Eur Radiol (2010) 20: 649–658
DOI 10.1007/s00330-009-1577-1
MUSCULOSKELETAL
Alexey Surov
Michael Hainz
Hans-Jürgen Holzhausen
Dirk Arnold
Michaela Katzer
Joerg Schmidt
Rolf Peter Spielmann
Curd Behrmann
Received: 1 March 2009
Revised: 21 July 2009
Accepted: 25 July 2009
Published online: 26 August 2009
# European Society of Radiology 2009
Skeletal muscle metastases: primary tumours,
prevalence, and radiological features
Abstract Background: Although
skeletal muscles comprise nearly 50%
of the total human body mass and are
well vascularised, metastases in the
musculature are rare. The reported
prevalence of skeletal muscle metas-
tases from post-mortem studies of
patients with cancer is inconstant and
ranges from 0.03 to 17.5%. Materials
and methods: Of 5,170 patients with
metastasised cancer examined and
treated at our institution during the
period from January 2000 to December
2007, 61 patients with muscle metas-
tases (80 lesions) were identified on
computed tomography (CT). Genital
tumours (24.6%) were the most
frequent malignancies metastasising
into the skeletal musculature, followed
by gastrointestinal tumours (21.3%),
urological tumours (16.4%), and
malignant melanoma (13.1%). Other
primary malignancies were rarer,
including bronchial carcinoma (8.2%),
thyroid gland carcinoma (4.9%), and
breast carcinoma (3.3%). In 8.2%,
carcinoma of unknown primary was
diagnosed. Results: Skeletal muscle
metastases (SMM) were located in the
iliopsoas muscle (27.5%),
paravertebral muscles (25%), gluteal
muscles (16.3%), lower extremity
muscles (12.5%), abdominal wall
muscles (10%), thoracic wall muscles
(5%), and upper extremity muscles
(3.8%). Most (76.3%) of the 80 SMM
were diagnosed incidentally during
routine staging CT examinations,
while 23.7% were symptomatic.
Conclusion: Radiologically, SMM
presented with five different types of
lesions: focal intramuscular masses
(type I, 52.5% of SMM), abscess-like
intramuscular lesions (type II, 32.5%),
diffuse metastatic muscle infiltration
(type III, 8.8%), multifocal intramus-
cular calcification (type IV, 3.7%) and
intramuscular bleeding (type V, 2.5%).
Keywords Skeletal muscle
metastases
.
Prevalence
.
CT imaging
Introduction
Skeletal muscle metastases (SMM) are rare with a reported
prevalence in autopsy series of cancer patients ranging
from 0.03 to 5.6% [1–3]. However, a more thorough search
for SMM yielded a 16–17.5% prevalence in autopsy
studies [4, 5].
The prevalence of SMM in clinical or radiological series
is difficult to ascertain. Most clinical or radiological data on
SMM consist of isolated case reports or review publica-
tions and do not provide statistical evidence. Glockner et al.
reported a frequency of metastases to skeletal muscles of
1.8% [6]. The authors analysed 1,421 patients who
presented with a solitary soft-tissue mass.
A. Surov (*)
.
R. P. Spielmann
.
C. Behrmann
Department of Radiology,
Martin-Luther-University Halle-Wittenberg,
Halle, Germany
e-mail: alex.surow@medizin.uni-halle.de
M. Hainz
.
H.-J. Holzhausen
Department of Pathology,
Martin-Luther-University
Halle-Wittenberg,
Halle, Germany
D. Arnold
Department of Haematology/Oncology,
Martin-Luther-University Halle-Wittenberg,
Halle, Germany
M. Katzer
Department of Urology,
Martin-Luther-University Halle-Wittenberg,
Halle, Germany
J. Schmidt
Department of Medical Statistics and
Controlling, Martin-Luther-University
Halle-Wittenberg,
Halle, Germany