinomas.
ARCHIVE FILE 01CLASSIFICATION / ORIGIN / CELL TYPE
A family of diseases
Types of cancer.
More than 100 diseases.
A cancer’s name usually starts with where it formed. The kind of cell involved, its microscopic appearance, and its molecular features add more detail.
Melanoma begins in pigment-making melanocytes; fluorescent labels reveal selected structures.
NCI · Public domain ↗
“Cancer” is an umbrella term. Classification narrows the story from a broad disease family to a particular origin, cell type, subtype, and set of features.
01 / THE STARTING POINT
Where a cancer begins gives it its name.
Cancers are usually named for the organ or tissue where they first form. If cancer cells later spread elsewhere, the disease keeps the name of the original site. This is different from a new cancer that begins in the second location.
KEEP THE ORIGIN IN VIEW
A cancer found in another part of the body may still be classified by where it began. That origin helps shape testing and treatment.
02 / CELL & TISSUE FAMILIES
Broad categories describe what kind of cells are involved.
Bone and soft tissue
Begins in bone or soft tissues such as muscle, fat, blood vessels, or connective tissue.
Blood-forming tissue
Begins in blood-forming tissue such as bone marrow and generally does not form a solid tumor.
Lymphocytes
Begins in immune-system cells called lymphocytes. Hodgkin and non-Hodgkin lymphoma are broad groups with many subtypes.
Plasma cells
Begins in plasma cells, immune cells that normally make antibodies.
Melanocytes
Begins in pigment-making cells called melanocytes. Most melanomas form in skin, but they can begin in other pigmented tissues.
03 / CANCER MICROSCOPY GUIDES
Explore cancer types through their cellular evidence.
Each visual guide connects licensed microscopy with plain-language explanations of cell origin, tissue pattern, pathology, and biomarkers. The images are educational examples, never tools for self-diagnosis.
HEALTHY VS. CANCER
Breast cancer cells under the microscope
Compare organized breast tissue with cancer histology, then learn how ER, PR, and HER2 add molecular context.
Open breast cancer guide →RESEARCH MODELLung cancer cells under the microscope
Explore cultured A549 cells and learn why cell lines differ from diagnostic tissue.
Open lung cancer guide →TISSUE ARCHITECTUREColorectal cancer histology
Compare normal colorectal mucosa with adenocarcinoma and follow the route from screening to pathology.
Open colorectal cancer guide →TISSUE VS. CYTOLOGYPancreatic cancer under the microscope
Distinguish exocrine cancers, neuroendocrine tumors, and specimen methods.
Open pancreatic cancer guide →ELECTRON + FLUORESCENCEMelanoma cells under the microscope
See how imaging technique changes what a melanoma cell reveals.
Open melanoma guide →03 / ORGAN & BODY SYSTEM
The body site adds another layer.
NCI organizes specific information by body location and system, including breast, lung, colorectal, pancreatic, prostate, ovarian, kidney, thyroid, brain and spinal cord, blood, bone, skin, and many others. Each site contains distinct types and subtypes; an organ name alone is not the complete diagnosis.
- Solid tumors form a mass of tissue, although not every mass is cancer.
- Blood cancers begin in blood-forming or immune-system cells and may not form a solid mass.
- Central nervous system tumors are classified in specialized ways using cell type, location, and molecular findings.
04 / WHY DETAILS MATTER
Two cancers in the same organ may not be the same disease.
Microscopic pattern, grade, stage, and biomarkers can divide an organ-based cancer into more specific groups. Those differences can influence prognosis, which tests are useful, and which treatments are considered.
See how tissue is classified
Pathology connects the organ of origin to a cell and tissue pattern.
Pathology & diagnosis →Look inside the tumor
Biomarkers can reveal genes, proteins, and other features that are not visible by eye.
Genes & biomarkers →SOURCES / LEARN MORE
Continue with reviewed information.
NCIWhat Is Cancer?↗NCICancer Types↗General education only. Classification and diagnosis must come from a qualified clinical team.