FIBROSARCOMA
Fibro sarcomas are classified as soft tissue sarcomas which are heterogeneous group of tumours. They mainly arise from mesenchymal tissues and have features similar to the cell type of origin.
These tumours originate in connective tissues like muscle, adipose, neurovascular, facial, fibrous tissue and are benign or malignant entities. They may arise from any anatomical site in body but skin and subcutaneous sites are most common.
All these fibro sarcomas have following features
1. They appear as pseudo encapsulated soft to firm tumours of poorly defined histologic margins
2. They are locally invasive and infiltrate through and along facial planes
3. After conservative surgical excision recurrence is common.
4. Haematogenous metastasis is up to 20% of cases but regional lymph node metastasis is unusual.
5. Metastasis depends on histopathologic grade of the tumour and resected tumour margins predict local recurrence.
6. Tumours more than(>5) cm in diameter have poor response to chemotherapy and radiation therapy.
Development of immunocytochemical procedures, the availability of monoclonal and polyclonal antibodies to various tissue markers, tissue micro array technology improved diagnosis of soft tissue sarcomas is human pathology but it is still limited degree in veterinary pathology. Usually all these tumours are graded as I, II, III, IV with ascending intensity.
Most of the fibro sarcomas arise from skin and subcutaneous tissue and represented with malignant fibroblasts. They are well differentiated and exhibit spindle shaped tumour cells with scanty cytoplasm. More anaplastic tumours show dense fibroblasts with mitosis and pleomorphism.
All fibro sarcomas tend to occur in old dogs and cats without sexual predilection.Retrieviers and Dobermans are more prone for fibro sarcomas.
All these tumours are easily diagnosed with FNAC, biopsy techniques. Routine haematological and serum biochemistry do not show any changes except anaemia and thrombocytopenia in few cases.
Modern three dimensional imaging techniques such as digital radiography, CT, MRI and ultrasonography are very useful diagnostic tools available now days and they are very useful to decide surgical approach and radiation therapy protocol.
Modified AJCC staging system is used for histological grading and clinical staging (TNM system) of fibro sarcoma.
Most of the fibro sarcomas are treated either by surgical resection, radiation and chemotherapy or suitable combination of them. Palliative radiation up to 30 to 45 GY. Is sufficient. Doxorubicin based protocols are considered as best for chemotherapy.
