Answer and Discussion of Quiz Set: W-003

1.    Which of the following type of tumor is usually not osteolytic and less likely to be associtated with pathologic fracture when they metastasize to bone?

A.  Prostatic adenocarcinoma.

B.  Clear cell renal cell carcinoma.

C.  Papillary carcinoma of the thyroid.

D.  Malignant melanoma.

E.  Plasmacytoma/multiple myeloma.

Answer and Discussion: The answer is (A). Metastatic prostatic adenocarcinoma tends to be osteosclerotic. All other tumors being listed here are osteolytic. In contrast to the shaft of the adult femur, the neck of the femur has a lot of bone marrow and is therefore has a much higher chance to harbour metastasis. Metastasis to this location particularly the osteolytic type of tumor is highly likely to cause pathologic fracture. Lesion in high stress areas such as the lesser trochanter more likely to cause pathologic fracture and the same is true for extensive involvement by tumor.

Further Reading:

Osteolytic metastatic tumors:http://radiopaedia.org/articles/lytic-bone-metastases

Osteosclerotic tumors: http://radiopaedia.org/articles/sclerotic-bone-metastases

Skeletal metastasis: http://www.ncbi.nlm.nih.gov/books/NBK12348/