IS case 502: Elastofibroma dorsi

Joseph Reis, MD

University of Rochester


Imaging Sciences URMC 2010
Publication Date: 2010-09-10

History

An 80-year-old female with hypercalcemia (Ca >12.3 mg/dL) and weight loss had an incidental finding of two subscapular masses on CT exam.

Findings

Non-contrast CT of the chest demonstrated two soft tissues masses measuring 8 cm x 3.4 cm on the right and 6.8 cm x 2 cm on the left. These masses are lenticular, homogeneous and non-encapsulated. They are adjacent to the serratus anterior muscles between the scapula and ribs.

Diagnosis

Elastofibroma dorsi

Discussion

Elastofibroma dorsi is a benign soft tissue mass commonly presenting as an incidental finding in 2% of chest CTs. Although the prevalence of this disease is as high as 25% on autopsy, the majority of lesions are undetectable on CT due to their small sizes. The disease presents more commonly in women greater than 65 years of age. Occasionally the elastofibroma will manifest as unilateral or bilateral subscapular pain and is theorized to arise from repetitive trauma.

Elastofibromas present radiographically as soft tissue attenuation masses on CT and appear heterogeneous on T1 and T2 MR sequences with variable gadolinium enhancement. Strands of fat attenuation may be present throughout the lesions and produce their heterogeneity. These masses are typically non-encapsulated and lenticular in shape. They are large, ranging in size from 3.5 cm to 10 cm in maximum axial diameter. PET-CT hypermetabolism has also been reported and should not detract from the diagnosis if other classic signs are present. Diagnosis is confirmed radiologically by their symmetric subscapular or infrascapular positions. However, the masses can present unilaterally and typically require biopsy under these circumstances. Biopsy is indicated to exclude the presence of other thoracic soft tissue tumors. The differential diagnosis includes lipomas, sacromas and metastases. Atypical locations for elastofibromas include the axilla, elbow, greater trochanter and ischial tuberosity. Biopsy is additionally warranted in these atypical locations to exclude other soft tissue tumors from the diagnosis.

The disease is benign and consists of a fibrin and elastin pseudotumor with interspersed microadipose tissue. Most patients follow an asymptomatic course, but may proceed with an elective surgical resection if the mass size grows too large and begins to cause significant discomfort.

References

  1. Ochsner JE, Sewall SA, Brooks GN, Agni R. Best cases from the AFIP: Elastofibroma dorsi. Radiographics. 2006 Nov-Dec;26(6):1873-6. PMID: 17102057
  2. Chandrasekar CR, Grimer RJ, Carter SR, et al. Elastofibroma dorsi: an uncommon benign pseudotumour. Sarcoma. 2008;2008:756565;1-4. PMID: 18382611
  3. Naylor MF, Nascimento AG, Sherrick AD, McLeod RA. Elastofibroma dorsi: radiologic findings in 12 patients. AJR Am J Roentgenol. 1996 Sep;167(3):683-7. PMID: 8751681

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