E1312. Extraosseous Manifestations of Multiple Myeloma
  1. Rona Orentlicher Fine; Montefiore Medical Center
  2. Marjorie Stein; Montefiore Medical Center
  3. Ellen Wolf; Montefiore Medical Center
Multiple myeloma is the most common primary adult bone neoplasm, caused by monoclonal proliferation of plasma cells within the bone marrow. Extraosseous multiple myeloma refers to plasma cell proliferation outside the skeletal system. This form of the disease is uncommon, seen in less than 5% of patients with newly diagnosed multiple myeloma and 10-30% of relapsed and refractory patients. It presents in younger patients with a mean age of 50 years old and men more frequently than women. It is an aggressive form of multiple myeloma with a very poor prognosis.

Educational Goals / Teaching Points
The goals and objectives include familiarizing residents, fellows and radiologists with the manifestations of extraosseous multiple myeloma. The correct diagnosis is crucial given its younger demographic and aggressive nature. We will discuss its features within each organ system and highlight the appropriate imaging modalities needed for a comprehensive workup.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Any organ system can potentially be involved. CT, MRI and PET/CT are the most sensitive modalities to assess for known or occult sites and to monitor treatment response. The features of the disease can be nonspecific, mimicking several other pathologies, therefore, making the proper diagnosis all the more important for appropriate treatment.

Extraosseous multiple myeloma, although uncommon, is an aggressive disease affecting younger patients and carrying a very poor prognosis, making early detection extremely important. The disease can affect any organ system. Imaging features can be non-specific, with CT, MRI and CT PET the most sensitive modalities. The presence of extraosseous lesions in a patient with multiple myeloma should raise suspicion for extraosseous disease and warrant biopsy for a definitive diagnosis.