A tumor is a mass of tissue that’s formed by an accumulation of abnormal cells. Normally, the cells in your body age, die, and are replaced by new cells. With cancer and other tumors, something disrupts this cycle. Tumor cells grow, even though the body does not need them, and unlike normal old cells, they don’t die.
A classification of bone tissue and cartilaginous tissue tumors depending on histological structure recognizes, in spite of al inherent difficulties, the neoplasms specific for these tissues, as well as the possibility of cancerization of other structures, such as blood vessels, connective tissue or periarticular tissues [rx,rx].
Tumor – Types, Classification
The anatomohistological classification includes:
-
– osteoma;
-
– osteoid osteoma;
-
– osteosarcoma;
-
– juxtacortical osteosarcoma;
-
– fibrosarcoma;
-
– liposarcoma;
-
– osteoliposarcoma;
-
– chondroma;
-
– osteochondroma;
-
– chondrosarcoma;
-
– multilobular bone tumor;
-
– bone marrow tumors: myeloma;
-
– vascular tumors; hemangioma; hemangiosarcoma;
-
– mixed bone tumors;
-
– metastatic bone tumors;
-
– tumor-like bone lesions: solitary bone cyst; aneurysmal bone cysts;
-
– articular and adnexal structure tumors: synovial sarcoma; fibroxanthoma; malignant giant cell tumor of the connective tissue.
Histological Classification of Bone and Joint Tumors of Domestic Animals (Slayter et al. 1994)
-
BENIGN TUMORS
-
Osteoma
-
Ossifying fibroma
-
Myxoma of the jaw
-
Osteochondroma
-
Feline osteochondromatosis
-
Chondroma
-
Hemangioma
-
-
MALIGNANT TUMORS
-
Central
-
Osteosarcoma
-
poorly differentiated
-
osteoblastic
-
– nonproductive
-
– productive
-
-
chondroblastic
-
fibroblastic
-
telangiectatic
-
giant cell type
-
-
Chondrosarcoma
-
Fibrosarcoma
-
Hemangiosarcoma
-
Giant cell tumor of bone
-
Multilobular tumor of bone
-
-
Peripheral
-
Periosteal chondrosarcoma
-
Periosteal fibrosarcoma
-
Maxillary fibrosarcoma (dogs)
-
Periosteal osteosarcoma
-
Parosteal osteosarcoma
-
-
Joint tumors
-
Synovial sarcoma
-
-
Miscellaneous tumors
-
Liposarcoma
-
Malignant mesenchymoma
-
Others
-
-
Tumors of bone marrow
-
Myeloma
-
Malignant lymphoma
-
-
-
TUMOR-LIKE LESIONS
-
Fibrous dysplasia
-
Solitary bone cyst
-
Juxtacortical bone cyst
-
Epidermoid cyst of the phalanx
-
Myositis ossificans
-
Villonodular synovitis
-
Diagnosis in bone tumors is based on the correlation of data obtained following clinical, radiological and histopathological examination. It is important that clinical data should include the species, breed, age, position in the skeleton and number of affected bones, the duration and evolution of the tumor, as well as the general state of the subject.
The World Health Organization lists the following cell types in its classification of soft tissue sarcomas:[5,6]
- Adipocytic tumors.
- -Atypical lipomatous tumor.
- -Well-differentiated liposarcoma.
- -Liposarcoma, not otherwise specified.
- -Dedifferentiated liposarcoma.
- -Myxoid/round cell liposarcoma.
- -Pleomorphic liposarcoma.
- Fibroblastic/myofibroblastic tumors.
- -Dermatofibrosarcoma protuberans.
- -Fibrosarcomatous dermatofibrosarcoma protuberans.
- -Pigmented dermofibrosarcoma protuberans.
- -Solitary fibrous tumor, malignant.
- -Inflammatory myofibroblastic tumor.
- -Low-grade myofibroblastic sarcoma.
- -Adult fibrosarcoma.
- -Myxofibrosarcoma.
- -Low-grade fibromyxoid sarcoma.
- -Sclerosing epithelioid fibrosarcoma.
- So-called fibrohistiocytic tumors.
- -Giant cell tumor of soft tissues.
- Smooth muscle tumors.
- -Leiomyosarcoma (excluding skin).
-
Pericytic (perivascular) tumors.
-
Malignant glomus tumor.
-
- Skeletal muscle tumors.
- -Embryonal rhabdomyosarcoma (including botryoid, anaplastic).
- -Alveolar rhabdomyosarcoma (including solid, anaplastic).
- -Pleomorphic rhabdomyosarcoma.
- -Spindle cell/sclerosing rhabdomyosarcoma.
- Vascular tumors of soft tissue.
- -Retiform hemangioendothelioma.
- -Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma.
- -Epithelioid hemangioendothelioma.
- -Angiosarcoma of soft tissue.
- Chondro-osseous tumors.
- -Extraskeletal osteosarcoma.
-
Nerve sheath tumors.
-
Malignant peripheral nerve sheath tumor.
-
Epithelioid malignant peripheral nerve sheath tumor.
-
Malignant Triton tumor.
-
Malignant granular cell tumor.
-
Bone tumors
The differential diagnosis for bone tumors is dependent on the age of the patient, with a very different set of differentials for the pediatric patient.
- bone tumors
- bone-forming tumors
- adamantinoma of long bones
- enostosis (bone island)
- exostosis
- subungual exostosis
- osteoid osteoma
- osteoblastoma
- osteopoikilosis
- osteoma
- paranasal sinus osteoma
- skull vault osteoma
- osteosarcoma
- periosteal osteosarcoma
- parosteal osteosarcoma
- string sign
- cartilage-forming tumors
- chondroblastoma
- chondromyxoid fibroma
- chondrosarcoma
- conventional intramedullary chondrosarcoma
- juxtacortical chondrosarcoma
- clear cell chondrosarcoma
- myxoid chondrosarcoma
- mesenchymal chondrosarcoma
- extraskeletal chondrosarcoma
- dedifferentiated chondrosarcoma
- enchondroma
- enchondroma vs low grade chondrosarcoma
- enchondromatosis (Ollier disease)
- Maffucci syndrome
- juxtacortical chondroma
- osteochondroma
- hereditary multiple exostoses
- dysplasia epiphysealis hemimelica (Trevor disease)
- fibrous bone lesions
- desmoplastic fibroma
- fibrosarcoma of bone
- fibrous dysplasia
- Mazabraud syndrome
- McCune-Albright syndrome
- rind sign
- liposclerosing myxofibrous tumor (LSMFT)
- malignant fibrous histiocytoma (MFH)
- ossifying fibroma
- fibroxanthoma
- fibrous cortical defect
- non-ossifying fibroma
- bone marrow tumors
- Ewing sarcoma
- Langerhans cell histiocytosis
- multiple myeloma
- primary bone lymphoma
- secondary bone lymphoma
- solitary bone plasmacytoma
- solitary bone plasmacytoma with minimal bone marrow involvement
- other bone tumors or tumor-like lesions
- adamantinoma
- aneurysmal bone cyst
- benign fibrous histiocytoma
- chordoma
- giant cell tumor of bone
- paint brush borders sign
- Gorham massive osteolysis
- hemangioendothelioma
- musculoskeletal hemangioendothelioma
- haemophilic pseudotumor
- intradiploic epidermoid cyst
- intraosseous lipoma
- cockade sign
- musculoskeletal angiosarcoma
- musculoskeletal hemangiopericytoma
- primary intraosseous hemangioma
- post-traumatic cystic bone lesion
- simple bone cyst
- skeletal metastases
- morphology
- blow out bone metastases
- cookie bite skeletal metastases
- lytic bone metastases
- mixed lytic and sclerotic bone metastases
- sclerotic bone metastases
- location
- epiphyseal lesions (mnemonic)
- diaphyseal lesions (mnemonic)
- metaphyseal lesions
- distal appendicular skeletal metastases
- skull metastases
- patellar tumors
- vertebral metastases
- impending fracture risk
- Harrington criteria
- Mirel classification
- morphology
- staging
- AJCC staging of musculoskeletal tumors
- Enneking surgical staging system
- approach
- describing a bone lesion
- bone-forming tumors
About the author