|Year : 2015 | Volume
| Issue : 3 | Page : 194-197
Cytological diagnosis of chondrosarcoma: A case report with review of literature
Karuna Daswani, S Sudhamani, Ajita Pandit
Department of Pathology, Padmashree Dr. Dnyandeo Yashwantrao Patil Medical College, Nerul, Navi Mumbai, Maharashtra, India
|Date of Web Publication||16-Sep-2015|
Dr. S Sudhamani
Department of Pathology, Padmashree Dr. Dnyandeo Yashwantrao Patil Medical College, Nerul, Navi Mumbai - 400 706, Maharashtra
Source of Support: None, Conflict of Interest: None
Chondrosarcoma is a malignant tumor of bone showing cartilaginous differentiation. Fine needle aspiration cytology (FNAC) is found to be effective in the preoperative diagnosis of chondrosarcoma combined with radiological and clinical evaluation. Ribs is one of the most common skeleton sites for chondrosarcoma, the others being pelvis, proximal femur, proximal humerus and distal femur. We are presenting the case of a 40-year-old man who presented with a tumor in the anterior chest wall on the left side. On FNAC of the mass, a diagnosis of low-grade chondrosarcoma was made which was later confirmed on histopathology.
Keywords: Chest wall tumor, chondrosarcoma, FNAC, rib
|How to cite this article:|
Daswani K, Sudhamani S, Pandit A. Cytological diagnosis of chondrosarcoma: A case report with review of literature. J Sci Soc 2015;42:194-7
| Introduction|| |
Chondrosarcoma is a malignant tumor of bone with hyaline cartilage differentiation, which can arise either as primary or secondary to underlying tumor such as enchondroma or osteochondroma. Chondrosarcoma comprises 10-15% of all primary bone tumors and forms 20% of all malignant bone tumors.  It is the third most common primary malignant tumor of bone after myeloma and osteosarcoma. 
The incidence of chondrosarcoma peaks in the sixth and seventh decade of life. Chondrosarcoma is said to have a predilection for trunk bones, which are reportedly involved in nearly 50% of the cases, with rib and pelvis being the most common sites of involvement.
It is important to differentiate chondrosarcoma from benign chondroma and other malignant bone tumors like chondroblastic osteosarcoma and metastatic tumors. Fine needle aspiration cytology (FNAC) therefore plays an important role in the preoperative diagnosis combined with radiological studies.
| Case Report|| |
A 40-year-old male patient presented with lower left anterior chest wall mass since two years. The mass was initially small but gradually progressed in six months. There was no history of pain or trauma.
On clinical examination, swelling was seen at the anterior chest wall, 18 × 7 cms, transversely mobile, bony hard and non-tender. A diagnosis of primary tumor of bone was made clinically with the differential diagnosis of osteochondroma and osteosarcoma.
Chest X-ray showed soft tissue fullness in left anterior chest wall with central calcification. There was no evidence of pulmonary metastasis or pleural effusion.
Computed tomography scan showed an abnormal well-defined lesion measuring 11 × 4.5 × 7.5 cms in the left lower anterior chest and upper abdomen wall arising from anterior margin of lower ribs from D8 to D12 levels, suggestive of soft tissue neoplasm with no obvious osseous and pulmonary metastasis.
The FNAC of the swelling was done. It yielded thick and gelatinous material. Smears were prepared and stained with both Papanicolaou and Giemsa stains.
Microscopy revealed cellular smears with clusters and sheets of atypical chondrocytes displaying eccentric nuclei and abundant vacuolated cytoplasm. Background showed abundant chondromyxoid matrix. Osteoid was not seen [Figure 1].
|Figure 1: 10´, PAP of FNAC smear showing malignant chondrocytes in a chondromyxoid background|
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Based on these features, cytological diagnosis of chondrosarcoma was made. Excision biopsy was performed.
Grossly, the specimen consisted of a soft tissue mass measuring 13 × 8 × 5 cms. Rib bone was not attached. External surface was partially encapsulated, round, gray white myxoid, firm, with multiple rounded white translucent friable nodules ranging from 0.5 to 1.5 cms. Cut surface showed lobulated mass with areas of hemorrhage and multiple cystic spaces. Lobules were separated by delicate fibrous septae with gelatinous and translucent areas [Figure 2].
|Figure 2: Gross picture of the tumor showing gelatinous irregular areas separated by fibrous septae|
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Microscopically, the tumor showed lobules of cartilaginous areas separated by fibrous septae and areas of myxoid change. The cartilaginous areas showed haphazard arrangement of chondrocytes within the lacunae and clustering at places. Some lacunae showed two or more nuclei [Figure 3].
|Figure 3: 10´, H and E, histopathology section showing lobules of cartilaginous area composed of atypical chondrocytes|
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Few of the cells showed nuclei, which where hyperchromatic and pleomorphic. Calcification was absent. There was no evidence of osteoid or bone formation. Based on all these features, diagnosis of grade two chondrosarcoma was made.
| Discussion|| |
Cytological features of primary bone lesions have been reported as characteristic and have corresponded with histological findings in over 82% of cases in the literature. Accuracy in differentiation between benign and malignant lesions was variously reported as ranging from 95%-100% on FNAC of bone lesions, including cartilaginous tumors.  FNAC is ideally suited in lytic bone lesions of all sites except thoracic vertebra.
Cytological findings always have to be evaluated with clinical and radiological appearance as about 20% of enchondromas and grade one chondrosarcoma cases will show overlapping cytological features.
Chondrosarcoma is a malignant neoplasm derived from cartilage lineage cells. It produces an extracellular matrix that is entirely chondroid in nature.  Involvement of ribs is common in chondrosarcoma as it is in our case.
More than 90% of primary chondrosarcoma are conventional intramedullary tumors of bone. Primary juxtacortical (surface) chondrosarcoma, which was the type encountered in our case, is otherwise extremely rare. Secondary chondrosarcoma may complicate other conditions, such as osteochondroma, Ollier's disease or solitary enchondroma.
While our case was that of a conventional chondrosarcoma, special types include de-differentiated, mesenchymal and clear-cell types.
Other chondrosarcomas vary from non-metastasizing tumors to highly aggressive lethal sarcomas with a high propensity for distant metastasis.
Pain of several months' duration is a very characteristic clinical symptom and represents an important element in the differential diagnosis between malignant and benign cartilage lesions. However, in our case the patient had no complaint of pain.
Radiographically, chondrosarcoma is said to present as an area of radiolucency that frequently contains punctuate and ring-like calcifications. Grossly, the characteristic picture of chondrosarcoma is that of a lobulated tumor composed of translucent hyaline nodules. Mineralization of the peripheral parts of these lobules typically produces a chalk-like or granular appearance. The less differentiated tumors reportedly present as soft and myxomatous lesions with areas of hemorrhage and necrosis. In our case, tumor showed no areas of calcification, necrosis or invasion into soft tissues.
Microscopically, the cartilaginous nature of the tumor is unmistakable. The tumor cells resemble normal chondrocytes and lie in the lacunar spaces embedded within hyaline cartilage matrix. Foci of myxoid change are seen with the lobulated architecture. The tumor cells are more or less uniformly distributed in the cartilaginous matrix or they form small clusters.
Based on the histological features such as nuclear atypia and cellularity, conventional chondrosarcoma is subdivided into three grades. In general, grade one chondrosarcomas are microscopically very similar to an enchondroma or normal cartilage and their diagnosis cannot be established without supporting radiologic and clinical evidence.
Grade two chondrosarcomas are characterized by increased cellularity and obvious nuclear atypia. The cells form loose clusters that vary in size. Nuclei with open chromatin pattern and distinct nucleoli are present in the majority of the cells. Binucleated cells are frequent. All chondrosarcomas with myxoid change are classified as grade two tumors. In our case, the chondrosarcoma was of grade two type.
Grade three chondrosarcomas are frankly malignant lesions with high cellularity, prominent nuclear atypia, and mitotic figures. 
Pleomorphism is not a feature of chondrosarcoma except the dedifferentiated tumors,  but well defined criteria to differentiate benign from malignant cartilaginous tumors has been laid down. 
A rich yield of many tissue fragments with variable cell content, cells with well defined cytoplasm, rounded nuclei, one to two nucleoli, binucleate forms and moderate nuclear pleomorphism separate low grade chondrosarcoma from chondroma.  High-grade tumors may show more predominance of single cells, prominent cellular and nuclear pleomorphism, and frequent mitosis.  DNA image ploidy analysis may help in the differentiation of high-grade from low-grade tumors. 
Chondrosarcoma has to be differentiated from chondroma, chondromyxoid fibroma and chondroblastic osteosarcoma.  In chondroma, the tumor cells are more sparse, chondroid matrix more abundant, cells are larger than normal chondrocytes but smaller than low-grade chondrosarcoma. 
In chondromyxoid fibroma, cells are enlarged with irregular nuclei and smudgy chromatin, but they lack the nuclear hyperchromasia and irregularity seen in chondrosarcoma. They also contain admixture of stellate, fibroblastic and giant osteoclastic cells.
High-grade chondrosarcoma shows more cellularity, little chondroid matrix and more pleomorphism. In contrast, chondrocytes were extremely pleomorphic in chondroblastic osteosarcoma. Extra-skeletal myxoid chondrosarcoma will show pale pink granular amorphous non condensed myxoid material in the background, abundant but small cytoplasm than conventional low grade chondrosarcoma.
There are very few reports of FNAC diagnosis of other chondrosarcoma variants such as mesenchymal, clear cell and de-differentiated types as they are very rarely found. 
Accurate cytological details are said to be obtained with May-Grunwald- Giemsa (MGG) stain only,  but in our case Papanicolaou stain was equally good. Moreover, in Giemsa-stained slides, we cannot distinguish myxoid from hyaline matrix. 
In conclusion, FNAC helps in the accurate preoperative diagnosis of chondrosarcoma of bone, including ribs.
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[Figure 1], [Figure 2], [Figure 3]