Background/Purpose

We have previously demonstrated that fasciitis is a common lesion of dermatomyositis (DM) detectable early after disease onset by en bloc biopsy combined with magnetic resonance imaging (MRI). Furthermore, we have shown by en bloc biopsy that the fascial microvasculature, rather than intramascular microvasculature, is one of the primary sites for inflammatory cell infiltration. Serial MRI findings showed that inflammation progresses from the fascia into the muscle. These facts indicate that fasciitis may cause muscle symptoms such as myalgia even when the muscle biopsy reveals a lack of evidence of myositis. Therefore, the detection of fasciitis plays an important role in the diagnosis of DM especially in its early stage. Power Doppler ultrasonography (PDUS) is useful method for detection of inflammation and vascularity in rheumatic diseases. We examined whether fasciitis is also detectable by PDUS in patients with DM.

Methods

Five patients newly diagnosed with DM and 5 patients newly diagnosed with polymiositis (PM), who fulfilled the Bohan and Peter criteria, were recruited from the Division of Rheumatology of Jikei University Hospital in Tokyo, Japan. In this study, all patients underwent MRI, PDUS, and en bloc biopsy before treatment with prednisolone and immunosuppressive agents. The muscles were resected en bloc with the skin, subcutaneous tissue, and fascia on the site at which patients were conscious of muscle pain, weakness, or stretched a feeling and/or in which STIR and gadolinium-enhanced fat-suppressed T1-weighted MR images showed an abnormal hyperintense area as described previously (Arthritis Rheum. 2010;62:3751-9). Hematoxylin and eosin staining and immunohistochemical staining for CD31 were performed on paraffin-embedded sections.

Results

MRI showed significant fasciitis findings in 3 patients with DM, while in no patients with PM. PDUS showed abnormal stippled blood flow signals along the fascia in all patients with DM, but in no patients with PM. Fasciitis was histologically detected in 4 patients with DM, while in no patients with PM. Although fasciitis was not detected histologically in only the fifth patient with DM, there were mild perivascular inflammatory infiltrates and neovascularization along the fascia. Immunohistochemical staining for CD31 showed abnormal growth of capillaries and venules along the fascia in all patients with DM, not in any patients with PM. This suggests that PDUS did show the blood flow of neovascularity along the fascia in patients with DM.

Conclusion

Fasciitis, demonstrated histologically by en bloc biopsy, was detected by PDUS in patients with DM. Mild fasciitis undetectable by MRI can also be detected by PDUS. Our data suggests that PDUS allows early diagnosis of fasciitis associated with DM.

---

« Back to 2014 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/power-doppler-ultrasonography-for-detection-of-abnormal-fascial-vascularity-a-potential-early-diagnostic-tool-in-fasciitis-of-dermatomyositis/