BONE PATHOLOGY CASE STUDIES

CASE 3 - Metastatic renal cell carcinoma

Clinical History:

This is a 55 year old male with a long smoking history. He had a recent fracture of his left proximal femur and now has pain in the right distal femur. There was no significant trauma preceding the fracture. The radiograph shows a lytic area with obvious destruction of the cortex. (Slide 3.1) A bone scan reveals multiple areas of increased uptake, indicating other lesions in other bones (a "polyostotic" problem). (Slide 3.2)
  1. What is the diagnosis?

    2. This is a metastatic lesion, not a primary bone tumor. The lytic nature of the lesions and the clear cells seen microscopically are typical of renal cell carcinoma metastases.

  2. From the history, what might have you suspected?

    3. The smoking history suggests a lung primary. Lung, breast, kidney, and prostate primaries like to go to bone. Prostate likes to make "osteoblastic" metastases. Obviously, most metastatic bone lesions are seen in adults, and most occur in central locations (not in distal extremities).

  3. What descriptive name is given to the fracture in this case?

    4. Such fractures produced by neoplasms are called "pathologic" fractures.