Neoplasia Nomenclature

NEOPLASIA Neoplasia means th e process of "new growth" .T he term tumo ur is used as a synonym for neoplasia, but in fact tumour means swelling which could be ca used by inflammation or other causes, but Neoplasia is a more scientific word than Tumour . Onc ology (Greek onc...

NEOPLASIA Neoplasia means th e process of "new growth" .T he term tumo ur is used as a synonym for neoplasia, but in fact tumour means swelling which could be ca used by inflammation or other causes, but Neoplasia is a more scientific word than Tumour . Onc ology (Greek oncos = tumo ur) is the study of neoplasms. The doctor who treat patients with neoplasms are called oncologist. Cancer is the common name for all malignant tumo urs. T he ancient or igin of (cancer) is probably derives from the La tin for crab. M alignant tumours are like cancer because they can firmly attach itself to anything that they can catch and because cancers has multiple limbs . A neoplasm is define d as an abnormal mass of tissue, the growth of which is uncontroll ed and persis ts after cessa tion of the stimuli which caused the grow th. Tumo urs are the result of some gen etic alterations . These genetic changes allow excessive and uncontrolled proliferation of cells that are independent of physiologic growth stimuli . Neoplastic cells are said to be clonal because t he whole population of cells within a tumo ur originate from an abnormal single cell that has developed genetic change . BENIGN & MALIGNANT TUMOURS Tumours are divided according to their biological behaviour into benign and malignant . Be nign tumours are well -defined with regular margins, slowly growing; do not recur afte r complete surgical excision and they have no potential for distant metastasis ( spread to other parts of the body beyond its a natomic site). Malignant tumour s have irregul ar margins, rapidly growing, locally invasive and can metastasise; therefore they may recur following surgical excision. A significant number of tumours are classified as borderline tumours or tumours of uncertain malignant potential. In the se tumours, t he pathologist can not be sure after microscopic examination if the tumour behaves in a b enign or in a malignant way . Nomenclature of Neoplasm s Tumours are classified according to their cell of origin, differentiation and predictive behaviour . There are a hug e number of tumours, to avoid confusions, pathologists made rules to classify them , but the rules have some exceptions. ⦿ Naming Benign Tumo urs In general, benign tumo urs are designated by attaching the suffix -oma to the cell of origin. Tumo urs of mes enchymal cells (mesodermal origin ) generally follow this rule. For example, a benign tumo ur arising from fibroblastic cells is called a fibroma , a cartilaginous tumo ur is called chondroma , and a tumo ur of osteoblasts is an osteoma . We need to remember that there are exceptions to this rule, as some malignant tumours also end w ith the suffix -oma, for example, seminoma is a malignant testicular tumour, lymphoma is a malignant tumour of lymphoid tissue s and melanoma is the name for malignant tumours of melan ocytes (malignant melanoma). Nomenclature of benign epithelial tumours is more comple x. S ome are classified according to the cells of origin, others are named based on macroscopic or microscopic architecture . For example: Adenoma is the term applied to a benign epithelial neoplasm derived from glands or forms glandular pattern , e.g. thyroid adenoma, salivary gland adenomas, colonic or gastric adenomas. Papilloma is a b enign epithelial neoplas ms producing finger -like projections fro m epithelial surfaces. Tumours that form large cystic masse s, as in the ovary, are called cystadenoma . ⦿ Nomenclature of Malignant Tumours Malignant t umo urs of mesenchymal cells are called sarcoma . For example, a malignant tumo ur arising from fibroblastic cells is called a fib ro sarcoma , a malignant cartilaginous tumo ur is a chondro sarcoma , and a malignant tumo ur of osteoblasts is an osteo sarcoma . Malignant tumours of epithelial origin are called carcinoma . For example most epithelial tumours of the skin and the oral cavity ar e squamous cell carcinoma , if they arise from the basal cells of the epidermis of the skin then it is called basal cell carcinoma . M ost m alignant tumours of the colon , sto mach and the endometrium and are called adenocarcinoma . Sometimes, the name of the t umour describes the tumour cell mor phology or the main cell type of the tumour , for example cle ar cell carcinoma (the cells have white cytoplasm ), papillary carcinoma (the tumou r mak es papillary projections), folli cular carcinoma (the tumour make s follicle s). ⦿ Some tumour s originate from more than one germinal layer (endoderm and mesoderm) giving rise to a mixture of epithelial and mesenchymal tissue components , like benign mixed tumour (pleomorphic adenoma of the salivary gland and fibroadenoma of the female b reast ) or malignant mixed tumour (like carcinosarcoma of the ovary). Teratoma is a tumour that originates from all three germ lines (ectoderm, mesoderm and endod erm) . Teratomas can be benign or malignant de pending on its histological components and the age of the patient . Hamartoma, Choristoma , Haematoma, Antibioma Despite the suffix (oma) in these pathologies, t hese are not true neoplasms . Hamartoma is a non -neoplastic abnormal disorganized mass of tissue whose cell types are indigenous to the site of the lesion. Choristoma is an ectopic focus of normal tissue (heterotopia) that is pre sent in the wrong anatomic site , example ectopic thyroid or adrenal tissue. An Antibioma is a solidified abscess that has been treated with antibiotics and not evacuated. Hae matoma is collection of blood forming a mass in the tissue.