What are Osteolytic Lesions and Why are They Important?

What Causes Lytic Lesions in Myeloma and What Does This Mean?

Osteolytic lesion of tumor of the lower end of the radius. Sarindam7/Wikimnedia Commons/CC by 3.0

Definition: Osteolytic Lesions

Also called osteoclastic lesions or lytic lesions for short, osteolytic lesions are characteristic areas of bone damage caused by myeloma (as well as a few other conditions.)


Osteolytic lesions appear like "holes" on an x-ray.  They're commonly spoken of as having a "moth-eaten" or "punched-out" appearance.

What Causes Lytic Lesions?

There are a few ways in which myeloma works to cause these lesions.

  It can help to first describe 2 different types of cells in the bones. One type is osteoblasts. These are responsible for building bone.  The other is osteoclasts. Osteoclasts release substances that break down bone as a part of a normal process of restructuring of bone that takes place continuously in the body.

When myeloma invades bone tissue, it inhibits the osteoblasts. The activity of osteoclasts is increased at the same time. This combination of less production and more breakdown results in weak areas forming in the bone.


Lytic lesions in myeloma can be found in nearly any bone, but commonly involve the spine, the skull, the pelvis, and the rib cage.

Consequences of Bone Damage in Myeloma

Osteolytic bone lesions can cause symptoms and problems in a few different ways including:

  • Bone weakening and osteoporosis.
  • Fractures - When a fracture occurs due to a bone that is weakened from cancer it is called a pathological fracture.
  • When bones are broken down they release calcium.  The consequent elevated calcium levels in the blood, known as hypcalcemia of malignancy can lead to nausea and vomiting, weakness, muscle and joint pain, confusion, and an irregular heart rate, which can be fatal if not treated aggressively.

    Conditions/Differential Diagnosis

    There are many conditions from simple bone cysts to giant cell tumors which form single lytic lesions in the bone.

    In adults, the most common cause of multiple lytic lesions are myeloma, and metastatic breast, lung, or kidney cancers.

    Also Known As: Lytic lesions, osteoclastic lesions


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