What is neoplastic disease?
The word neoplasm, meaning new growth in Greek, refers to any abnormal growth, whether malignant or benign. Neoplastic disease refers to both malignant and benign growths.
All types of cancer fall into the category of malignant neoplastic diseases. Benign neoplastic diseases, or benign growths, can also negatively impact human health and leave skeletal evidence similar to that of malignant growths. It is important to analyze skeletal evidence for signs of both benign and malignant disease to better understand the dynamics of neoplastic disease in the past.
A benign growth is generally a slow growing, tumor localized to one area of the body. Some benign tumors may become malignant, such as giant-cell tumors, ovarian teratomas, meningiomas, and osteochondromas.
If the tumor is consistently growing, made up of poorly differentiated tissue, and has the potential to involve other parts of the body, it is considered malignant. Malignant growths, commonly known as cancer, are often defined by the rapid growth of abnormal cells that:
1) are capable of destroying surrounding normal tissue
2) do not adhere to normal growth-regulating mechanisms
3) can establish new growths in other regions of the body through vascular channels.
Two types of malignant tumors that involve the bone are sarcomas and carcinomas. Carcinomas occur in epithelial tissues, whereas sarcomas manifest in tissues that originate in the mesodermal layer, such as bone or muscle tissue. Sarcomas may metastasize, but metastasis is occurs more commonly in carcinomas.
PRIMARY CANCER, SECONDARY CANCER AND METASTASIS
Primary cancer refers to the first malignant tumor to form and its original location. If the primary cancer spreads, or metastasizes, the resulting cancer is called the secondary cancer. Most primary malignant tumours begin in the soft tissue and are therefore extremely difficult, and sometimes impossible, to detect in the skeleton through visual examination. Advances in biological analysis, however, may reveal new techniques for the identification of genetic or cellular mutations, cancer biomarkers, and immuno-assays.