Rotator cuff dysfunction is more common with advancing age; the prevalence of full-thickness
rotator cuff tears has been estimated at 22% in patients older than 65 years
and 51% in patients older than 80 years,
although many of these arise insidiously and remain asymptomatic. Chronic rotator
cuff insufficiency may progress to cuff tear arthropathy,
often characterized by declining active shoulder motion and dysfunction. However,
not all older patients presenting with insidious shoulder pain, weakness, and limited
mobility have a large chronic rotator cuff tear or cuff tear arthropathy. We report
on an older patient with these symptoms resulting from a large intermuscular lipoma
displacing the supraspinatus and infraspinatus muscles and compressing the suprascapular
and axillary nerves.
The patient is an active 87-year-old woman, living independently without chronic medical
problems, with chief complaint of greater than one-year history of insidious onset
and progressive dominant right shoulder pain. She had received initial conservative
treatment for rotator cuff disease elsewhere comprising nonsteroidal medications and
a subacromial space corticosteroid injection but neither of these provided any relief.
Her right shoulder pain had become severe and persistent, and interfered with sleep
and activities of daily living.
The patient appeared healthy and spry and could get on and off the examination table
independently and with ease. Palpation of the right shoulder revealed a soft mass
overlying the supraspinatus fossa and tenderness over the suprascapular notch region
but no subacromial or glenohumeral crepitance. Active right shoulder range of motion
was limited: forward elevation to 90°, abduction to 70°, external rotation to neutral,
and internal rotation to L5. Strength testing revealed an external rotation lag compared
with 4+/5 external rotation strength on the left. Deltoid and internal rotation strength
testing revealed 4+/5 strength and belly press test was normal. The patient rated
her pain as 9/10 and reported an American Shoulder and Elbow Surgeons (ASES) score
of 17/100 and 0 “yes” responses on the Simple Shoulder Test.
Plain radiographs comprising true anteroposterior radiographs in internal and external
rotation and axillary lateral views revealed no signs of chronic rotator cuff insufficiency
or glenohumeral arthrosis. Noncontrast magnetic resonance imaging (MRI) revealed a
large irregular posterior shoulder mass, with a thin capsule and without any obvious
septations or heterogeneity, extending between the supraspinatus and infraspinatus
muscles and along the scapula, consistent with an intermuscular lipoma (Fig. 1, a-c).
The mass measured 7.3 x 9.0 x 5.2 cm in craniocaudal, transverse, and anteroposterior
dimensions. The MRI demonstrated teres minor muscle atrophy but no rotator cuff tear
or tendinosis; the supraspinatus and infraspinatus muscle bellies were displaced medially
owing to a mass effect.
Representative MRI cuts demonstrating the large posterior shoulder intramuscular lipoma:
(a) Coronal proton density cut demonstrating the mediolateral extent of the intramuscular
lipoma; (b-d) Three sagittal proton density cuts from lateral to medial demonstrating
infraspinatus and supraspinatus muscle displacement.
The patient was diagnosed with a large intermuscular lipoma vs. low-grade liposarcoma
with pain and weakness attributed to compression of the axillary nerve branch to the
teres minor and the suprascapular nerve distal to the spinoglenoid notch. An oral
prednisone taper was prescribed but this provided only transient pain relief. The
patient lacked any chronic medical problems and desired definitive treatment to eliminate
the intensifying right shoulder pain that had failed multimodal conservative treatment
and to resume her independent active lifestyle. Consequently, we elected to proceed
with surgical excision of the right shoulder mass.
After the induction of general anesthesia, the patient was positioned in a modified
lateral decubitus position (Fig. 2a). A 12-cm incision was made over the posterior
shoulder mass to the deltoid fascia, from just inferior to the mid-scapular spine
directed laterally and inferiorly near the inferior border of the posterior deltoid.
The deltoid muscle was gently elevated from distal to proximal, without detaching
its origin or insertion, and the mass was identified (Fig. 2b). A circumferential
marginal dissection was performed, and the mass was excised en bloc (Fig. 2c) and
sent to pathology. The empty lateral fossae and prominent scapular spine highlighted
the medial displacement and atrophy of the infraspinatus and supraspinatus muscles
(Fig. 2d). After routine wound closure and dressing, the patient was awakened from
anesthesia, transferred to the recovery room in stable condition, and discharged home
as an outpatient.
Intraoperative photographs demonstrating (a) patient positioning in the lateral decubitus
position (note the posterior shoulder fullness); (b) posterior shoulder incision.
The mass can be seen bulging into the defect beneath the deltoid and immediately underneath
the infraspinatus muscle fascia; (c) en bloc excision of the mass; (d) empty supraspinatus
and infraspinatus fossae resulting from medial displacement of the supraspinatus and
infraspinatus muscle bellies. The arrow points to the spine of the scapula.
The mass consisted of partially encapsulated yellow fatty lobulated tissue measuring
9 cm x 11 cm x 2.5 cm (Fig. 2c) and composed of mature noninflammatory adipose tissue
consistent with a benign lipoma. The entire specimen was inked, and sectioning displayed
a yellow fatty lobulated cut that was grossly unremarkable. Figure 3 depicts the histology
on H&E staining.
Representative histology consistent with benign lipoma.
The patient’s recovery was uneventful and uncomplicated. She wore a simple sling as
needed for comfort and transitioned to using the right arm as tolerated for activities
of daily living. She enrolled in supervised physical therapy for active range of motion
and strength training and continued physical therapy and home exercises for 6 months.
Active forward elevation and abduction improved to 150° and to 110°, respectively.
Active external rotation remained at neutral and passive external rotation was to
20°. Supraspinatus and infraspinatus muscle atrophy persisted. Deltoid strength was
maintained but external rotation strength remained limited at 3/5. She rated her shoulder
pain as 3/10 and assessed her shoulder function with an ASES score of 67 and Simple
Shoulder Test of 10. She declined repeat MRI.
Lipomas are benign fatty tumors most commonly observed around the shoulder and thigh.
Deep-seated or subfascial lipomas, such as intermuscular or intramuscular lipomas,
accounting for about 2% of all lipomas
. Intermuscular and intramuscular lipomas between and within the rotator cuff muscles,
have been described. The clinical and imaging characteristics of subfascial lipomas
may resemble those of well-differentiated liposarcomas, which confounds the differential
and supports confirmatory excisional biopsy, especially in patients with symptomatic
Subfascial lipomas around either or both of the spinoglenoid and suprascapular notch
may compress the suprascapular nerve and cause weakness. Other more common causes
of suprascapular nerve entrapment include spinoglenoid and suprascapular notch morphology,
taut ligaments, bony excrescences, and ganglion cysts related to a chronic superior
or posterior labrum tear.
Our patient presented with severe pain and weakness, most likely related to compression
by the lipoma of the suprascapular nerve and axillary nerve, especially the branch
to the teres minor muscle.
Others have previously reported on patients with shoulder pain and weakness resulting
from intermuscular and intramuscular lipomas.
16, 17, 18
In some cases, the symptoms related to nerve compression, as appeared to be the case
for our patient, whereas in others, the symptoms mimicked shoulder impingement. Ferrari
et al reported on a 45-year-old man with symptoms, attributed initially to subacromial
impingement, that abated after excision of a 5-cm intramuscular supraspinatus lipoma
through an open posterior approach.
Relwani et al reported on a 52-year-old woman whose similar symptoms resolved after
excision of a 5-cm subacromial lipomatous mass compressing the rotator cuff.
Park et al reported on a 49-year-old woman with an intramuscular infraspinatus lipoma
causing subtle positional pain without obvious nerve compression.
In addition, several reports have described lipomas around either or both of the suprascapular
and spinoglenoid notch causing direct suprascapular nerve compression.
Hazrati et al reported on a 50-year-old man presenting with deltoid referred pain
and modest motion deficits. An MRI revealed a lobulated homogeneous mass at the suprascapular
notch and EMG revealed suprascapular nerve compression. Symptoms resolved after open
mass excision and suprascapular neurolysis and ligament release.
Kim et al reported on a 61-year-old man with shoulder pain and weakness suggesting
a rotator cuff tear, but with an MRI demonstrating a 9.3 x 3.2 x 4.3 cm lipomatous
mass at the spinoglenoid notch with evidence of suprascapular nerve compression. Shoulder
strength and function recovered after marginal excision and spinoglenoid notch exploration
through a posterior deltoid approach.
We chose a single-stage en bloc resection without preoperative biopsy because the
MRI demonstrated a mass with benign features. In addition, we did not obtain a right
upper extremity EMG preoperatively because it would not influence surgical decision-making
given our patient’s severe pain, shoulder weakness, and MRI findings.
Arthroscopy has been combined with open excision of subfascial shoulder lipomas to
treat concurrent shoulder pathology.
We did not entertain arthroscopy for our patient because plain radiographs, MRI, and
physical examination did not demonstrate any obvious rotator cuff disease or intra-articular
pathology. Others have raised similar concerns regarding concurrent arthroscopy.
Our 87-year-old patient is considerably older than others reported to have undergone
rotator cuff muscle lipoma excision. Despite her advanced age, she experienced chronic
severe right shoulder pain and dysfunction that were refractory to various nonoperative
treatments and chose surgery because she did not want to suffer indefinitely. Although
her improvements in comfort and function are more modest than those described elsewhere,
the improvement in pain levels from 9/10 to 3/10 and the 50-point improvement in ASES
score validate our decision to proceed with surgical excision.
This case serves as a reminder that not all older patients presenting with insidious
onset pain and weakness have symptoms related to rotator cuff tears or arthritis.
An intermuscular or intramuscular lipomatous tumor of the supraspinatus and/or infraspinatus
should be considered in the differential diagnosis of the older patient presenting
with insidious onset shoulder pain, progressive weakness, and loss of active elevation
and external rotation, especially when there is no crepitance, plain radiographs are
unremarkable, and a rotator cuff tear is not apparent by ultrasonography or MRI.
The authors, their immediate families, and any research foundations with which they
are affiliated have not received any financial payments or other benefits from any
commercial entity related to the subject of this article.