Elastofibroma

Definition

• Fibrous mass characterized by beaded elastic fibers, generally infrascapular

Alternate / Historical Names

• Elastofibroma dorsi
• Elastofibroma scapulae

Diagnostic Criteria

• Nearly always infrascapular
  • Located deep to latissimus dorsi and rhomboid muscles
  • Rarely reported from other sites including:
    • Foot, hand, arm
    • Lower back, neck
    • GI tract
• Non-circumscribed, rubbery mass
  • Does not infiltrate muscle
• Low power appearance is nondescript mixture of fibrous tissue and fat
  • Paucicellular
• Diagnostic feature is coarsely beaded aggregates and strands of elastic tissue
  • Eosinophilic on H&E stain
  • Intensely positive on elastic stain

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting: November 20, 2007

Supplemental studies

Immunohistology

Differential diagnosis

• Elastofibroma should be considered for any ill-defined mass of the posterior chest wall
• Identification of coarse, beaded strands on elastic tissue stain is definitional

Clinical

• Nearly always over 55 years
• Vast majority between chest wall and scapula
  • Located deep to latissimus dorsi and rhomboid muscles
  • Rarely reported from other sites including:
    • Foot, hand, arm
    • Lower back, neck
    • GI tract
• Slowly growing
• Markedly increased incidence in Okinawa
  • Some cases familial in Okinawa
• Cured by excision

Lists

Soft tissue "fibromas"

• Calcifying aponeurotic fibroma
• Elastofibroma
• Fibroma of tendon sheath
• Gardner-associated fibroma
• Myofibroma
• Nuchal-type fibroma
• Pleomorphic fibroma

Bibliography

• Kempson RL, Fletcher CDM, Evans HL, Henrickson MR, Sibley RS. Tumors of the Soft Tissues, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 30, 2001
• Fletcher CDM, Unni KK, Mertens F. Pathology and Genetics of Tumours of Soft Tissue and Bone, World Health Organization Classification of Tumours 2002
• Weiss SW, Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors, 4th edition, 2001
• Nagamine N, Nohara Y, Ito E.  Elastofibroma in Okinawa. A clinicopathologic study of 170 cases.  Cancer 1982 Nov 1;50(9):1794-805
• Kindblom LG, Spicer SS.  Elastofibroma. A correlated light and electron microscopic study.  Virchows Arch A Pathol Anat Histol 1982;396(2):127-40
• Hisaoka M, Hashimoto H. Elastofibroma: clonal fibrous proliferation with predominant CD34-positive cells. Virchows Arch. 2006 Feb;448(2):195-9.
• Gun BD, Bahadir B, Behzatoglu K, Gun MO, Ozdamar SO. Elastofibroma: a clinicopathologic and immunohistochemical study of seven cases and literature review.
  APMIS. 2007 Feb;115(2):115-9.
• Yamazaki K. An ultrastructural and immunohistochemical study of elastofibroma: CD 34, MEF-2, prominin 2 (CD133), and factor XIIIa-positive proliferating fibroblastic stromal cells connected by Cx43-type gap junctions. Ultrastruct Pathol. 2007 May-Jun;31(3):209-19.