Bilateral elastofibroma dorsi - a typical case

Clinical History

A 72-year-old woman presented with a history of bilateral subscapular masses for more than five years. She denied pain or enlargement of masses during the last months, but complained of some limitation during abduction of the left shoulder.
On physical examination, the masses showed a rubber-like consistency, were grossly rounded and adhesive to deep structures.

Imaging Findings

T1, T2 and T1-weighted sequences with gadolinium administration were performed and revealed the presence of two masses located deeper to the latissimus dorsi, rhomboid and anterior serratus and inferior to the tip of both scapulas.

Both masses revealed lenticular shape, no capsule and shared the same imaging characteristics: isointensity to muscle in T1, T2-weighted images with some streaks of tissue which revealed higher intensity in both sequences, similar to fat. A heterogeneous low level of enhancement in T1-weighted sequence with gadolinium was also seen.

Discussion

Elastofibroma dorsi is a benign soft tissue lesion, most commonly seen in the subscapular region of the chest wall. Less frequent locations are ischiadic tuberosity, olecraneus and chest wall [1].
Although the aetiology is not clear, some authors state that it is a pseudotumour, reactive to mechanical friction of the scapula against the ribs during heavy manual labour.
It is more frequent in women and bilateral in 10-66% of reported cases [1]. When it is unilateral, it is thought to be more common on the right side, presumably related to the side of the patient’s dominant handedness.
More than half of the patients are asymptomatic. The other half usually report local pain or snapping scapula during flection or abduction.
The best method of diagnosis is magnetic resonance imaging. On MRI, the signal intensity is similar to the muscle on both T1- and T2-weighted images, interlaced with streaks of tissue with signal intensity of fat. Heterogeneous enhancement following gadolinium administration can be seen. The areas of increased signal intensity correspond to adipose tissue within the lesion whereas the areas of relatively decreased signal intensity correspond to areas of dense fibrous connective tissue [2].
On CT, elastofibroma is typically a poorly defined, inhomogeneous soft tissue mass with attenuation similar to that of muscle, containing linear bands of fat attenuation.
The differential diagnosis of a periscapular lesion of decreased to intermediate signal intensity on both T1- and T2-weighted imaging includes lesions with decreased cellularity and abundant collagen, such as desmoid, neurofibroma, liposarcoma, aggressive fibromatosis, and malignant fibrous histiocytoma [3].
As the majority of these lesions have a characteristic appearance and location, awareness of their benign nature it is important to avoid unnecessary biopsy and surgical removal.
No reports of malignant transformation is known, so when it is asymptomatic it could be considered as a "do not touch lesion", and conservative management is suggested.
Treatment of elastofibroma dorsi is provided only in symptomatic forms or when the diagnosis is doubtful. It consists in complete surgical excision of the mass with curative marginal resection.
Recurrence only had been described in cases of incomplete excision.

Differential Diagnosis List

Final Diagnosis

Bilateral elastofibroma dorsi

URL:	https://eurorad.org/case/15695
DOI:	10.1594/EURORAD/CASE.15695
ISSN:	1563-4086