Orthopedic Oncology cases multiple myeloma

A 36-year-old female is referred to your office by her primary care physician. She

has been complaining of progressive left knee pain and stiffness for the past 5 months, and an x-ray ordered by her PCP shows a lesion in the distal femur. Biopsy demonstrates a giant cell tumor of bone.

All of the following radiographic characteristics are consistent with giant cell tumor except:

A. These lesions arise in the metaphysis and can extend into the epiphysis to subchondral bone, crossing the physeal scar

B. Bone scan can be negative in approximately 30% of giant cell tumors

C. Giant cell tumor of bone can destroy the cortex and extend into the surrounding soft tissues, without maintaining a thin peripheral rim of bone

D. When involving the spine, they are located in the anterior vertebral body

 

Discussion

The correct answer is (B). Giant cell tumor demonstrates increased uptake on bone scan. Multiple myeloma is a case where bone scan can be falsely negative in up to 20% to 30% of cases. Giant cell tumors are eccentrically located, radiolucent lesions in the metaphysis and epiphysis of long bones that can extend to the subchondral surface with loss of a peripheral rim of bone. MRI is helpful in defining the extent of soft-tissue involvement. They are found in the anterior vertebral body when involving the spine.

Which of the following is true regarding the pathogenesis of giant cell tumor?

A. Giant cells secrete RANK ligand, which activates both the stromal cells and the neighboring osteoclasts to resorb bone

B. Recurrence rate and long-term results are similar whether local adjuvant or bone graft only is applied to curetted cavity

C. Benign metastasizing giant cell tumor commonly metastasizes to local and regional lymph nodes

D. The stromal cells represent the neoplastic cell in this lesion

 

Discussion

The correct answer is (D). The pathogenesis of giant cell tumor involves the secretion of RANK ligand by stromal cells, which in turn activates giant cells which possess the RANK receptor, to increase bone resorption. Denosumab, an anti-RANK ligand antibody which blocks this RANK–RANK ligand interaction, has been approved for use in treatment of this tumor. After extended curettage with high-

speed burr, a local adjuvant such as hydrogen peroxide, sterile water, or liquid nitrogen has been shown to decrease the local recurrence rate. Rarely, giant cell tumor spreads hematogenously to the lungs, called benign pulmonary metastases, but is not known to metastasize to local or regional lymph nodes.

 

Objectives: Did you learn...?

 

Clinical features and pathogenesis of giant cell tumor of bone?

 

CASE                               17                               

A 62-year-old, African-American male is seen by his primary care physician. He complains of progressive soreness in his right hip, left thigh, and left proximal humerus.

What is the most common primary malignant bone tumor?

A. Osteosarcoma

B. Multiple myeloma

C. Giant cell tumor of bone

D. Chondrosarcoma

 

Discussion

The correct answer is (B). Multiple myeloma is a neoplastic proliferation of plasma cells producing a monoclonal protein. It is the most common primary malignancy of bone and commonly affects patients over 40 years old. It is also nearly twice as prevalent in African Americans when compared to Caucasians.

What are the common laboratory findings in multiple myeloma?

A. Normochromic, normocytic anemia, mildly elevated ESR, and hypercalcemia

B. Elevated white blood cell count, positive urine culture

C. Hypocalcemia and hyperphosphatemia

D. Abnormal iron studies and thyroid studies

 

Discussion

The correct answer is (A). Laboratory signs of multiple myeloma can include normochromic, normocytic anemia due to replacement of normal bone marrow by malignant plasma cells, an elevated ESR, and hypercalcemia secondary to osteoclast-mediated bone resorption at the sites of the multiple lytic areas

throughout the skeleton. In addition to osteoclastogenesis that is mediated by RANKL, IL-6, and macrophage inflammatory protein-1α, osteoblastic activity is also suppressed by TNF and Dickkopf-1 (Dkk-1).

1. Rays are taken which reveal multiple sites of disease.Which of the following X-Rays (Fig. 8–23A–D) demonstrates a lesion most characteristic of myeloma?

    

   Figure 8–23 A–B

    

    

    

   Figure 8–23 C–D

    

   Discussion

   The correct answer is Figure (B). On radiographs the classic apprearance of multiple myeloma is described as multiple punched out lytic lesions throughout the skeleton. Although there is a large lucent lesion in the intertrochanteric region of Figure A, the borders of this lesion are more well defined than one would expect for myeloma. The Xray in figure B shows multiple small punched out lesions

   particularly in the distal diaphysis that are characteristic of myeloma. Figure C had a sclerotic rim which is more consistent with a benign tumor. Figure D represents a blastic lesion which is more consistent with a prostate or breast metastasis. Skeletal survey is the screening tool of choice to evaluate for other areas of concern, since bone scan may be negative in multiple myeloma. This is due to the minimal osteoblastic response in myeloma.

    

   Objectives: Did you learn...?

    

   Clinical features, and radiology of multiple myeloma?