# Elastofibroma Dorsi: An Uncommon Benign Pseudotumour

Authors: C. R. Chandrasekar; R. J. Grimer; S. R. Carter; R. M. Tillman; A. Abudu; A. M. Davies; V. P. Sumathi
Journal: Sarcoma
 (2008-02-14)

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## Abstract

Elastofibroma dorsi is an uncommon benign soft tissue pseudotumour usually located at the
lower pole of the scapula, deep to serratus anterior, and often attached to the periosteum of the ribs,
presenting with long history of swelling and occasionally pain and discomfort. This lesion is usually seen in patients over the age of 50 years and is not uncommonly mistaken as a malignant tumour because of its size and location deep to the periscapular muscles.
Review of the orthopaedic oncology database of 17 500 patients revealed that  there were
15 patients with elastofibroma dorsi. There were 12 males and 3 females, mean age at diagnosis of 68.4 years range 51–79 years. The diagnosis was confirmed by MRI in 3 patients, excision biopsy in 3 patients, trucut biopsy in 8 patients and open biopsy in 1 patient.
Eight patients had excision of the lesion which was symptomatic. There have been no recurrences. We highlight the clinical and radiological presentation of elastofibroma dorsi to increase awareness of its existence and management.


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## Body

## 1. Introduction

Elastofibroma dorsi is an uncommon benign soft
tissue pseudotumour  usually
located at the lower pole of the scapula,
deep to serratus anterior, often
attached to the periosteum of the ribs, presenting with a long history of swelling
and occasionally pain and discomfort in elderly patients. Jarvi and
Saxen [1]
first described the condition in 1959 at the 12th Congress of Scandinavian
Pathologists and subsequently published their work in 1961. They are slow-growing
tumours in the region of inferior angle of the scapula. Clinical
presentation is usually with swelling, discomfort, snapping of the scapula, and
occasionally pain. Careful radiological assessment with MRI or CT can reveal
bilateral lesions virtually assuring the diagnosis [2]. Because the pseudotumours
are deep to the deep fascia and are often more than 5 centimetres in size, then
there is a possibility of malignancy. If the lesion is unilateral, the MRI
appearance of a poorly circumscribed, heterogeneous soft tissue mass,
occasionally enhanced by gadolinium, makes it difficult to exclude a soft
tissue sarcoma with complete confidence. This necessitates the need for biopsy
to confirm the diagnosis. Often the presence of the swelling with symptoms,
albeit mild, makes patients prefer surgical excision of the swelling. There are
few case reports in the orthopaedic literature [3–6]. We describe our
experience of treating 15 patients with elastofibroma dorsi.


## 2. Materials and Methods

In a prospective database containing
details of all the referrals to our orthopaedic oncology centre for over 20
years, we identified 15 patients with a diagnosis of elastofibroma dorsi
(Table1).Table 1
Details
of 15 patients with elastofibroma dorsi.
Age at diagnosisSexSideSize (cms)Duration of symptomsBasis of diagnosisSurgeryFollow up in months71 yrMaleR66 monthsExcision biopsy277 yrMaleR76 monthsExcision biopsy151 yrMaleR52 monthsExcision biopsy165 yrMaleL1060 monthsOpen biopsyExcision2461 yrMaleB8.536 monthsTrucut biopsyExcision570 yrFemaleR1012 monthsTrucut biopsyExcision775 yrMaleR1018 monthsTrucut biopsyExcision1068 yrMaleL96 monthsTrucut biopsyExcision1967 yrMaleL848 monthsTrucut biopsyExcision276 yrMaleL103 monthsTrucut biopsyExcision279 yrMaleR93 monthsTrucut biopsyExcision266 yrFemaleR36 monthsTrucut biopsy254 yrMaleL336 monthsMRI1272 yrMaleL4.912 monthsMRI1266 yrFemaleB418 monthsMRI30There were 12 males and 3 females. The mean age
at diagnosis was 68.4 years (range 51–79 years). The
mean duration of symptoms was 20 months (range 3–60 months). It
was bilateral in 2 patients (13%). Swelling, discomfort, and occasionally pain
were the presenting symptoms. In one patient, the swelling was first noticed by
his wife. One patient was known to have symptomatic cervical spondylosis and
previous surgery for cervical rib.Clinical examination showed a firm, deep,
swelling in the infrascapular region (see, Figure1) which was fixed to the rib cage.
The swelling was not tender on palpation. The swelling was more prominent on
forward flexion of the shoulder due to the inferior angle of the scapula moving
forward.Figure 1
Arrow shows the typical location for
elastofibroma dorsi.Eight patients had a trucut
biopsy, 1 patient had an open biopsy, 3 patients had excision biopsy, and 3 patients
had their diagnosis based on clinical and MRI findings. Once the diagnosis was
confirmed, 4 patients opted for nonoperative treatment with periodic assessment
and 8 patients opted for excision of the swelling. During surgery, the swelling
was found to be deep to lattismus dorsi and serratus anterior, and it was attached to the periosteum of the ribs in the infrascapular
region. The aim of surgery was marginal excision of the swelling which was
achieved in all patients. The wounds were closed with a drain in situ, and the
drain was removed after 24–48 hours. The
patients were followed for a mean period of 8.6 months (range 1–30 months). No
patient had residual symptoms or local recurrence.


## 3. MR Imaging Findings

The lesion was anterior or caudal to the inferior pole of the scapula,
and was deep in relation to lattismus dorsi, serratus anterior, and rhomboid
muscles. It was a poorly circumscribed, unencapsulated soft tissue mass.
Bilateral imaging and contrast enhancement was not routinely performed. The appearance
of a soft tissue mass with signal intensity similar to skeletal muscle with
regions of alternating high and low signal intensities on T1 and T2 weighted
spin echo sequences in the typical subinfrascapular location was diagnostic of
elastofibroma   especially if the lesion was
bilateral (see, Figure2).Figure 2
Axial T1-weighted MR image showing an elastofibroma as a
soft tissue mass deep to the muscles and adjacent to the chest wall.


## 4. Pathology

Pathologists consider elastofibroma dorsi
as a pseudotumour or tumour-like lesion. Macroscopically, the tumour was firm
and ill-defined with a grey-white cut surface. The tumour varied in size from 3
to 10 cm. The average size was 7 cm. The tumour volume ranged from 14 to 367
cubic centimetres (average 92.5 cc). Histology showed that the tumour was hypocellular
containing a mixture of benign fibroblasts, eosinophilic collagen, and elastin
fibres. Elastin stain showed deeply staining branched and unbranched fibres
exhibiting a central dense core and serrated margins. All specimens showed
adipose tissue interspersed between the benign fibroblasts (see, Figures3,
4, 5).Figure 3
Macroscopic appearance of
elastofibroma showing greyish white fibrous areas admixed with adipose tissue.Figure 4
H&E stain showing branched and
unbranched coarse elastin fibres admixed with collagen and mature
adipose tissue (Arrow pointing at coarse branched elastin
fibre).Figure 5
Weigert’s elastin stain showing
deeply staining branched and unbranched elastin fibres, between
benign fibroblasts and adipose tissue.


## 5. Discussion

Elastofibroma dorsi is an uncommon benign lesion. Negamine et al.
[7] have
described a series of 170 patients from Okinawa. Genetic predisposition was
reported with 32% of the 170 patients having a family history of elastofibroma.
All the larger series of elastofibroma reported in the literature showed
elastofibroma was commoner in females. In our series, it was commoner in males (80%).Elastofibroma typically occurs in the subscapular or infrascapular
region. It is also reported to occur in other sites like the axilla, ischial
tuberosity, greater trochanter, posterior elbow, stomach, rectum, omentum, eye,
hand [8], and foot. The site of occurrence was in the typical infrascapular
region in our series.Malghem et al. [9] in their review article on imaging study findings in
elastofibroma dorsi noted the considerable disagreement about the need for
obtaining a biopsy. In our series, the patients presented to the soft tissue
sarcoma clinic. Trucut biopsy was performed at the time of consultation to
obtain a definitive histological diagnosis. A series of 235 autopsies by
Jarvi and  Lansimies [10] found features of elastofibroma in the subscapular thoracic fascia
in 29 of 119 (24%) females and 10 of 89 males (11%), all aged 58 or more. Giebel
et al. [11]  in a series of 100 autopsies
found elastofibroma in 13 patients—10 males and 3
females. Naylor et al. [2] reported in their series of 12 patients that the
tumour was bilateral in all the 9 patients in whom both sides of the chest was
imaged and this indicated the benign nature of the swelling eliminating the
need for biopsy.Briccoli et al. [12] reported in their series of 9 patients that the
tumour was bilateral in 3 patients (33%) and all of the 9 patients underwent
surgical excision. Vastamaki [13] reported in a series of 5 patients that the
diagnosis was clinical based on the presence of firm subscpular mass with long
history. In our series, elastofibroma was unilateral in 13 patients (87%) and
bilateral in 2 patients (13%). If there was a definitive radiological diagnosis
with typical clinical presentation in asymptomatic patients, we deferred biopsy
(3 patients).Following clinical, radiological, and/or histological diagnosis, the
patient was offered an informed choice: 11 of our patients opted for excision of the
swelling and 4 patients opted for nonoperative treatment. Elastofibroma occurs
after the 5th decade and the mean age in our series was 68.9 years consistent with
other reported series. Large (>5 cm) soft tissue swellings deep to the deep
fascia strongly raise the possibility of a soft tissue sarcoma in this age
group [14]. The average maximum dimension of the lesion was 7 cm. We had a low
threshold to biopsy these lesions unless there was great confidence based on
clinical and radiological grounds that the lesion was benign. This is reflected
by the number of biopsies in our series.The radiological and histological findings have been well described in
various papers (Naylor et al. [2], Zembsch et al.
[6], Malghem et al. [9], and
Hayes et al. [15]).Our series is the largest surgical series for this rare condition. The
question of necessity for surgery for this benign lesion in an elderly
population is legitimate. Informed choice should be offered to the patients,
for various reasons surgery may or may not be chosen by the patient. If surgery
was the preferred option, our series has shown that curative marginal resection
can be performed safely in this age group. The periscapular region is highly
vascular and the incidence of post operative haematoma should be borne in mind.
There were no reported recurrences or other complications.


## 6. Conclusion

Elastofibroma dorsi is an uncommon benign soft tissue pseudotumour
occurring in the infrascapular region of elderly patients. The size of the lesion,
location deep to the deep fascia, and attachment to the ribs suggest the
possibility of soft tissue sarcoma. Typical MRI findings especially if the
tumour is bilateral confirm benign elastofibroma. If biopsy is performed to
exclude soft tissue sarcoma, typical histological features are diagnostic of
this benign lesion. Elastofibroma dorsi can be safely treated without surgery.
If the patient chooses to have surgical excision, marginal excision of the
lesion can be performed with minimal morbidity.



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