Elastofibroma dorsi, a benign soft-tissue tumor, is distinctly situated in the infrascapular or subscapular region, being bilateral close to a third of cases. On imaging, it presents as a poorly defined soft-tissue mass with CT attenuation closely resembling adjacent skeletal muscle.

Epidemiology

It is more frequently seen in older women, with a reported female predilection of 5-13:1. The estimated mean age at diagnosis is around 65-70 years.

Clinical presentation

Elastofibroma dorsi is classically located in the infrascapular regions, deep to the serratus anterior and latissimus dorsi musculature. Unilateral masses have a slight right-sided predilection, but up to 30% of elastofibromas are bilateral ⁵.

In many cases the lesions are asymptomatic. Up to 50% of patients describe localized symptoms including:

• pain, especially on movement

• sensation of clicking, snapping, or clunking of the scapula

Pathology

Elastofibroma dorsi is composed of fibrous tissue with internal fatty streaks, which accounts for its imaging appearance. It is thought that it results from recurrent friction in the area between inferior scapula and posterior chest wall ⁶.

Radiographic features

Ultrasound

Ultrasound demonstrates a well-defined multi-layered pattern of hypoechoic linear areas of fat deposition intermixed with echogenic fibroelastic tissue.

CT

These masses typically appear as poorly defined soft-tissue masses with attenuation similar to that of the adjacent skeletal muscle. They are located in the infrascapular or subscapular region.

MRI

MRI appearance matches that of the underlying pathology. The mass appears as alternating fibrous and fatty components. 

Although the borders of these masses are relatively well defined, no capsule can be identified. 

• T1

  • fibrous component: isointense to muscle

  • fatty component: high signal

• T2

  • fibrous component: isointense to muscle

  • fatty component: high signal

• T1 C+ (Gd): heterogeneous low level enhancement

Nuclear medicine

Elastofibroma dorsi frequently shows mild to moderate uptake on FDG PET-CT, which should not be misinterpreted as a malignant lesion ⁵.

Treatment

Conservative treatment with simple observation can be employed in asymptomatic cases. Surgical removal is recommended for symptomatic cases ⁷ although some advise caution due to a high incidence of complications such as symptomatic postoperative hematoma ⁹.

History and etymology

It was first described by OH Jarvi and AE Saxen in 1961 ⁸.