Elastofibroma Dorsi: Clinical Presentation, Imaging, and Diagnostic Pitfalls in a Geriatric Patient
Key Takeaway
Elastofibroma Dorsi is a benign soft tissue tumor often presenting as a deep infrascapular mass, commonly in elderly patients. Diagnosis relies on clinical findings like a slowly enlarging, firm mass with mechanical symptoms, confirmed by characteristic MRI and ultrasound imaging, which helps differentiate it from malignant lesions.
A 72-year-old retired construction worker presents with a 2-year history of a slowly enlarging, deep-seated left infrascapular mass. He reports a "snapping" sensation during scapular movement. On examination, there is a firm, ill-defined mass beneath the scapula. Given this clinical picture, what is your primary differential diagnosis, and how would you investigate it?
Candidate: Given the age, location, and the mechanical "snapping," the primary diagnosis is an Elastofibroma Dorsi. I would order radiographs to rule out bone pathology like an osteochondroma, and then get an MRI to confirm the diagnosis by looking for its characteristic layered signal appearance.
Failing to mention the "bilaterality" check or skipping the differential. A poor candidate might suggest an immediate incisional biopsy or fail to recognize that this is a classic "do not touch" or "biopsy with caution" lesion, potentially suggesting an aggressive workup that risks morbidity.
Start with a structured differential: Elastofibroma dorsi, soft tissue sarcoma (e.g., liposarcoma), and reactive periscapular lesions. Note the high probability of elastofibroma dorsi based on age and anatomical site. Emphasize that MRI is the gold standard, expecting a pathognomonic "fascicular/layered" signal (isointense to muscle and fat). Explicitly state the need to examine the contralateral side (bilateral in 10-66%) and note that core biopsy is often unnecessary if imaging is pathognomonic.
The MRI shows a classic layered mass as expected. The patient is symptomatic and requests removal. Describe the surgical approach, the key anatomical risks, and how you would prevent common postoperative complications.
Candidate: I would perform a marginal excision. The patient is placed prone or lateral. The approach is usually via a longitudinal or oblique incision. Key risks include injury to the dorsal scapular nerve/vessels and pleural violation. To prevent complications like seroma, I would use closed-suction drains and quilting sutures.
Over-committing to a "wide excision" (which is incorrect for a benign pseudotumor) or forgetting the "dead space" management. Ignoring the dorsal scapular nerve is a major oversight that examiners look for.
Propose a "marginal excision" preserving muscle bellies (Latissimus/Rhomboids). Highlight: 1) Nerve safety (Dorsal scapular nerve/vessels at the medial border), 2) Pleural safety (remaining superficial to intercostals), 3) Dead space management: Essential use of "quilting sutures" (tacking down flaps to the chest wall) and closed-suction drains to prevent the notorious post-op seroma. Mention the specific "chicken wing" arm position to maximize exposure.
