Elastophagocytosis

Elastophagocytosis refers to the phagocytosis and intracellular digestion of elastic fibers or their fragments by histiocytes or multinucleated giant cells. 

From a pathogenetic perspective, elastolysis is usually due to an imbalance between:

• the formation and organization of elastic fibers
• their enzymatic degradation, particularly by elastases and matrix metalloproteinases,
• their inhibition, for example by α₁-antitrypsin (pulmonary emphysema)
• inflammatory or immunological damage mechanisms.

Elastophagocytosis occurs particularly in diseases involving damage to or degradation of elastic fibers, such as:

• Annular elastolytic giant cell granuloma
• Actinic granuloma
• Mid-dermal elastolysis
• Anetoderma
• Granulomatous slack skin
• Extragenital lichen sclerosus

Histopathologically, fragments of elastic tissue can be detected in the cytoplasm of the phagocytosing cells; this process can be highlighted particularly clearly through elastic fiber staining. Elastophagocytosis is not a distinct clinical entity, but rather a nonspecific histological reaction pattern.

The term “elastolysis” refers, on the one hand, to a clearly definable histological phenomenon; on the other hand, it is also used to describe clinical conditions such as mid-dermal elastolysis and perifollicular elastolysis, in which this histological phenomenon is the predominant finding.

• Elastolysis refers to the breakdown or loss of elastic fibers
• Elastophagocytosis: their uptake and digestion by macrophages or giant cells
• Elastorrhexis: A clinical and histological term for degenerative changes in elastic tissue that is rarely used in medical terminology, is applied inconsistently, and is therefore considered redundant.
• Elastosis: A clinical and histological term for a congenital or acquired degeneration of the dermal collagenous connective tissue. The elastotic material (see elastosis actinica) behaves in terms of staining in the same way as the elastic fibers of the skin (hence the technical term “elastotic”). 

1. El-Khoury J et al. (2014) Elastophagocytosis: underlying mechanisms and associated cutaneous entities. J Am Acad Dermatol 70:934-944.
2. Sina B et al. (1992) Generalized elastophagocytic granuloma. Cutis 49:355-357.
3. Tronnier M (2018) Elastolysis and skin diseases with loss of elastic fibers. J Dtsch Dermatol Ges 16:183–191.
4. Valdeolivas-Casillas N et al. (2015) An unusual elastophagocytic granuloma involving the back: a possible variant of an annular elastolytic giant cell granuloma. Dermatol Online J 21:13030/qt4bm2w0vf. PMID: 25933071.