Tumors (Neoplasia)

Neoplasia (tumors) are abnormal tissue proliferations, which develop exceeding normal tissue, uncoordinated with it. This uncontrolled tissue growing may continue even after cessation of the etiologic factor (self-maintained). The structure of a tumor (neoplasia) : parenchyma (tumor cells derived from previously normal cells) and stroma (vessels and connective tissue), in variable proportions.



Classification and nomenclature of tumors

Type of cells :

Benign

Malignant

A. Tumours composed of one parenchymal cell type

A.1. Epithelial tumours

Stratified squamous epithelium

Basal cells of skin or adnexa

Seborrheic keratosis

Glands or ducts

-

Papillary carcinoma

Cystadenoma

Cystadenocarcinoma

Respiratory tract epithelium

-

Bronchogenic carcinoma

Neuroectoderm

Malignant melanoma

Renal epithelium

Renal tubular adenoma

Liver cells

Liver cell adenoma

Bile ducts

Billiary adenoma

Bile duct carcinoma

Urinary tract epithelium (transitional)

Transitional cell papilloma

Transitional cell carcinoma

Placental epithelium - gestational trophoblast

Hydatidiform mole

Gestational choriocarcinoma

A.1. Mesenchymal tumours

Conjunctive tissue and derivatives

fibroblasts

Fibroma

lipoblasts

Lipoma

Liposarcoma

chondroblasts

Chondrosarcoma

osteoblaste

Endothelium and relative tissues

blood vessels

Angiosarcoma

lymphatic vessels

Lymphangioma

Lymphangiosarcoma

synovia

-

Synoviosarcoma

mesotelium

Solitary fibrous tumour of the pleura

Malignant mesothelioma

meninge

Meningioma

Invazive meningioma

Blood cells

Muscle fibers

smooth

Leiomyoma

Leiomyosarcoma

striated

Rhabdomyoma

Rhabdomyosarcoma

B. Tumours with different types of cells from the same germ layer - mixed tumours

Salivary glands

Pleomorphic adenoma (Mixed tumour of salivary gland origin)

Malignant mixt tumour of salivary gland origin

Breast

Malignant cystosarcoma phyllodes

Nephroblastem (metanephric blastema)

C. Tumours with different types of cells derived from more than one germ layer - teratogenous

Totipotential cells in gonads or in embryonic rests

Immature teratoma

Dermoid cyst

Teratocarcinoma (Embryonic carcinoma)

-

Endodermal sinus tumour

-

Non-gestational choriocarcinoma

Last updated : 01/30/2009