macrophagic myofasciitis

A most unusual inflammatory myopathy, called "macrophagic myofasciitis", first described by the Groupe d’Etudes et Recherche sur les Maladies Musculaires Acquises et Dysimmunitaires (GERMMAD), a specific branch of the Association Française contre les Myopathies was recorded with an increasing frequency from 1993 in the main French myopathologic centers.

In October 1999, 65 "macrophagic myofasciitis" cases were recorded since our first description.

Symptoms

 myalgias (91%)
 arthralgias (68%)
 marked asthenia (55%)
 muscle weakness (45%)
 fever (32%).

Abnormal laboratory findings

 elevated CK levels (50%)
 markedly increased ESR (37%)
 myopathic EMG (35%)

Muscle biopsy

 centripetal infiltration of epimysium, perimysium, perifascicular endomysium by sheets of large cells of the monocyte/macrophage lineage (CD68+, CD1a-, S100-), with a PAS-positive content;
 absence of necrosis, of both epithelioid and giant cells, and of mitotic figures;
 presence of occasional CD8+ T-cells;
 inconspicuous muscle fibre damage.

The picture was easily distinguishable from sarcoid myopathy and fasciitis-panniculitis syndromes.

The infectious diseases could not be documented in the patients.

Patients improved under steroid therapy, associated or not with nonspecific antibiotic therapy.

References

 Macrophagic myofasciitis. Cherin P, Gherardi RK. Curr Rheumatol Rep. 2000 Jun;2(3):196-200. PMID: 11123059

 Macrophagic myofasciitis: an emerging entity. Groupe d’Etudes et Recherche sur les Maladies Musculaires Acquises et Dysimmunitaires (GERMMAD) de l’Association Française contre les Myopathies (AFM). Gherardi RK, Coquet M, Chérin P, Authier FJ, Laforêt P, Bélec L, Figarella-Branger D, Mussini JM, Pellissier JF, Fardeau M. Lancet. 1998 Aug 1;352(9125):347-52. PMID: 9717921