Nomenclature of Neoplasms
Comparisons between Benign and Malignant Neoplasms
Pattern of Growth
Rate of Growth
- benign: usually expansive with encapsulation, fibrous capsule
- malignant: infiltrative and expansive without encapsulation, both lmph and blood vascular involvement
benign: usually uniform, resembles tissue of origin and is "well-differentiated"
malignant: anaplasia = poorly differentiated (but note that malignant tumors range from well-differentiated to undifferentiated)
- benign: usually slow growing, mitotic figures are rare and normal in appearance
- malignant: slow or rapid growth, mitoses often numerous and abnormal
Recurrence after Removal
benign: unusual if adequately excised
benign: not observed
malignant: often encountered
- Pleomorphism: increased N/C ratio, large nucleoli, atypical mitosis
Nomenclature of Neoplasms based on tissue of origin, and whether the tumor is benign or malignant.
Papilloma Benign epithelial neoplasm producing macroscopically or microscopically visible fingerlike or warty projects from epithelial surfaces.
Teratoma Neoplasms made up of cellular elements representing more than or (usually all three) of the embryonic germ layers.
- Benign (-oma)
- Benign epithelial neoplasm that forms a glandular pattern.
- A neoplasm derived from glands but does not necessarily form glandular patterns.
- example: thyroid follicular adenoma, cystadenoma of ovary, adrenocortical adenoma
Hamartoma A disorganized mass of mature, specialized tissues or cells indigenous to a particular site.
- example: Ovarian teratoma the ovary had ectodermal growth in it
Choristoma Nests of "normal" tissues in ectopic locations.
- example: Lung hamartoma mixture of mature respiratory and cartilage cells in the lung.
Benign or Malignant
Benign or malignant neoplasm that produces a macroscopically visible projection above a mucsal surface.
- example: a piece of lung growing in your leg. Another controversial example is "head up your ass".
malignant epithelial neoplasm (two types)
- example: colonic polyp (nomeoplastic/hyperplastic or neoplastic/adenoma), polypoid cancers.
Sarcoma Malignant mesenchymal neoplasm (mesenchymal means anything that is not epithelial)
- example: Adenocarcinoma, squamous cell carcinoma, or can specify site (renal cell adenocarcinoma), or can specify differentiation (large cell undifferentiated carcinoma of lung).
Benign and Malignant
- example: liposarcoma, osteosarcoma, chondrosarcoma
adenofibronoma/fibroadenoma, carcinosarcoma/malignant mixed tumor.
Inappropriate Nomenclature Youd think they are benign but they are malignant
- Tumors with "Mixed" Differentiation
- Hepatoma hepatocelluar carcinoma
- Melanoma melanocarcinoma