What is a chondroid tumour?

A chondroid tumour is a type of growth or mass that contains tissue resembling cartilage. Cartilage is the firm, flexible tissue found in joints, the respiratory tract, and other body parts. Chondroid tumours can be benign (noncancerous) or malignant (cancerous).

When is this term used in a pathology report?

The term “chondroid tumour” is often used in a pathology report when the tumour has areas that resemble cartilage under the microscope. This description is commonly applied when examining a biopsy sample, especially when the small amount of tissue obtained makes it challenging to provide a more specific diagnosis. Chondroid tissue gives the pathologist clues, but further tissue sampling or additional tests may be needed for a more definitive diagnosis.

What does a chondroid tumour look like under the microscope?

Under the microscope, a chondroid tumour typically contains cells embedded in a smooth, glassy matrix, similar to the appearance of cartilage. The cells are called chondrocytes and are often found in spaces called lacunae within the matrix. Depending on the type of tumour, pathologists may also see areas of calcification (calcium deposits) or other features.

Are all chondroid tumours cancerous?

No, not all chondroid tumours are cancerous. Chondroid tumours can be benign (noncancerous) or malignant (cancerous). Benign tumours do not spread to other parts of the body, while malignant tumours have the potential to invade nearby tissues and metastasize (spread) to distant organs.

What features do pathologists use to determine if a chondroid tumour is benign or malignant?

Pathologists use several features to determine if a chondroid tumour is benign or malignant, including:

• Cell appearance: In benign tumours, the cells usually look more uniform and organized. In malignant tumours, the cells may appear more abnormal, with irregular shapes and sizes.
• Mitotic activity: This refers to the number of cells dividing. Malignant tumours tend to have more mitotic figures (active cell division), which suggests faster growth.
• Invasion: Benign tumours typically do not invade surrounding tissues, while malignant tumours may show signs of invasion into nearby structures.
• Necrosis: Malignant tumours may have areas of necrosis (dead cells), which can indicate more aggressive behaviour.

What are some examples of noncancerous chondroid tumours?

Some examples of noncancerous (benign) chondroid tumours include:

• Chondroma: A benign tumour made up of cartilage, typically found in the bones.
• Chondroid lipoma: A rare benign tumour that contains both fat and cartilage-like tissue.
• Pleomorphic adenoma: A benign tumour commonly found in the salivary glands that may have areas of chondroid tissue.

What are some examples of cancerous chondroid tumours?

Some examples of cancerous (malignant) chondroid tumours include:

• Chondrosarcoma: A malignant tumour that produces cartilage-like tissue. It is more aggressive and can spread to other parts of the body.
• Sarcomas with cartilaginous differentiation: These are cancers like liposarcoma and osteosarcoma that can have areas of chondroid tissue within them.
• Chordoma: A rare malignant tumour that arises from the bones of the skull and spine and can sometimes contain areas of chondroid tissue.