Nomenclature of neoplasms

Nomenclature of neoplasms

Nomenclature of neoplasms

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Benign vs. Malignant - Friend or Foe?

  • Benign Tumors (-oma): Generally localized, slow-growing, and non-invasive.
  • Malignant Tumors (-carcinoma, -sarcoma): Invasive, fast-growing, and have the potential to metastasize.

Benign vs. Malignant Tumor Cell Growth

FeatureBenignMalignant
DifferentiationWell-differentiated; resembles parent tissueVariable; can be anaplastic (undifferentiated)
Growth RateSlow; rare, normal mitosesRapid; numerous, atypical mitoses
Local InvasionCohesive, often encapsulated; non-invasiveInfiltrative growth; invades local tissue
MetastasisAbsentPresent; definitive sign of malignancy

⚠️ Malignant Mimics: Some "-omas" are malignant (e.g., Melanoma, Lymphoma, Seminoma).

Epithelial Neoplasms - Linings Gone Wild

  • Benign (-oma): Named based on cell of origin or microscopic architecture.
    • Adenoma: From glands or forms glandular patterns (e.g., colonic tubular adenoma).
    • Papilloma: Produces macroscopic or microscopic finger-like projections (e.g., laryngeal papilloma).
    • Cystadenoma: Large, hollow cystic masses (e.g., ovarian serous cystadenoma).
  • Malignant (-carcinoma): Arise from epithelium of any germ layer (ectoderm, endoderm, mesoderm).
    • Adenocarcinoma: Glandular growth pattern (e.g., lung, colon, prostate).
    • Squamous Cell Carcinoma: Forms nests of squamous cells, often with keratin pearls (e.g., skin, esophagus, lung).
  • Metastatic Spread: Carcinomas characteristically spread via lymphatics first.

Carcinoma in situ (CIS): A critical non-invasive stage. Features full-thickness dysplasia of the epithelium without penetration of the basement membrane. High potential to progress to invasive carcinoma if untreated.

Mesenchymal Neoplasms - Connective Chaos

  • Rule: Suffix indicates behavior. Benign tumors end in -oma; malignant tumors end in -sarcoma.
  • Fibrous Tissue
    • Benign: Fibroma
    • Malignant: Fibrosarcoma
  • Adipose Tissue (Fat)
    • Benign: Lipoma
    • Malignant: Liposarcoma
  • Cartilage
    • Benign: Chondroma
    • Malignant: Chondrosarcoma
  • Bone
    • Benign: Osteoma
    • Malignant: Osteosarcoma
  • Blood Vessels
    • Benign: Hemangioma
    • Malignant: Angiosarcoma

Lipoma vs Liposarcoma Histology

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood and adolescence, often presenting in the head, neck, or genitourinary tract.

Exceptions & Oddballs - What's in a Name?

  • Not all "-oma" suffixes denote benign tumors. Key malignant exceptions include:

    • Melanoma
    • Lymphoma & Leukemia
    • Mesothelioma
    • Seminoma
    • Hepatoma (Hepatocellular Carcinoma)
  • Hamartoma: A benign, focal malformation of disorganized but mature tissue native to the site of origin.

  • Choristoma (Ectopia): A mass of normal tissue in an abnormal location (e.g., pancreatic tissue in the stomach wall).

Hamartoma vs. Choristoma Definitions

Seminoma: A malignant germ cell tumor of the testis, it is the male counterpart to dysgerminoma in females and is notably very radiosensitive.

High‑Yield Points - ⚡ Biggest Takeaways

  • Benign tumors generally end in -oma (e.g., Lipoma). Malignant epithelial tumors are carcinomas; malignant mesenchymal tumors are sarcomas.
  • Key malignant exceptions ending in -oma include Melanoma, Lymphoma, Seminoma, and Hepatoma.
  • Teratomas are tumors derived from more than one germ layer.
  • A hamartoma is a disorganized mass of mature tissues native to the site of origin.
  • A choristoma is a mass of normal tissue in an ectopic location.

Practice Questions: Nomenclature of neoplasms

Test your understanding with these related questions

A 65-year-old man with a 40-pack-year smoking history presents with hemoptysis and a persistent cough. Chest CT shows a 3.5 cm centrally located mass in the right main bronchus. Positron emission tomography confirms a malignant nodule. Bronchoscopy with transbronchial biopsy is performed and a specimen sample of the nodule is sent for frozen section analysis. The tissue sample is most likely to show which of the following tumor types?

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Flashcards: Nomenclature of neoplasms

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A mesenchymal tumor is a _____

TAP TO REVEAL ANSWER

A mesenchymal tumor is a _____

sarcoma

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