Practice Essentials
Elastofibroma is a rare, benign, slow-growing connective-tissue tumor that occurs most often in the subscapular area in elderly women. [1] Jarvi and Saxen [2] first described this rare entity in 1961. Elastofibroma is characterized by accumulated abnormal elastic fibers and is generally regarded as a reactive process, an unusual fibroblastic pseudotumor. [3]
Signs and symptoms
Elastofibroma dorsi is an uncommon benign soft tissue pseudotumor usually located at the lower pole of the scapula, deep to the serratus anterior, and often attached to the periosteum of the ribs; patients with elastofibroma dorsi present with a long history of swelling and, occasionally, pain and discomfort. [4] Sometimes, the swelling produces an elastofibroma as an unexpected finding in those unfamiliar with this entity. [1] As it is often bilateral, the contralateral site should be evaluated. [5] Half the patients in one series of 71 patients described a clunking sensation or a localized scapular swelling during movement. [6] It can be an uncommon cause of chest pain. [7]
This uncommon fibrous pseudotumor has also been described on the foot, hand, thigh, olecranon, GI tract, subungual, [8] trachea, dorsal spine, eye, and soft palate. [9]
Clinically, patients with elastofibromas usually present with a large, well-circumscribed tumor that most often does not adhere to the overlying skin. One case of ulceration has been described. [10] In 99% of cases, elastofibromas are located in the periscapular area, in relation to the latissimus dorsi, rhomboid, and serratus anterior muscles. [11] It may be bilateral. [12] Although usually asymptomatic, it may be associated with mild pain when moving the scapula.
Uncommon locations include the deltoid muscle, [13] ischial tuberosity, greater trochanter, olecranon, thoracic wall, foot, stomach, mediastinum, [14] orbita, cornea, and oral mucosa. [15] Occasionally, the tumor invades the surrounding tissues and becomes fixed to the underlying periosteum. Usually, the lesions are prominent and measure several centimeters in length; however, a small elastofibroma may be overlooked unless the patient is asked to move his or her arm laterally or anteriorly. Most patients with elastofibromas are asymptomatic. Only rarely do they report stiff shoulders, local pain with arm movement, and/or an annoying click with shoulder motion occur. [16] Potter et al reported an elastofibroma presenting in the oral cavity [17] ; Hsu et al described a case of elastofibroma oculi. [18]
Please see Workup.
Management
Complete local surgical excision is the treatment of choice in symptomatic patients or if malignancy cannot be excluded. [19, 20] It can be well-controlled by radical surgery. [6] Recurrence after surgery is unusual. [21] Spontaneous regression has been observed without treatment. Because malignant transformation has not been described, asymptomatic lesions need not be excised. [22] In fact, surgical resection should be limited to those who are symptomatic, as the incidence of postoperative complications is high. [23, 24] Bilateral back elastofibroma after resection of a malignant fibrous histiocytoma has been described. [25]
Because elastofibromas are benign neoplasms, no long-term follow-up care is necessary.
Pathophysiology
The etiology of elastofibroma remains unclear, although prevalence is increased in persons who perform manual labor involving the shoulder girdle. Thus, repeated trauma due to mechanical friction of the scapula against the ribs has been suggested to induce this process. This theory provides an explanation for the right-sided preponderance; however, in up to 66% of cases, the tumor is bilateral. Rarely, elastofibromas may be multiple in the same individual. [26, 27] In up to one third of cases, the patient has a family history of the tumor, suggesting a nontraumatic genetic origin. A mechanical strain-dependent reactivation of periostin and tenascin-C expression, along with elastin deposition, may account for the pathogenesis of their neoplasms. [28]
Elastofibroma may be a reactive process; its etiology remains unknown. [29] In a 2002 study, chromosomal gains were suggested as a cause for elastofibromas. Nishio et al [30] detected DNA copy number changes involving 1 or 2 chromosomes in 33% of 27 patients. The most common recurrent gains were at bands Xq12-q22 and 19. High-level amplifications and recurrent losses were not observed. No correlation was found between DNA copy number changes and elastofibroma size. It was concluded that these chromosomal regions may contain genes involved in the development of at least some elastofibromas. Genomic alterations were documented in 2 cases, with losses detected on 1p, 13q, 19p, and 22q by array-based comparative genomic hybridization (aCGH). [29]
Coexistence of an elastofibroma with a high-grade spindle cell sarcoma [31] and a high-grade leiomyosarcoma [32] has been reported. Moreover, because a number of other entities, including lipomas, metastases, sarcomas, and extra-abdominal fibromatoses and hemangiomas, may occur on the back and in the subscapular site, the diagnosis must be confirmed with biopsy. [33]
Cytogenetic chromosomal instability and some recurrent or clonal chromosomal changes have raised the possibility that the lesion represents a neoplastic process. [3] Recent findings suggest that CD34-positive mesenchymal cells are an integral component of elastofibroma, presumably representing a clonal fibrous proliferation. [34]
Etiology
The histogenesis of the morphologically unique elastic fibers is controversial. Note particularly that the elastinophilic structure may result from elastotic degeneration of collagen. Recent immunohistochemical, ultrastructural, and biochemical investigations have shown that the elastinophilic material is composed of elastic fibers with only a slight difference in the amino acid composition. This elastic material possibly derives from an abnormal process of elastogenesis rather than representing degenerative changes in collagen or elastic fibers themselves.
Epidemiology
Frequency
Elastofibromas are rare. Elastofibromas are often mistaken for malignant tumors because of their size and location deep to the periscapular muscles. An orthopedic oncology database of 17,500 patients showed 15 patients with elastofibroma dorsi, 12 men and 3 women, with a mean age at diagnosis of 68.4 years and a range of 51-79 years. [4]
In another study, 1,751 patients were evaluated with (18)fludeoxyglucose (FDG) – positron emission tomography (PET)/CT scanning, which detected 29 cases of elastofibroma dorsi as an incidental finding, giving a prevalence of 1.66%. [35]
The prevalence of elastofibroma dorsi was determined in another study, which found 36 incidentally on 4435 chest CT scans at a tertiary care center, representing 0.8% of elderly patients. [36]
Sex and age
Of persons affected by elastofibromas, 93% are female.
Elastofibromas occur most often in elderly women but have been reported in persons aged 35-94 years.
Prognosis
Mortality rates are unknown for elastofibroma. Morbidity is not expected.
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Elastofibroma. Hematoxylin and eosin stain. Intermediate magnification. Courtesy of Soca1zim, via Wikimedia Commons.
