Orthopedic Oncology cases biopsy

A 49-year-old female with several vertebral compression fractures presents to your office with an MRI of the spine concerning for metastatic disease. She is sent for CT of the chest, abdomen, and pelvis; whole-body bone scan; and several laboratory studies, and she returns today. CT scan and bone scan reveal several other concerning lesions, including one in the right iliac wing and left proximal humerus, but the CT fails to reveal any visceral masses. Laboratory studies are inconclusive.

What is the next best step in obtaining a diagnosis?

  1. Image-guided needle biopsy from the iliac wing lesion

  2. Open biopsy of vertebral body lesions, with decompression and fusion

  3. Seeking medical oncology consultation

  4. CT scan of the head

 

Discussion

The correct answer is (A). After appropriate imaging and laboratory studies have been conducted, an image-guided needle biopsy is indicated to achieve tissue diagnosis. Most studies document a greater than 90% yield and accuracy of guided

needle biopsies. Although in some cases of primary bone and soft-tissue neoplasms, the diagnosis may require more tissue than can be obtained from a needle biopsy. For suspected metastatic disease, it is usually an effective way of obtaining a diagnosis without significant insult to the patients overall treatment. In this case, needle biopsy may be performed at the site of iliac wing metastases, as these are fairly superficial in location. An open biopsy of the spine is a far more invasive procedure, and decompression and fusion is not indicated at this time as she has no cord compression and her primary malignancy is unknown.

Needle biopsy is performed by a musculoskeletal radiologist under CT guidance. The pathology report comes back as viable bone and cartilage, no evidence of malignancy. You suspect that the biopsy needle was in an inappropriate location, and you decide to perform an open biopsy of the iliac wing lesion. Which of the following is not a principle of open biopsy?

  1. Use of drains in line with the incision, exiting the skin close to the incision

  2. Intermuscular approach with complete exposure and protection of nearby neurovascular structures

  3. Meticulous hemostasis with electrocautery

  4. Limited longitudinal incision

 

Discussion

The correct answer is (B). While most orthopaedic operations are performed through an internervous interval, one of the principles of open biopsy is to perform the procedure in an area that can be subsequently resected to remove any contamination, which is more commonly an intramuscular approach. A limited longitudinal incision should be used, with attention paid to meticulous hemostasis. Exposure of neurovascular structures is avoided to prevent contamination of those structures. Drains are used to prevent hematoma formation and subsequent contamination.

 

Objectives: Did you learn...?

 

 

The differences between needle biopsy and open surgical biopsy? The principles of open surgical biopsy?