The need for a biopsy in the workup of oncologic disease Figure 1. An obvious reason for biopsy before surgery would be a case like this. Here a boy of 12 presented with pain in the left knee (a). The diagnosis was osteosarcoma, which meant the boy, would lose the distal half of his thigh bone (b) with a specialized joint replacement device (c). In this case I was able to save his tibia growing zone (d). He also required to undergo chemotherapy prior to surgery. All of these factors necessitate a biopsy to be done beforehand. Figure
2. This
boy had a Ewing’s sarcoma of the proximal tibia (a). Unfortunately he had been
biopsied in a previous institution laterally which injured his common peroneal
nerve (arrow, b). The tumor was resected after chemotherapy (c). A bone
transplant was successfully performed (d). Nevertheless the nerve could not be
saved and the boy had to undergo tendon transfers to correct his foot
paralysis.
Figure 3. This patient had a tumor in the proximal fibula (a). We approached the tumor laterally (b). Exposing the tumor showed the nerve in close proximity (arrowed, c). Obviously a biopsy here is ill-advised due to contamination of the nerve.
Figure 4. This tumor appeared to be fatty on MRI(a). It was seen to surround the sciatic nerve and femoral artery (circled). A biopsy was ill-advised as the tumor was close to these vital structures, had to be taken out anyway and if biopsied would have been subject to sampling error (b). In the specimen (b), we found three different tumor types from low-grade (well-differentiated) to intermediate grade. If the biopsy had sampled the low-grade area, the tumor would have been read as a benign tumor and either left alone or resected with less radical intent. Either approach could have been deleterious for the patient.
Figure 5. This boy had a fall and fracture of the left femur (a). We saw abnormal tissue at the fracture site and sent it for biopsy. This was read as a benign cartilaginous tumor (b). The fracture was stabilized and the patient followed closely. At 2 years he developed increasing pain (c). This was confirmed on CT scan to be a recurrence (d). The tumor was resected (e) and the limb salvaged with a massive prosthetic reconstruction (f).
Figure 6. This
patient presented with a tumor in the buttocks. Preoperatively, the scans did
not show any sign of malignancy. Nerve biopsies can cause paralysis. In this
case we biopsied the tumor and it was read as normal. Two biopsy procedures
proved unhelpful. An open excisional biopsy showed it to be malignant and the
tumor was then resected en bloc with all contaminated tissue. Figure 7 (video). The case is a soft tissue sarcoma of the thigh. This presented as a tumor in the sciatic nerve which was resected intraneurally using a microscope because the clinical impression was of a nerve sheathe tumor. The patient did not have any neurological deficit and a well-centralised spot of sarcoma was found surrounded by benign tissue. Conclusions One should not take the biopsy lightly as a benign procedure as it can compromise successful limb salvage surgery. A careful consideration of all factors individualized to the specific patient is a necessary step in successful management of such cases.
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