Malignant tumours of bone and cartilage

Chondrosarcoma, including mesenchymal chondrosarcoma

Definition

Chondrosarcoma is a malignant tumour of hyaline cartilage.

Mesenchymal chondrosarcoma is a malignant small round cell neoplasm with focal cartilaginous differentiation, and often with a pericytomatous vascular pattern.

ICD-O codes

Chondrosarcoma 9220/3

Mesenchymal chondrosarcoma

9240/3

Synonym

Polyhistioma

Epidemiology

These tumours are rare in the facial skeleton. Chondrosarcomas account for <16% of all sarcomas of the nasal cavity, paranasal sinuses and nasopharynx {256,463,1367,4045}. Chondrosarcoma affects older adults, with a male predilection.

Mesenchymal chondrosarcoma is extremely rare, and affects young adults, with a female predilection.

Localization

Chondrosarcoma involves the alveolar portion of the maxilla, the maxillary sinus or the nasal septum. Mesenchymal chon-

Fig. 1.60 Chondrosarcoma. CT shows a destructive lesion arising in nasal cavity invading into maxillary sinus. Note focal calcification.

drosarcoma involves the mandible and maxilla almost equally.

Clinical features

Patients with involvement of the nose present with nasal obstruction. Painful swelling is common with other sites of involvement.

Imaging

On plain radiographs, both tumours show osteolysis with stippled calcification, cortical destruction and possible soft tissue extension. Computerized tomograms and magnetic resonance images are useful in evaluating the extent of disease {463}.

Macroscopy

Chondrosarcomas are lobulated pale-blue glistening masses that may show cystic change. Mesenchymal chon-drosarcomas have the fish-flesh appearance of high-grade sarcomas; chalky foci of calcification may offer a diagnostic clue.

Histopathology

Chondrosarcomas are often lobulated, and show round to oval cells in lacunae with a blue chondroid matrix that may show myxoid changes. Most are low-grade. Increased cellularity and permeation of the intertrabecular spaces of bone, if identified, are the most important features that distinguish chondrosarco-ma from chondroma. Radiological corre-

Fig. 1.61 Chondrosarcoma. Glistening pale blue fragments of cartilage.

Fig. 1.62 Mesenchymal chondrosarcoma. A Small cells with scant cytoplasm arranged in a "haeman-giopericytoma-like" pattern around open vascular channels without chondroid matrix identified in this field. B Normal Haversian bone is invaded by chondrosarcoma which blends with areas of undifferentiated mesenchymal cells (lower right). C The chondroid matrix shows lacunar spaces filled with the same nuclei identified in the mesenchymal component. Vague lacunar spaces surround the undifferentiated mesenchymal cells which display coarse nuclear chromatin in irregularly shaped nuclei. From P.D. Knott et al. {1343}.

Fig. 1.62 Mesenchymal chondrosarcoma. A Small cells with scant cytoplasm arranged in a "haeman-giopericytoma-like" pattern around open vascular channels without chondroid matrix identified in this field. B Normal Haversian bone is invaded by chondrosarcoma which blends with areas of undifferentiated mesenchymal cells (lower right). C The chondroid matrix shows lacunar spaces filled with the same nuclei identified in the mesenchymal component. Vague lacunar spaces surround the undifferentiated mesenchymal cells which display coarse nuclear chromatin in irregularly shaped nuclei. From P.D. Knott et al. {1343}.

lation is required for a definitive diagnosis {4045}.

Mesenchymal chondrosarcomas show a mixture of hyaline cartilage and small round to oval cells with hyperchromatic nuclei, frequently arranged in a pericy-tomatous vascular pattern. These cells

Osteosarcoma Maxilla
Fig. 1.63 CT of an osteosarcoma of the maxilla. The destructive lesion extends into soft tissue, producing a sunburst pattern of tumour bone.

Fig. 1.64 CT of an unusual osteosarcoma arising in nose. The mineral present suggests cartilage differentiation.

Fig. 1.66 Osteosarcoma. Gross specimen of osteosarcoma. The tumour is fleshy and surrounds the root of a tooth.

are frequently immunoreactive for CD99. The relative amounts of the two elements are quite variable. The chondroid lobules have the appearance of well-differentiated chondrosarcoma.

Prognosis and predictive factors

Chondrosarcomas are associated with an excellent prognosis if the lesions are completely resected. Approximately 20% of patients die of tumour, most often with uncontrolled local recurrence {2223,4045}

Mesenchymal chondrosarcoma is a high-grade tumour with an unpredictable prognosis. Patients with tumour of the facial skeleton do better than those with tumours of the remainder of the skeleton {2687}.

Osteosarcoma

Definition

Osteosarcoma is a primary malignant tumour of bone in which the neoplastic cells produce osteoid or bone.

ICD-O code 9180/3

Synonym

Osteogenic sarcoma Epidemiology

Osteosarcomas of the jaws are very rare, with an incidence of 0.7 per million {868}. They are extremely rare in other head and neck sites. Patients are a decade older than those with extragnathic osteosarcomas {455,868,1366}. There is a modest male predilection.

Etiology

Over 10% of tumours are post-radiation, including Thorotrast exposure.

Localization

The maxilla and the mandible are affected almost equally. In the maxilla, the alveolar ridge and the antrum are predominantly involved, whereas in the mandible, the body is the main site.

Clinical features

Symptoms include swelling with or with

Fig. 1.65 Osteoblastic osteosarcoma with a typical filigree pattern of osteoid formation.

out pain and loosening of teeth. On plain radiograph, the tumour is usually lytic but may be sclerotic or mixed. In over half of the lesions, there is soft tissue extension. Computerized tomogram is better in demonstrating matrix mineralization and soft tissue extension {1457}.

Macroscopy

The tumours vary from the lobulated blue colour of cartilage to fleshy white to densely sclerotic masses.

Histopathology

Osteosarcomas of the jaws are generally better differentiated than extragnathic osteosarcomas. There is commonly chondroblastic differentiation, characterized by lobules of atypical-appearing chondrocytes in lacunae. There is a typical condensation of nuclei toward the periphery of the lobules, where sheets of spindle cells may be seen. The centre of the chondroid lobules shows bone formation in the form of trabeculae. The remainder show osteoblastic or fibroblastic features. It is unusual to see benign giant cells within the tumour.

Prognosis and predictive factors

Some studies have shown that patients with osteosarcoma of the jaws have a better survival than those with extragnathic osteosarcomas {455,1366}. However, some other studies {206,868} have not confirmed this finding. Complete surgical resection is associated with better prognosis.

Fig. 1.65 Osteoblastic osteosarcoma with a typical filigree pattern of osteoid formation.

Was this article helpful?

0 0
Delicious Diabetic Recipes

Delicious Diabetic Recipes

This brilliant guide will teach you how to cook all those delicious recipes for people who have diabetes.

Get My Free Ebook


Post a comment