Elastofibroma: chest wall pseudotumor

Elastofibroma dorsi--differential diagnosis in chest wall tumours

Background

Elastofibromas are benign soft tissue tumours mostly of the infrascapular region between the thoracic wall, the serratus anterior and the latissimus dorsi muscle with a prevalence of up to 24% in the elderly. The pathogenesis of the lesion is still unclear, but repetitive microtrauma by friction between the scapula and the thoracic wall may cause the reactive hyperproliferation of fibroelastic tissue.

Methods

We present a series of seven cases with elastofibroma dorsi with reference to clinical findings, further clinical course and functional results after resection, as well as recurrence. Data were obtained retrospectively by clinical examination, phone calls to the patients' general practitioners and charts review. Follow-up time ranged from four months to nine years and averaged 53 months.

Results

The patients presented with swelling of the infrascapular region or snapping scapula. In three cases, the lesion was painful. The ratio men/women was 2/5 with a mean age of 64 years. The tumor sizes ranged from 3 to 13 cm. The typical macroscopic aspect was characterized as poorly defined fibroelastic soft tissue lesion with a white and yellow cut surface caused by intermingled remnants of fatty tissue. Microscopically, the lesions consisted of broad collagenous strands and densely packed enlarged and fragmented elastic fibres with mostly round shapes. In all patients but one, postoperative seroma (which had to be punctuated) occurred after resection; however, at follow-up time, no patient reported any decrease of function or sensation at the shoulder or the arm of the operated side. None of the patients experienced a relapse.

Conclusion

In differential diagnosis of soft tissue tumors located at this specific site, elastofibroma should be considered as likely diagnosis. Due to its benign behaviour, the tumor should be resected only in symptomatic patients.

Imaging study findings in elastofibroma dorsi

Elastofibroma dorsi is a tumor or pseudotumor typically located under the tip of the scapula. It is far from uncommon in older individuals. The mass contains both fibrous tissue and fatty tissue. Imaging studies can provide the definite diagnosis in many cases. Computed tomography (CT) and magnetic resonance imaging (MRI) are particularly effective, as they visualize the characteristic layered pattern of fatty tissue (low-density by CT, high-signal on T1 images and intermediate signal on T2 images by MRI) and fibrous tissue (similar to muscle in terms of density by CT and signal intensity by MRI). To a lesser extent, plain radiographs and ultrasonography identify a number of suggestive features (location and layered structure). When the lesion exhibits typical imaging features and produces no symptoms, as is usually the case, further investigations are probably unnecessary.

Subscapular elastofibroma: a reactive pseudotumor

Six cases of elastofibroma located in the subscapular region are reported. The age of the patients ranged from 45 to 71 years (mean 59.5 years). In three cases the symptoms were posterior shoulder pain with arm motion, and one of these also had a snapping scapula. Two cases had tumor prominence as the only symptom, and in one case the tumor was found accidentally while thoracotomy was being performed. On magnetic resonance imaging a nonencapsulated soft-tissue mass closely related to the thoracic wall and elevating the scapula was identified. At surgery the tumor was densely adherent to the periosteum of the ribs and the external fascia of the rib cage, and peripherally it proceeded into the loose connective tissue of the subscapular space. Local excision was performed. At follow-up 1 to 8 years after surgery no recurrence was observed, and all patients with painful lesions had complete relief of pain.

Ulcerating elastofibroma dorsi

Elastofibroma dorsi is a rare, benign tumor in elderly persons that usually occurs in the subscapular region. It represents a degenerative pseudoneoplastic process that resembles a malignant neoplasm. We report a patient with an elastofibroma dorsi of unusual size that ulcerated. This is a rare if not unique finding in elastofibroma dorsi.