Musculoskeletal System

Skeletal Muscle - Angiectasis

Narrative
Comment:
Angiectasis is a nonproliferative lesion in which preexisting vascular spaces are dilated and prominent (Figure 1 and Figure 2). The vessels are lined by a single layer of flat endothelium in which the endothelial cells are normal in appearance, number, and size. Angiectasis is typically an incidental lesion, and its etiology and pathogenesis are often obscure.

It is important to distinguish angiectasis from a hemangioma. This can be difficult because the distinction is not always obvious and angiectatic lesions can appear in regions of hemangiomas. Hemangiomas tend to be well-circumscribed, unencapsulated masses composed of tightly packed, dilated vascular spaces that compress surrounding tissues. While the vascular spaces are lined by a single layer of well-differentiated endothelium, endothelial nuclei are typically increased in number and slightly enlarged. In general, the absence of endothelial cell proliferation and/or nuclear atypia differentiates angiectasis from a neoplastic vascular lesion. In addition, angiectasis does not typically present as a well-circumscribed mass; the dilated vascular channels often course irregularly through the tissue.
Recommendations:
When present, angiectasis should be diagnosed and assigned a severity grade.
References:

Berridge BR, Van Vleet JF, Herman E. 2013. Cardiac, vascular, and skeletal muscle systems. In: Haschek and Rousseaux’s Handbook of Toxicologic Pathology, 3rd ed (Haschek WM, Rousseaux CG, Wallig MA, Bolon B, Ochoa R, Mahler MW, eds). Elsevier, Amsterdam, 1635-1665.

Frith CH, Ward JM. 1988. Cardiovascular system. In: Color Atlas of Neoplastic and Non-neoplastic Lesions in Aging Mice. Elsevier, Amsterdam.

Greaves P, Chouinard L, Ernst H, Mecklenburg L, Pruimboom-Brees IM, Rinke M, Rittinghausen S, Thibault S, von Erichsen J, Yoshida T. 2013. Proliferative and non-proliferative lesions of the rat and mouse soft tissue, skeletal muscle, and mesothelium. J Toxicol Pathol 26(3 suppl):1S-26S.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/25035576

Hardisty JF, Elwell MR, Ernst H, Greaves P, Kolenda-Roberts H, Malarkey DE, Mann PC, Tellier PA. 2007. Histopathology of hemangiosarcomas in mice and hamsters and liposarcomas/fibrosarcomas in rats associated with PPAR agonists. Toxicol Pathol 35:928-941.

Abstract: http://www.ncbi.nlm.nih.gov/pubmed/18098039

Vahle JL, Leininger JR, Long PH, Hall DG, Ernst H. 2013. Bone, muscle, and tooth. In: Toxicologic Pathology: Nonclinical Safety Assessment (Sahota PS, Popp JA, Hardisty JF, Gopinath C, eds). CRC Press, Boca Raton, FL, 561-587.

  • Image of angiectasis in the skeletal muscle from a male B6C3F1/N mouse in a chronic study

    Skeletal muscle - Angiectasis in a male B6C3F1/N mouse from a chronic study. Note the dilated endothelial-lined vessels filled with blood.

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Skeletal muscle - Angiectasis in a male B6C3F1/N mouse from a chronic study. Note the dilated endothelial-lined vessels filled with blood.
Skeletal muscle - Angiectasis in a male B6C3F1/N mouse from a chronic study. Note the dilated endothelial-lined vessels filled with blood.
Skeletal muscle - Angiectasis in a male B6C3F1/N mouse from a chronic study (higher magnification of Figure 1). There are dilated endothelial-lined vessels filled with blood.
Skeletal muscle - Angiectasis in a male B6C3F1/N mouse from a chronic study (higher magnification of Figure 1). There are dilated endothelial-lined vessels filled with blood.

Authors

Torrie A. Crabbs, DVM, DACVP
Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC  

Reviewers

Philip H. Long, DVM, PhD, DACVP
Presiden and Senior Pathologist
Vet Path Services, Inc.
Mason, OH

Amy Brix, DVM, PhD, DACVP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC

Robert R. Maronpot, DVM, MS, MPH, DACVP, DABT, FIATP
Senior Pathologist
Experimental Pathology Laboratories, Inc.
Research Triangle Park, NC