Excerpt from Elastofibroma

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Background

Elastofibroma is a rare, benign, slow-growing connective-tissue tumor that occurs most often in the subscapular area in elderly women. Jarvi and Saxen¹ first described this rare entity in 1961. It is characterized by accumulated abnormal elastic fibers and is generally regarded as a reactive process, an unusual fibroblastic pseudotumor.²

Pathophysiology

The etiology of this tumor 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 are multiple in the same individual.³ In up to one third of cases, the patient has a family history of the tumor, suggesting a nontraumatic genetic origin.

In a 2002 study, chromosomal gains have been speculated as a cause for the development of elastofibromas. Nishio et al⁴ 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. The authors concluded that these chromosomal regions may contain genes involved in the development of at least some elastofibromas.

Coexistence of an elastofibroma with a high-grade spindle cell sarcoma⁵ and a high-grade leiomyosarcoma⁶ 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.

Cytogenetic chromosomal instability and some recurrent or clonal chromosomal changes have raised the possibility that the lesion represents a neoplastic process.² Recent findings suggest that CD34-positive mesenchymal cells are an integral component of elastofibroma, presumably representing a clonal fibrous proliferation.⁷

Frequency

United States

Elastofibromas are rare.

International

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.⁸

Mortality/Morbidity

Mortality rates are unknown. Morbidity is not expected.

Sex

Of persons affected, 93% are female.

Age

Elastofibromas occur most often in elderly women but have been reported in persons aged 35-94 years.

Please click here to view the full topic text: Elastofibroma