Document pBg0z7JBYRayrYKkodkOJXxvE
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Pictorial Essay
Extraosseous Multiple Myeloma: Imaging Features
LiaA. Moulopoulos,1
ChristineA.
and Herman I.Libshitz1
J. Granfield,1
MeletiosA.
Dimopoulos,2
E. Edmund Kim,1 Raymond Alexanian,2
Multiple myeloma is a disseminated
malignant neoplasm
usually derived from a single clone of plasma cells. Patients
with myeloma have diverse signs such as anemia, hypercalce-
mia, uremia, pathologic fractures, and recurrent Infections.
Extraosseous
manifestations
are found in less than 5% of
patients with multiple myeloma. They can arise in any tissue,
and their presence has been associated with more aggressive
disease. The purpose of this essay is to illustrate the imaging
findings of extraosseous myeloma and heighten awareness of
this unusual manifestation of multiple myeloma.
Subjects and Methods
During the past 5 years, we reviewed the imaging studies of 15 patients with extraosseous myeloma. Patients with extnaosseous myeloma in contiguity with bony involvement were excluded. Ten patients were men, and five were women (age range, 20-75 years; mean age, 49 years). More than one site of extraosseous involvement was present in i2 of 15 patients, including lymph nodes (eight patients), skin and penirenal space (four patients), liver and meninges (three patients), breast and pleura (two patients), and spleen, pancreas, neck, diaphragm, testes, lung, and omentum (one patient each). Extraskeletal tumor was proved by the presence of diffuse infiltration of monoclonal plasma cells in a tissue specimen in 22 of 33 sites of extnaosseous involvement. In 11 cases without histologic confirmation, changes in tumor size in relation to treatment for myeioma and lack of secondary disease were considered sufficient evidence of extraskeletal myelomatosis. All but three patients had received multiple courses of chemotherapy and were studied when their disease was resistant, progressive, on both.
Discussion
Extnaosseous manifestations are usually associated with a
more aggressive form of multiple myeloma that is character-
ized by increasing anaplasia of plasma cells, fever unrelated
to infection, elevated serum levels of lactate dehydrogenase,
pancytopenia, and a decreased serum level of panaprotein
[1 , 2]. This form of the disease has been termed "aggressive"
(anaplastic, undifferentiated)
myeloma and is associated
with rapid progression,
resistance to treatment, and a
median survival of 1 .5 months [1]. Aggressive myeloma is
encountered in younger patients with a mean age of 50
years; the average age of patients at diagnosis of multiple
myeloma is 60 years.
Clinicopathologic
studies have identified extnaosseous
sites of involvement in two thirds of patients with multiple
myeloma, with gross disease seen in 8-i 7% of these
patients. Direct spread from osseous disease was more fre-
quently encountered. Liver, spleen, and lymph nodes were
the most frequent distant sites of involvement in one autopsy
series [3]. In clinical series, lymph nodes, skin, lung, and
CNS have been cited most often as distant sites of extra-
osseous manifestations.
Reticuloendothellal
System
Lymph nodes were the most frequently involved extraosseous tissue in our series (Figs. 1-3). Their CT appear-
Received May 17, 1993; accepted after revision July 13, 1993. 1 Department of Diagnostic Radiology, Box 57, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030. Address con-
resrndence
to L A. Moulopoulos.
Department of Medical Oncology, The University of Texas M. D. Anderson Cancer Center, 151 5 Holcombe Blvd., Houston, TX 77030.
AJR 1993;161 :1083-1087 0361-803X/93/1615-1083
American Roentgen Ray Society
ance is similar to that of lymphoma, with multiple nodal
groups involved. In autopsy series, gross involvement of the
lymph nodes has been reported in 5% of patients with
extraosseous myeloma [1 , 3].
An enlarged spleen is an uncommon finding in patients
with myeloma; in only 0.6% of patients will the spleen extend
below the costal margin by more than 5 cm [1]. Fewer than
half the cases of enlarged spleen show tumor infiltration at
autopsy [3]. In our case, no focal lesions were detected on
CT scans, sonognams, MR images, on angiognams (Fig. 1).
Involvement of the liver occurs as diffuse sinusoidal
plasma cell infiltration and less frequently as tumor nodules
[3]. In three cases in this series, involvement of the liver was
manifested by hypovascular lesions indistinguishable
from
metastatic disease (Figs. 1 and 4).
Skin
The skin is a frequent site of extraosseous myelomatosis, which may be manifested by subcutaneous masses with a purplish hue with on without purpuna [1] (Fig. 5).
Genitourinary
System
Renal disease in multiple myeloma has several causes, and only rarely is plasma cell infiltration implicated [1]. Pennephnic nodules or masses, as seen in four of our patients, are an unusual extraosseous manifestation of myeloma that to the best of our knowledge has not been previously noported (Figs. 2 and 6). Similar findings may be seen in patients with metastatic melanoma and less often in patients with other malignant disease.
Testicular involvement in multiple myeloma is extremely uncommon, even in autopsy series. In one of our patients, involvement of both testes was proved by fine-needle aspination. MR imaging showed enlarged testes with abnormal heterogeneous signal intensity.
Meninges
CNS involvement independent of bone lesions occurs in
less than 1 % of patients with multiple myeloma. Thirty-seven
cases of diffuse infiltration of the leptomeninges
by plasma
Fig. 1-47-year-old woman with multiple
myeloma manifested by splenomegaiy,
liver
involvement, and lymphadenopathy.
She died
1 1 months after diagnosis. Biopsy was not per-
formed.
A, CT scan of abdomen shows enlarged
spleen and retroperitoneal
(arrowheads)
and
splenic hilar (arrows) lymph nodes.
B, Transverse sonogram of liver shows a
well-defined "target" lesion (arrows).
Fig. 2.-51-year-old
man with myeloma and extraosseous Involvement. Biopsy of right renal mass and aspiration of pleural fluid confirmed pres-
ence of myelomatosis.
A, Contrast-enhanced
CT scan of abdomen shows small right-sided penirenal nodule (arrows).
B, Unenhanced CT scan of abdomen obtained 7 months later shows large mass (arrows) In perirenal space indistinguishable
from right kidney.
C, CT scan of chest obtained at same time as B shows extensive adenopathy in posterior part of mediastinum, bilateral pleural effusions, and nodu-
lar pleural thickening (arrows).
AJR:161, November 1993
EXTRAOSSEOUS
Fig. 3.-43-year-old
woman with myeloma
who had jaundice 3 years after diagnosis.
Biopsy of peripancreatic
nodes showed abnor-
mal plasma cells.
A, CT scan of abdomen shows extensive
peripancreatic
adenopathy encasing hepatic ar-
tery (long arrow) and portal vein (short arrow).
Retrocrural nodes are present (arrowhead).
B, CT scan at a lower level than A shows ret-
roperitoneal adenopathy.
MULTIPLE MYELOMA
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Fig. 4.-48-year-old
man with multiple myeloma who had lytic bone
lesions and subsequently
had myelomatous
involvement of liver, lungs,
and medlastinum. Biopsy of hepatic lesions was done, and myeiomatosis
was confirmed. A, Unenhanced CT scan shows multiple low-attenuation
lesions (arrows)
in liver.
B and C, CT scan (B) and conventional radiograph (C) of chest show
nodules in both lungs.
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MOULOPOULOS
ETAL.
AJR:161, November 1993
cells have been reported [4]. Contrast-enhanced
MR imaging
is sensitive in depicting leptomeningeal
disease, although
differentiation from infectious meningitis requires clinical and
laboratory correlation (Figs. 7 and 8). An even more rare
CNS complication is an extnaaxial mass arising from the
meninges with CT and MR imaging findings similar to those
observed in patients with meningiomas (Fig. 9).
Respiratory
System
Involvement of the lung in multiple myeloma is rare and
has been reported in clinical series as a mass or infiltrate. In
our case, nodules that were indistinguishable
from meta-
stases were seen in both lungs (Fig. 4). In two cases, pleural
effusions with thickening and nodulanity of the pleura were
Fig. 5-50-year-old
man with muitiple
myeloma who had bone lesions and involve-
ment of subcutaneous tissues and lymph nodes.
Biopsy of subcutaneous
lesions showed plas-
macytosis. CT scan of abdomen shows lytic
bone lesions and two gluteal nodules (arrows).
Apparent skin thickening on left side is pro-
duced by gluteal skin crease (arrowhead).
Fig. 6-68-year-old
man with multiple myeloma who had extraosseous sites of involvement,
Including lymph nodes, diaphragm, perirenal space, and subcutaneous
tissues. He died a year
after diagnosis. No biopsy was performed.
A and B, CT scans through abdomen show a mass In left renal hilum (arrowhead in A), bilateral
perirenai nodules (arrows), and Involvement of left hemldlaphragm
(arrowhead In B).
Fig. 7.-40-year-old
man with myeloma and leptomen-
Ingeal plasmacytosis.
Contrast-enhanced
Ti -weighted
(600/20) MR Image shows leptomeningeal enhancement of
cerebeliar sulci. Cytologic analysis of CSF confirmed plas-
macytosis.
Fig. 8.-48-year-old woman with myeloma who had muitiple sites of extraosseous
involvement, including meninges, lymph nodes, omentum, and subcutaneous tissues.
Her condition deteriorated suddenly 9 months after diagnosis.
A and B, Contrast-enhanced
contiguous
axial Ti-weighted
(600/20) MR images
through upper vermis show abnormal leptomeningeal
enhancement
(white arrows).
Note epidural soft tissue arising from involvement of occipital bone (black arrows).
Cytologic analysis of CSF showed plasmacytosis.
Fig. 9.-63-year-old
man with myeloma and
Involvement of meninges, subcutaneous
tis-
sue, lymph nodes, and perirenal space.
A, Axial T2-welghted (2000/80) MR Image of
brain shows heterogeneous,
extraaxlal parietal
mass producing edema in brain parenchyma.
B, Contrast-enhanced
axial Ti-weighted
(600/20) MR image shows marked enhance-
ment of mass and meninges. A meningloma is
certainly included In differential diagnosis. surgery, mass was adherent to undersurface
At of
dura; adjacent brain and bone were intact.
I
F,
Fig. 10.-Myelomatous
involvement of pleura
in a 56-year-old
woman. Chest radiograph
shows nodular thickening of right lateral pleura,
which resolved with treatment. No biopsy was
performed.
Fig. ii .-4i -year-old woman with myeloma
and involvement of breast confirmed by biopsy.
Lateral xeromammogram
of breast shows two
well-defined lobulated plasmacytomas
(arrows).
Fig. i2.-65-year-old
woman with myeloma
manifested by a pancreatic mass. Biopsy of
mass showed plasma cell tumor. CT scan of
abdomen shows a well-demarcated,
hypervascu-
lar mass (arrows) arising from body of pancreas.
observed (Figs. 2 and 10). Extensive mediastinal adenopathy was present in one patient (Fig. 2). Involvement of the diaphragm has been reported only in autopsy series. A softtissue nodule along the crus of the hemidiaphnagm was one of the multiple sites of extnaosseous involvement in one of our patients (Fig. 6).
Breast
Few cases of plasmacytoma
of the breast have been
reported, and most of these were not associated with sys-
temic disease. Breast plasmacytomas
are solid, nontenden,
relatively well defined masses of various sizes, and they
cannot be differentiated from other solid benign or malignant
lesions on the basis of findings on clinical examination and
imaging studies (Fig. 12).
Miscellaneous
Kapadia [3] reported microscopic involvement of the pancreas in two of 60 patients in whom extnaosseous myeloma was found at autopsy. One of our patients had a plasma cell
tumor of the pancreas. A well-defined hypervasculan mass arising from the body of the pancreas was shown on CT scans, and the diagnosis of an islet cell tumor was initially considered (Fig. 12).
Involvement of the omentum was observed in one patient with end-stage multiple myeloma. The appearance was similar to lymphomatous involvement on pentoneal cancinomatosis.
Radiologists must be aware of these rare manifestations of multiple myeloma so that extensive unnecessary intervention can be avoided when extnaosseous sites of disease are encountered.
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