Imaging Findings in Three Cases of the Nodular Type of Muscular Sarcoidosis

Abstract

Intramuscular hypoechoic well-defined nodules in young patients or patients with a history of sarcoidosis suggest the diagnosis of intramuscular sarcoid. MRI is useful in detecting muscle sarcoid, evaluating the extent and distribution of muscle involvement, and monitoring the patient during follow-up after steroid therapy. MRI showed nodules that were iso- or hyperintense relative to muscle on T1-weighted sequences. On T2-weighted images and STIR sequences, we observed numerous intramuscular nodules of homogeneous high signal intensity. All nodules enhanced homogeneously on contrast-enhanced T1-weighted sequences. Disappearance of all nodules was seen on follow-up sonograms and MR images after patients had received steroid therapy.

Musculoskeletal involvement in sarcoidosis

“…In sarcoid myopathy, three clinical patterns are generally recognized ( 37 ) : chronic myopathy (seen in 86% of cases), which is the most common form, characterized by an insidious onset of proximal muscle weakness with normal or elevated serum levels of muscle enzymes; acute myositis (seen in 11% of cases); and nodular or tumor-like myositis (seen in only 3% of cases). Nodular myopathy manifests as multiple, tumor-like, palpable nodules in the muscles.…”

“…Nodular myopathy manifests as multiple, tumor-like, palpable nodules in the muscles. ( 37 , 38 ) The use of MRI and PET/CT facilitates the diagnosis of muscle sarcoidosis.…”

“…Na miopatia sarcoide, três padrões clínicos são geralmente reconhecidos ( 37 ) : miopatia crônica (vista em 86% dos casos), que é a forma mais comum, caracterizada por um início insidioso de fraqueza muscular proximal com níveis séricos de enzimas musculares normais ou elevados; miosite aguda (vista em 11% dos casos); e miosite nodular ou tumoral (vista em apenas 3% dos casos). A miopatia nodular se manifesta como múltiplos nódulos palpáveis e tumorais nos músculos.…”

“…A miopatia nodular se manifesta como múltiplos nódulos palpáveis e tumorais nos músculos. ( 37 , 38 ) O uso da RM e da PET/TC facilita o diagnóstico de sarcoidose muscular.…”

Rapid Development of Sarcoid Tenosynovitis

“…Such nodules must be distinguished from subcutaneous intradermal sarcoid nodules 7,8 and for intramuscular sarcoid nodules. 9 The causes of an isolated, progressive tenosynovitis include sarcoidosis, rheumatoid arthritis, tuberculosis, and other infections, including atypical mycobacteria. 10,11 Histologic examination and culture would be required to definitively determine the cause.…”