Orthopedic Oncology cases blastic metastases

A 59-year-old male who has not seen a physician in 10 years reports to your office for ambulatory dysfunction secondary to right hip pain. It is related to activity and has been progressive for the past 4 months, to the point where it hurts whenever he walks. He is afraid he is developing osteoarthritis and will need a total hip replacement. X-rays reveal a blastic lesion in the right proximal femur.

What is the most likely diagnosis?

1. Metastatic renal cell carcinoma

2. Paget disease

3. Metastatic prostate cancer

4. Metastatic lung cancer

 

Discussion

The correct answer is (C). In a male patient over the age of 40 with blastic bone lesions, metastatic prostate cancer is the primary diagnostic consideration. For a male, the most common primary sites that result in blastic metastases are prostate and bladder. Especially since this patient hasn’t been undergoing yearly prostate checks, his presentation is worrisome for metastatic prostate cancer.

In females, the most common primary malignancy resulting in mixed lytic and blastic bony metastases is:

1. Uterine

2. Ovarian

3. Lung

4. Breast

 

Discussion

The correct answer is (D). Breast cancer commonly develops lytic or mixed (lytic and blastic) bony metastases in females.

The patient denies history of malignancy, however, on further questioning he also reports progressive axial low back pain. Imaging is performed which demonstrates numerous spinal metastases. The presence of which anatomic structure results in a high frequency of metastatic lesions occurring in the spine?

1. Intervertebral discs

2. Batson venous plexus

3. Artery of Adamkiewicz

4. Cerebrospinal fluid

 

Discussion

The correct answer is (B). Baston venous plexus is a valveless plexus of veins around the spine that is believed to allow tumor cells easy access to the vertebral bodies.

Which of the following statements is true?

1. Lytic metastases have the same risk of fracture as blastic metastases

2. Blastic metastases have the same risk of fracture as normal bone

3. Mixed metastases are not at risk for fracture since the blastic areas strengthen the bone which cancels the effect of the lytic areas

4. Blastic metastases have a risk of pathologic fracture, but the risk is lower than lytic metastases

The correct answer is (D). Both lytic and blastic metastases can cause pathologic fracture. However, the risk is higher with lytic metastases, as demonstrated by the increased weighting in Mirel scoring system. Patients with blastic metastases and weight-bearing pain should be treated for impending fracture, in a similar fashion to patients with lytic mets.

 

Objectives: Did you learn...?

 

 

Etiology of blastic metastases in men and women? Clinical features of blastic metastases?

 

Anatomic considerations leading to metastatic bone disease?