Biopsy

Biopsies can be taken by:

• fine needle aspiration (FNA)

• Trucut needle biopsy

The choice of biopsy technique is guided by discussion with the radiologist as to the differential diagnosis. FNA is less invasive then an open biopsy but there is a greater possibility of not obtaining adequate or diagnostic tissue. The site of entry needs to be carefully planned, especially with open biopsies, so that the surgical biopsy tract can be excised adequately at the time of the definitive resection. Open biopsies should ideally be performed by the surgeon who will ultimately undertake the definitive operation. The incision for open biopsy is usually longitudinal and the pathology department must be informed well in advance of the biopsy being sent for examination. The radiographs and clinical findings should be discussed with the pathologist. Strict haemostasis must be achieved while taking open biopsy and if a drain is required it must exit the wound or close to the wound, in such a manner to allow excision of the drain tract during definitive surgery to prevent potential seeding.

Pathological fractures biopsy specimens can be taken at the time of internal fixation if the treatment is palliative rather than an attempt at curative resection. At the time of open biopsy in theatre, multiple specimens should be obtained especially from the margin of the lesion to improve the chances of making the correct diagnosis. Biopsy of the centre may only show necrotic tissue. It cannot be overemphasized that the clinical features of the lesion should be relayed to the histopathologist as this will make formulating a diagnosis easier.

Figure 22.49. Carcinoma of the bronchus with metastasis to the distal humerus.

Figure 22.49. Carcinoma of the bronchus with metastasis to the distal humerus.

Figure 22.50. Osteosarcoma of the distal femur.
Figure 22.51. Fibrous cortical defects of the proximal right fibia.

The mode of transport of the specimen to the laboratory should be discussed with the histopathologist. Some specimens can be transported fresh to the laboratory and others placed in formalin which acts as a preservative and fixing agent. Frozen sections may be performed on soft-tissue

Figure 22.52. Isotope bone scan of osteosarcoma of the distal femur.

tumours but are not generally absolutely diagnostic. It is difficult to perform frozen sections on bone biopsies as they need to be decalcified first which may take a week.

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