extraossäres Plasmozytom

Ausgedehntes,

extraossäres Rezidiv eines multiplen Myeloms pleural und pelvin.

A diagnostic

approach to the mediastinal masses. a Contrast-enhanced CT scan shows a right-sided aortic arch (arrow) in an asymptomatic man with an absence of the aortic knuckle on the left. b Contrast-enhanced CT scan demonstrates a soft tissue posterior mediastinal mass (*) in a 66-year-old woman with multiple myeloma diagnosis. Note the mass effect to the descending aorta and left auricula by the mass and the bilateral pleural effusion (open arrows)

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Extraosseous myeloma refers to any manifestation of multiple myeloma where there is plasma cell proliferation outside the skeletal system. This can potentially affect any organ system and the reported disease spectrum includes:

reticuloendothelial system
- lymph nodes (considered to be most common site )
central nervous system (CNS) involvement independent of bone is thought to occur in less than 1% of multiple myeloma
- leptomeningeal involvement: considered the commonest form of CNS involvement
thorax
- lung
  - pulmonary nodules
  - interstitial infiltrates
- pleura
  - can manifest as a pleural effusion or pleural thickening
abdomen
- liver
  - thought to be most common solid organ involved in the abdomen
  - involvement of the liver can occur as diffuse sinusoidal infiltration or as distinct nodules
- mesenteric: omental masses
- pancreas
- renal involvement
  - perirenal space: a relatively common occurrence in the abdomen
    - perirenal nodules: can mimic melanoma metastases
    - perirenal soft tissue thickening
  - intrarenal lesions
other sites
- subcutaneous tissues
- skin
- breast
- testis
- orbit

Epidemiology

The overall incidence is thought to be around 5-16% of those diagnosed with myeloma . It is considered to be more common in younger patients and in those with non-secretory myeloma and IgD myeloma .

Radiographic features

Imaging features are non-specific and widely variable depending on site. The condition can mimic other pathologies.

General image interpretation guideline

When there is known background multiple myeloma, the development of focal soft tissue masses should be considered highly suspicious for extraosseous myeloma. In particular, the development of extraosseous soft tissue masses in a myeloma patient after stem cell transplantation should raise suspicion for extraosseous myeloma. It is important to know if there is more than one lesion.