Why are some cancers described as small cell and some as large cell? What do these terms mean?

Answer From Edward T. Creagan, M.D.

The terms "small cell" and "large cell" describe what cancer cells look like under a microscope.

Looking at the cancer cells and noting their size and shape gives your health care team helpful clues about your diagnosis. It helps your care team figure out the type of cancer you have and where the cancer began. A careful study of the cancer cells can also show how much the cells have changed compared to healthy cells.

Your health care team uses this information along with test results for the size and spread of the cancer to determine:

  • The likely course or outcome of the cancer, which is also called the prognosis
  • The best treatment for a certain cancer
  • Whether surgery is an option

Terms used to describe what cancer cells look like under a microscope include:

  • Clear cell. The inside of the cell seems clear. Cancers with clear cells include some kidney, ovarian and uterine cancers.
  • Spindle cell. The cell is narrower at both ends than at the middle. Cancers with spindle cells include some breast, gastrointestinal, muscle or other soft tissue, and skin cancers.
  • Large cell. The cell is larger than a typical cell. Cancers with large cells include some types of lung cancer and lymphoma.
  • Small cell. The cell is smaller than a typical cell. Cancers with small cells include some types of lung cancer, prostate cancer and pancreatic neuroendocrine tumors. Sometimes these cancers are called small round cell cancers.
  • Squamous cell. The cell looks flat. In the body, these cells are often arranged like tiles on a floor. Squamous cell cancers include some types of skin cancer and some types of cancer that start in the lining of organs, such as the bladder.
  • Adenocarcinoma. The cell looks like a gland cell. Cancers with this type of cell include some types of breast, prostate, lung, gastric and endometrial cancers.
  • Anaplastic. The cell looks very irregular. These cells may have an unusual size and may not resemble any typical cells. It may be hard to tell where these cells come from.
  • Metaplastic. The cell has many different looks. Metaplastic cancers are made up of many different types of cells that look different from each other.
  • Poorly differentiated. The cell appears very irregular. In typical tissue, cells in a certain area look different from cells in another area. For example, breast cells look different from colon cells. If cells look very unlike typical cells, they are considered poorly differentiated. In general, these cancers may be aggressive.

Other factors that help classify a cancer include:

  • Part of the body in which the cancer started. Cancers are named for where they start. For example, if breast cancer spreads into the liver, it is still called breast cancer.
  • Type of tissue from which the cancer started. Some terms used to describe cells can tell you about where the cancer started. For example, carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer of the bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

With

Edward T. Creagan, M.D.

Follow on Twitter: @EdwardCreagan

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Aug. 26, 2022 See more Expert Answers

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  12. Myths about cancer causes
  13. Infographic: Cancer Clinical Trials Offer Many Benefits
  14. Cancer diagnosis: 11 tips for coping
  15. Cancer-related fatigue
  16. Cancer pain: Relief is possible
  17. Cancer-prevention strategies
  18. Cancer risk: What the numbers mean
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  21. Cancer survivors: Care for your body after treatment
  22. Cancer survivors: Late effects of cancer treatment
  23. Cancer survivors: Managing your emotions after cancer treatment
  24. Cancer survivorship program
  25. Cancer treatment
  26. Cancer treatment myths
  27. Cancer-related fatigue
  28. Cancer-related pain
  29. Cancer-related weakness
  30. Chemo targets
  31. Chemoembolization
  32. Chemotherapy
  33. Chemotherapy and hair loss: What to expect during treatment
  34. Chemotherapy and sex: Is sexual activity OK during treatment?
  35. Chemotherapy nausea and vomiting: Prevention is best defense
  36. Chemotherapy side effects: A cause of heart disease?
  37. Complete blood count (CBC)
  38. Cough
  39. CT scan
  40. Curcumin: Can it slow cancer growth?
  41. Cancer-related diarrhea
  42. Eating during cancer treatment: Tips to make food tastier
  43. Fatigue
  44. Fertility preservation
  45. Heart cancer: Is there such a thing?
  46. High-dose vitamin C: Can it kill cancer cells?
  47. Honey: An effective cough remedy?
  48. Infographic: CAR-T Cell Therapy
  49. Intensity-modulated radiation therapy (IMRT)
  50. Intrathecal chemotherapy
  51. Joint pain
  52. Low blood counts
  53. Magic mouthwash
  54. Medical marijuana
  55. Microwave ablation for cancer
  56. Mindfulness exercises
  57. Minimally invasive cancer surgery
  58. Monoclonal antibody drugs
  59. Mort Crim and Cancer
  60. Mouth sores caused by cancer treatment: How to cope
  61. MRI
  62. Muscle pain
  63. Needle biopsy
  64. Night sweats
  65. No appetite? How to get nutrition during cancer treatment
  66. Palliative care
  67. PALS (Pets Are Loving Support)
  68. Pelvic exenteration
  69. PET/MRI scan
  70. Precision medicine for cancer
  71. Radiation therapy
  72. Seeing inside the heart with MRI
  73. Self-Image During Cancer
  74. Sentinel lymph node mapping
  75. Sisters' Bone Marrow Transplant
  76. Sleep tips
  77. Stem Cells 101
  78. Stem cells: What they are and what they do
  79. Surgical biopsy
  80. Tumor vs. cyst: What's the difference?
  81. TVEC (Talimogene laherparepvec) injection
  82. Ultrasound
  83. Unexplained weight loss
  84. Stem cell transplant
  85. How cancer spreads
  86. MRI
  87. PICC line placement
  88. When cancer returns: How to cope with cancer recurrence
  89. Wide local skin excision
  90. X-ray