ACTIVE SURVEILLANCE
A type of disease management in which the healthcare team will keep a close eye on the disease instead of starting treatment right away. This approach can help to avoid or delay treatment.1
ASYMPTOMATIC
Having no signs or symptoms of disease.2
BIOPSY
A medical procedure that involves taking a sample of tissue from the body so it can be examined in a lab. 3
This procedure can be used to help diagnose a disease, by identifying abnormal cells in the tissue sample. It can also be used to assess the severity of a disease which has already been diagnosed.3
CSF1 (colony-stimulating factor 1)
CSF1 is a type of protein in the body. In healthy cells, CSF1 binds to its target (CSF1 receptor) and promotes tissue healing. However, in TGCT, CSF1 binding to (holding on to) its receptor causes tumor growth by recruiting inflammatory cells to the joint and causing them to multiply.4
CONTRAST (MRI)
A type of dye used in some MRI scans to make certain tissues and blood vessels show up more clearly and in greater detail.5,6
D-TGCT (diffuse TGCT)
A specific type of TGCT. Compared to nodular TGCT (see definition further down), diffuse tumors can extend beyond the joint. The most common location is usually the knee, but diffuse tumors can also occur in larger joints, like the hips. D-TGCT is less common than nodular-type TGCT (N-TGCT).7
HEMOSIDERIN
An iron-rich substance in the body. It can build up in areas of the body when red blood cells break down, sometimes due to bleeding.7–9
MALIGNANT
A term used to describe cancer. Malignant cells grow in an uncontrolled way, and can spread to other parts of the body through blood and other internal systems.10
MRI (magnetic resonance imaging)
A type of imaging scan used in radiology. This technique uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. MRI does not emit radiation.6
The results of an MRI scan can be used to help diagnose diseases, as well as plan treatment and assess how effective treatment has been.6
N-TGCT (nodular TGCT)
A specific type of TGCT. Compared to diffuse TGCT, (see definition above), tumors tend to be well-defined and stay within the joint. The most common location is usually the knee, but nodular tumors can also occur in smaller joints, like fingers and wrists. N-TGCT is more common than D-TGCT.7
NON-MALIGNANT
A term used to define a tumor as non-cancerous. It is a type of tumor that usually grows slowly and doesn’t typically spread to other parts of the body, like cancer can.11
PVNS (pigmented villonodular synovitis)
PVNS is another name for TGCT. PVNS is an older term, and now it is generally referred to as tenosynovial giant cell tumor (TGCT).5
RECURRENCE
Recurrence refers to when a tumor comes back, typically following treatment.12
SARCOMA
A type of cancer that begins in bone or in the soft tissues of the body, including cartilage, fat, muscle and blood vessels.13
TGCT (TENOSYNOVIAL GIANT CELL TUMOR)
A type of rare, non-malignant tumor occurring in the joints, often leading to pain, stiffness, swelling and limited range of motion in the affected joint. There are two types of TGCT – nodular and diffuse. TGCT is more common in women than men. The typical age for diagnosis is 35–50 years old.5