Tumor Terminology

Tumor

An abnormal mass of tissue in which cells divide more than they should, or do not die when they should.

Neoplasm

New and uncontrolled proliferation of cells, which can be benign or malignant.

Benign

A slow-growing tumor that is well circumscribed and does not infiltrate beyond the basement membrane.

Dysplasia

Change or alteration in a cell with atypical nuclei that can be classified as low or high grade.

Malignant

Cells that infiltrate the basement membrane and invade adjacent tissue, with poorly circumscribed margins.

Metastasis

The dissemination of malignant cells to distant organs where new tumors form.

Carcinoma

A malignant tumor that originates from epithelial cells.

Squamous cell carcinoma

A type of carcinoma that originates from squamous epithelial cells.

Adenocarcinomas

Malignant tumors that arise from glandular epithelial cells.

Small cell carcinoma

A type of carcinoma that originates from neuroendocrine cells.

Sarcomas

Rare malignant tumors that arise from mesenchymal tissue such as blood vessels, cartilage, bone, and muscle.

Osteosarcoma

A malignant tumor that originates in bone.

Liposarcoma

A malignant tumor that originates in adipose tissue.

Chondrosarcoma

A malignant tumor that originates in cartilage.

Leiomyosarcoma

A malignant tumor that originates in smooth muscle.

Rhabdomyosarcoma

A malignant tumor that originates in skeletal muscle.

Angiosarcoma

A malignant tumor that originates in blood vessels.

Hematopoietic neoplasms

Abnormal proliferation of cells in the bone marrow, blood, lymph nodes, spleen, or liver.

Lymphoma

A malignant tumor arising from lymphoid cells, specifically B or T lymphocytes.

Leukemia

Abnormal early hematopoietic cells in the bone marrow.

Melanoma

A malignant tumor that originates from melanocytes in the skin.

Brain tumor

A tumor that arises from neurons, glial cells, choroid plexus, or meninges.

Teratoma

A tumor that originates from germ cells, examples include dermoid cysts found in testes or ovaries, made up of ectoderm, endoderm, or mesoderm.