Imaging Pearls ❯ Musculoskeletal ❯ Soft Tissue Calcification
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- “Dermatomyositis is an immune-mediated myopathic disorder that affects chiefly the proximal muscles of the extremities and, occasionally, the torso. Like polymyositis, dermatomyositis is characterized by proximal muscle weakness on physical examination and muscle edema on imaging studies.”
Thoracoabdominal Muscular Enlargement in Dermatomyositis: CT Visualization
Postolov I et al.
AJR 2005;184: S91-S93 - “Dermatomyositis is a rare, clinically and histopathologically distinct, immune-related myopathic disorder, for which a several fold increase in the risk for cancers has been established. Clinical presentation includes subacute to acute onset of proximal muscle weakness and a range of erythematous skin changes. The classic dermatologic manifestations include a heliotrope rash of the upper eyelids and Gottron's sign: bluish red plaques on the backs of the knuckles.
Dermatomyositis: CT Visualization
Postolov I et al.
AJR 2005;184: S91-S93 - “The distinctive pattern of diffuse soft tissue calcification in subcutaneous and muscular planes occurs in calcinosis universalis. The condition may be idiopathic or due to a connective tissue disorder, for example systemic lupus erythematosus, scleroderma and juvenile dermatomyositis (JDM).”
A child with skin nodules and extensive soft tissue calcification
Chauhan NS, Sharma YP
Br J Radiol. 2012 Feb; 85(1010): 193–195. - “Calcinosis universalis refers to dystrophic calcification occurring in a diffuse sheet-like manner in the fascial planes, subcutaneous tissues and muscles. It is commonly seen in association with connective tissue disease, e.g. polymyositis or dermatomyositis. .”
A child with skin nodules and extensive soft tissue calcification
Chauhan NS, Sharma YP
Br J Radiol. 2012 Feb; 85(1010): 193–195. - Patterns of Calcification with Dermatomyositis
- superficial plaques or nodules in skin and subcutaneous tissues
- deep nodular deposits extending to muscles
- deposits along fascial planes of muscles and tendons
- hard deposits covering the entire body surface. - CT of Soft Tissue Calcification
- metastatic calcification (due to hyper- or hypoparathyroidism, paraneoplastic hypercalcemia, excessive vitamin D or milk alkali syndrome),
- dystrophic calcifications in inherited disorders (Ehlers–Danlos or pseudoxanthoma elasticum)
- soft tissue tumour
- gout
- parasitic infections
- idiopathic tumoural calcinosis
- “Septic arthritis and osteomyelitis (Fig 12), pseudogout (calcium pyrophosphate deposition disease), and rheumatoid arthritis are common mimics of gout (31). Less often, malignancy, other arthritides (Fig 13), and tendinopathy (Fig 14) also may clinically imitate gout. Because of their overlapping symptoms and laboratory markers, inflammatory processes may be difficult to distinguish clinically, and they may be even more challenging to differentiate in patients with hyperuricemia or known gout elsewhere in the body. In such cases, dual-energy CT findings may be valuable in excluding urate crystal deposition, and they have been shown to help distinguish gout from inflammatory mimics such as psoriasis, rheumatoid arthritis, pseudogout, and pigmented villonodular synovitis .”
Clinical Utility of Dual-Energy CT for Evaluation of Tophaceous Gout
Deasia MA et al.
Radiographics September-October 2011 31:1365-1375 - “The gold standard for establishing a diagnosis of gout is to determine whether monosodium urate crystals are present in aspirated joint fluid or tophus. However, samples of joint fluid frequently are not obtained; in these cases, disease manifestation, serum urate levels, and radiologic findings are key to establishing a clinical diagnosis of gout (11,12). Several criteria for diagnosis have been developed over the years, including hyperuricemia, the presence of tophi or urate crystals, acute onset of painful monoarthropathy (especially at the first metatarsophalangeal joint), response to colchicine, and radiologic findings.”
Clinical Utility of Dual-Energy CT for Evaluation of Tophaceous Gout
Deasia MA et al.
Radiographics September-October 2011 31:1365-1375 - “Gout is characterized by the inflammatory response that results from the deposition of monosodium urate crystals in soft tissues and joints. Crystal deposition may lead to acute or chronic arthropathy and the formation of gouty tophi, nodular masslike aggregates of urate crystals (1). Gout is the most common crystalline type of arthropathy in the United States, and its incidence and prevalence continue to increase.”
Clinical Utility of Dual-Energy CT for Evaluation of Tophaceous Gout
Deasia MA et al.
Radiographics September-October 2011 31:1365-1375 - “Dual-energy computed tomography (CT) may be used to differentiate urate crystals from calcium by using specific attenuation characteristics, which may help diagnose gout. In patients with known tophaceous gout, dual-energy CT may be used for serial volumetric quantification of subclinical tophi to evaluate response to treatment. Given the utility of dual-energy CT in challenging cases and its ability to provide an objective outcomes measure in patients with tophaceous gout, dual-energy CT promises to be a unique and clinically relevant modality in the diagnosis and management of gout.”
Clinical Utility of Dual-Energy CT for Evaluation of Tophaceous Gout
Deasia MA et al.
Radiographics September-October 2011 31:1365-1375 - “Although diagnosing gout generally is straightforward, atypical disease may present a challenge if it is associated with unusual symptoms or sites, discordant serum urate level, or mimics of gout. Dual-energy computed tomography (CT) may be used to differentiate urate crystals from calcium by using specific attenuation characteristics, which may help diagnose gout. In patients with known tophaceous gout, dual-energy CT may be used for serial volumetric quantification of subclinical tophi to evaluate response to treatment. Given the utility of dual-energy CT in challenging cases and its ability to provide an objective outcomes measure in patients with tophaceous gout, dual-energy CT promises to be a unique and clinically relevant modality in the diagnosis and management of gout.”
Clinical Utility of Dual-Energy CT for Evaluation of Tophaceous Gout
Deasia MA et al.
Radiographics September-October 2011 31:1365-1375; - “DECT scans can produce obvious colour displays for urate deposits and help to identify subclinical tophus deposits. Furthermore, tophus volume can be measured by DECT scans through an automated volume estimation procedure.”
Dual energy computed tomography in tophaceous gout
Choi HK et al.
Ann Rheum Dis 2009;68:1609-1612 Myositis Ossificans
Heterotopic ossification following trauma (myositis ossificans traumatica) is characterized initially by the appearance of floccular calcifications approximately 3 weeks after injury. After 6-8 weeks, lamellar bone with well-defined cortex forms. Mature heterotopic ossification often demonstrates a distinctive peripheral rim of dense mineralization, the so-called "eggshell" ossification .Myositis Ossificans
Benign heterotopic ossification in the soft tissues can be seen after localized trauma, neurologic injury, or rarely, in hereditary forms such as myositis ossificans progressiva. The clinical history and distribution of the disease are important etiologic clues, with the hip, shoulder, knee, and elbow being the most commonly affected joints in the neurogenic form.- "Among reported sites of soft tissue amyloidomas, the extremities are quite rare. Amyloid tumors can mimic malignant neoplasms both clinically and radiologically."
Soft tissue amyloidoma of the extremities: a case report and review of the literature
Bardin RL et al.
Arch Pathol Lab Med 2004 Nov;128(11):1270-1273 - "Soft tissue amyloidoma of the extremities is even more uncommon and when strictly defined, only 11 such cases are reported in the English literature to date. Some have been associated with local trauma, surgery,infection, or peripheral vascular disease and a few patients have been diabetic."
Soft Tissue Amyloidoma of the Extremities: A Report of a Case and Review of the Literature
Pasternak S et al.
Am J Dermatopathol 2007 Apr;29(2):152-155 - "Amyloidoma (tumoral amyloidosis) is defined as a solitary localized tumorlike deposit of amyloid, in the absence of systemic amyloidosis. Amyloidoma of soft tissues is extremely rare and occurs mainly in the mediastinum and abdomen." Soft Tissue Amyloidoma of the Extremities: A Report of a Case and Review of the Literature
Pasternak S et al.
Am J Dermatopathol 2007 Apr;29(2):152-155 - Amyloidosis: Musculskeletal Involvement
- Amyloid arthropathy
- Diffuse marrow involvement
- Amyloidoma in/of bone
- Soft tissue amyloidoma