Osteosclerosing myeloma

Osteosclerosing (or osteosclerotic) myeloma is an uncommon form of multiple myeloma. It may manifest as multiple sclerotic lesions or areas of diffuse osteosclerosis. It once was considered in the same spectrum of plasma cell dyscrasias with polyneuropathy as POEMS syndrome but is now considered a separate entity..

Epidemiology

Compared with multiple myeloma, it is seen in younger patients and has a more indolent course.

Clinical features

Patients typically present with peripehral neuropathy. Bone pain is not a common feature.

Laboratory findings include:

  • thrombocytosis
  • erythrocytosis
  • hypercalcemia and renal impairment are rare compared to classical multiple myeloma

Pathology

There is usually a low percentage of plasma cells of bone marrow aspirate, compared to classical multiple myeloma where there is a high percentage. A small monoclonal protein is present which is usually IgA or IgG .

Associations

Radiographic features

The bones contain multiple sclerotic lesions but there may be mixed or purely lytic lesions as well. Diffuse osteosclerosis is rare.