Neoplasia - 2

1. Neoplastic Nomeclature

   1. Neoplasms are named according to a binomial system denoting their::

      1. Histogenetic origin of the parenchymal cells: refering to the tissue or cell type from which the tumor arose and can generally be divided into epithelial and mesenchymal types

      2. Biological behavior: which includes the degree of tumor cell differentiation and pattern of growth and is divided into benign and malignant.

         1. Benign Tumors: ‘~oma’

            1. e.g., papilloma; osteoma

         2. Malignant Tumors: ‘~carcinoma, ~sarcoma’

            1. e.g., squamous cell carcinoma; osteosarcoma

         3. Mixed Tumors – originated from more than one germ layer, or created by a divergent differentiation of a single line of parenchymal cells into another tissue, thus ‘pleomorphic ~oma’ is the preferred designation; benign or malignant

         4. Polyp- The term polyp is applied to any macroscopically visible nodule or mass that projects above the level of the surrounding mucosa or epidermis. It can be classified as non-neoplastic or neoplastic.

            1. Non-neoplastic polyp appears to be of a hyperplastic nature and is believed to be associated with a chronic inflammation or irritation. Acrochordon (skin tag), for example, is fibroepithelial polyp common in old people and dogs.

            2. In neoplasms, the term polyp is preferably restricted to benign tumors. Malignant polyps are better designated polypoid cancer.

            3. Teratomas – made up of a variety of parenchymal cell types of more than 1 germ layer, usually all 3.

         5. Inappropriate but deeply entrenched exceptions – melanoma, seminoma, hepatoma, choristoma, etc.

Category: Pathology Notes