Tumor – Types, Classification, Treatment

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)

1. BENIGN? TUMORS
   1. Osteoma
   2. Ossifying fibroma
   3. Myxoma of the jaw
   4. Osteochondroma
   5. Feline osteochondromatosis
   6. Chondroma
   7. Hemangioma
2. MALIGNANT TUMORS
   1. Central
      1. Osteosarcoma
         1. poorly differentiated
         2. osteoblastic
            • – nonproductive
            • – productive
         3. chondroblastic
         4. fibroblastic
         5. telangiectatic
         6. giant cell type
      2. Chondrosarcoma
      3. Fibrosarcoma
      4. Hemangiosarcoma
      5. Giant cell tumor of bone
      6. Multilobular tumor of bone
   2. Peripheral
      1. Periosteal chondrosarcoma
      2. Periosteal fibrosarcoma
      3. Maxillary fibrosarcoma (dogs)
      4. Periosteal osteosarcoma
      5. Parosteal osteosarcoma
   3. Joint tumors
      1. Synovial sarcoma
   4. Miscellaneous tumors
      1. Liposarcoma
      2. Malignant mesenchymoma
      3. Others
   5. Tumors of bone marrow
      1. Myeloma
      2. Malignant lymphoma?
3. TUMOR-LIKE LESIONS
   1. Fibrous dysplasia
   2. Solitary bone cyst
   3. Juxtacortical bone cyst
   4. Epidermoid cyst of the phalanx
   5. Myositis ossificans
   6. 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