**3. Case reports**

Three cases are included to highlight diverse and protean manifestations, also to demonstrate specific radiological investigations, with more advanced and specific tests for dermatomyositis now being available at many larger centres.

#### **3.1 Case 1**

A 17-year-old teenager was known to have dermatomyositis, having been diagnosed in 1978 at age 13. He had been treated since that time with prednisone (corticosteroid), alas, with little improvement. In 1981 he was referred for chest and pelvis X-rays, with increasing weakness, atrophy and contractures of the upper extremities. He furthermore experienced loss of strength in his legs and neck. The patient had extensive skin changes consistent with dermatomyositis and in addition was very emaciated. No clinical history of tuberculosis was elicited. The PA (posteroanterior) chest X-ray (Fig. 1a) demonstrated minimal left basal areas of opacification due to active lung disease; infective, inflammatory or due to aspiration. Hairline thickness fibrotic changes were identified in the left upper lobe due to longstanding disease, probably previous tuberculosis.

In the left supraclavicular region, the skin was noted to be retracted with soft tissue loss, and a subtle 2 cm long thin linear calcification was detected. (Fig.1b, magnified image). This finding is most suggestive of dermatomyositis, whereas the pulmonary changes are non-specific. [These images predate readily available high-resolution CT (computed tomography) of the chest.]

An AP (anteroposterior) view of the pelvis (Fig. 1c) demonstrated minimal and subtle calcification of the inner upper thighs, however, the diagnosis of dermatomyositis with multiple coarse linear calcifications overlying the outer aspect of the left iliac bone was clinched by observing this latter feature. There was an undisplaced fracture of the medial part of the left superior pubic ramus; this observation was unrelated to the known dermatomyositis.

#### **3.2 Case 2**

A 41-year-old woman with known dermatomyositis for many years (though not known whether she had had dermatomyositis as a child) was referred for radiographs of the chest, hands and thighs. She presented with cellulitis/myositis of the posterior aspect of the left

**2.7.2** Focal nodular myositis is a benign inflammatory muscle disorder, mostly affecting the thigh or lower extremity, and patients present with a painful, localised intramuscular mass. The histology of the small nodules or pseudotumours is similar to polymyositis, and the

**2.7.3** Eosinophilic myositis may present with an eosinophilic inflammatory infiltrate in

**2.7.4** Drug-related myositis may vary from acute inflammatory changes to chronic fibrosis, the latter may appear as a consequence of direct intramuscular injection of drugs in the deltoid or quadriceps muscles. Alcohol, aspirin, penicillin and sulphonamides may also lead

Three cases are included to highlight diverse and protean manifestations, also to demonstrate specific radiological investigations, with more advanced and specific tests for

A 17-year-old teenager was known to have dermatomyositis, having been diagnosed in 1978 at age 13. He had been treated since that time with prednisone (corticosteroid), alas, with little improvement. In 1981 he was referred for chest and pelvis X-rays, with increasing weakness, atrophy and contractures of the upper extremities. He furthermore experienced loss of strength in his legs and neck. The patient had extensive skin changes consistent with dermatomyositis and in addition was very emaciated. No clinical history of tuberculosis was elicited. The PA (posteroanterior) chest X-ray (Fig. 1a) demonstrated minimal left basal areas of opacification due to active lung disease; infective, inflammatory or due to aspiration. Hairline thickness fibrotic changes were identified in the left upper lobe due to

In the left supraclavicular region, the skin was noted to be retracted with soft tissue loss, and a subtle 2 cm long thin linear calcification was detected. (Fig.1b, magnified image). This finding is most suggestive of dermatomyositis, whereas the pulmonary changes are non-specific. [These images predate readily available high-resolution CT (computed

An AP (anteroposterior) view of the pelvis (Fig. 1c) demonstrated minimal and subtle calcification of the inner upper thighs, however, the diagnosis of dermatomyositis with multiple coarse linear calcifications overlying the outer aspect of the left iliac bone was clinched by observing this latter feature. There was an undisplaced fracture of the medial part of the left superior pubic ramus; this observation was unrelated to the known

A 41-year-old woman with known dermatomyositis for many years (though not known whether she had had dermatomyositis as a child) was referred for radiographs of the chest, hands and thighs. She presented with cellulitis/myositis of the posterior aspect of the left

disease may progress to a more generalised distribution typical of polymyositis.

skeletal muscle as a localised disorder, or as a generalised disease.

dermatomyositis now being available at many larger centres.

longstanding disease, probably previous tuberculosis.

to myopathic changes.

tomography) of the chest.]

dermatomyositis.

**3.2 Case 2** 

**3. Case reports** 

**3.1 Case 1** 

thigh, with a possible abscess, despite 1 week of treatment with antibiotics. A shell of curvilinear calcification was noted around the chest on the PA chest radiograph (Fig. 2a). Predominant calcification was seen of the lateral chest wall, the axillary region and within the neck, superior and parallel to the first rib, with bilateral changes. Some tramline-like calcifications were detected overlying the peripheral midzones on both sides, thereby mimicking pleural or pulmonary parenchymal disease. However, these rather coarse calcifications were situated in the superficial soft tissue and superimposed on the lung fields. No bony abnormality was observed. No cardiac or pulmonary abnormalities were detected.

Fig. 1. a.,b.,c. Case 1. A 17–year-old teenager with known dermatomyositis was referred for chest and pelvis radiographs. There is slight left based patchy opacification. Furthermore there is a minimal linear calcification of the left side of the neck (Fig. 1a,b). (Fig. 1b is a magnified image to demonstrate the calcification). The AP pelvis X-ray demonstrates extensive linear plaque-like calcification overlying the outer aspect of the left iliac bone (Fig. 1c). The radiological features correlate exactly with the clinical diagnosis of dermatomyositis.

c.

Dermatomyositis 135

Layered dense plaques of calcification were observed relating to both thighs, both in the skin and in the deeper tissues, more extensive on the left posteriorly (Fig 2c). Ultrasound examination (US) of both thighs confirmed extensive subcutaneous and intermuscular plaque-like calcifications with marked shadowing from the superficial calcifications (Fig. 2d). Within the deeper tissues of the left thigh posteriorly, a flattered tubular, anechoic area was noted, with a long fluid level and high level echoes below the level (Fig. 2e). The hyperechoic material below the level was disturbed with transducer pressure. When the examination was subsequently continued in the erect position, a shorter fluid calcium level

The above features were reported as a fluid-calcium level because of the known dermatomyositis, but as the area was tender, a localized intermuscular abscess could not be excluded. Aspiration of the lesion yielded sterile, yellowish-white fluid with the consistency of toothpaste. After aspiration the signs and symptoms relating to the left thigh resolved

d. e.

Fig. 2. d.-e. Case 2. US of the thighs again demonstrates the superficial plaques with typical shadowing consistent with calcification. Fig. 2d shows the US appearance of the right thigh. Within the deep tissue on the left side, with the patient in the prone position, a flattened anechoic area was detected with a long fluid level and high level echoes below this level,

A 46-year-old woman presented with severe proximal muscle weakness. An electromyogram demonstrated an active myopathy with neurophysiologic features of marked myopathic

The diagnosis of dermatomyositis was made due to concomitant skin changes. The patient had also had difficulty swallowing. A limited speech language therapy barium swallow was performed. No abnormality was detected, except for uncoordination and slight aspiration into the trachea (Fig. 3a). Subsequent chest radiographs and high-resolution CT of the chest

formed, along the short dimension of the collection.

and the patient made an uneventful recovery.

due to a fluid-calcium level (Fig. 2e).

changes in the right deltoid muscle.

**3.3 Case 3** 

a. b.

Fig. 2. a.-c. Case 2. A 41-year-old woman with known clinical manifestations of dermatomyositis was referred for radiographs of the chest, hands, and thighs. Ultrasound of the thighs was also performed. The PA chest X-ray demonstrates a thick shell of plaque-like calcifications within the superficial soft tissue (Fig. 2a). The PA radiograph of the hands shows more discrete and dense calcific areas, and also soft tissue loss relating to the tips of some of the fingers (Fig. 2b). Radiography of the thighs reveals multiple dense calcified plaques involving the muscles of both thighs (Fig. 2c).

c.

A PA radiograph of the hands (Fig. 2b) demonstrated a number of discrete, yet heavily calcified, foci in the soft tissue, involving both wrist areas (especially overlying the distal radius), intermetacarpal in position, and even more marked relating to the webspace between the left 1st and 2nd metacarpals. Juxtaarticular osteopaenia was noted, but no erosive articular changes were seen. Loss of soft tissue relating to the terminal tufts of the distal phalanges was detected, especially affecting the index fingers.

a. b.

c.

dermatomyositis was referred for radiographs of the chest, hands, and thighs. Ultrasound of the thighs was also performed. The PA chest X-ray demonstrates a thick shell of plaque-like calcifications within the superficial soft tissue (Fig. 2a). The PA radiograph of the hands shows more discrete and dense calcific areas, and also soft tissue loss relating to the tips of some of the fingers (Fig. 2b). Radiography of the thighs reveals multiple dense calcified

A PA radiograph of the hands (Fig. 2b) demonstrated a number of discrete, yet heavily calcified, foci in the soft tissue, involving both wrist areas (especially overlying the distal radius), intermetacarpal in position, and even more marked relating to the webspace between the left 1st and 2nd metacarpals. Juxtaarticular osteopaenia was noted, but no erosive articular changes were seen. Loss of soft tissue relating to the terminal tufts of the

Fig. 2. a.-c. Case 2. A 41-year-old woman with known clinical manifestations of

plaques involving the muscles of both thighs (Fig. 2c).

distal phalanges was detected, especially affecting the index fingers.

Layered dense plaques of calcification were observed relating to both thighs, both in the skin and in the deeper tissues, more extensive on the left posteriorly (Fig 2c). Ultrasound examination (US) of both thighs confirmed extensive subcutaneous and intermuscular plaque-like calcifications with marked shadowing from the superficial calcifications (Fig. 2d). Within the deeper tissues of the left thigh posteriorly, a flattered tubular, anechoic area was noted, with a long fluid level and high level echoes below the level (Fig. 2e). The hyperechoic material below the level was disturbed with transducer pressure. When the examination was subsequently continued in the erect position, a shorter fluid calcium level formed, along the short dimension of the collection.

The above features were reported as a fluid-calcium level because of the known dermatomyositis, but as the area was tender, a localized intermuscular abscess could not be excluded. Aspiration of the lesion yielded sterile, yellowish-white fluid with the consistency of toothpaste. After aspiration the signs and symptoms relating to the left thigh resolved and the patient made an uneventful recovery.

Fig. 2. d.-e. Case 2. US of the thighs again demonstrates the superficial plaques with typical shadowing consistent with calcification. Fig. 2d shows the US appearance of the right thigh. Within the deep tissue on the left side, with the patient in the prone position, a flattened anechoic area was detected with a long fluid level and high level echoes below this level, due to a fluid-calcium level (Fig. 2e).

#### **3.3 Case 3**

A 46-year-old woman presented with severe proximal muscle weakness. An electromyogram demonstrated an active myopathy with neurophysiologic features of marked myopathic changes in the right deltoid muscle.

The diagnosis of dermatomyositis was made due to concomitant skin changes. The patient had also had difficulty swallowing. A limited speech language therapy barium swallow was performed. No abnormality was detected, except for uncoordination and slight aspiration into the trachea (Fig. 3a). Subsequent chest radiographs and high-resolution CT of the chest

Dermatomyositis 137

f. g.

h.

dermatomyositis and dysphagia. A speech language therapy barium swallow reveals slight aspiration into the trachea (Fig. 3a). Four station STIR MRI (Fig. 3b-e) demonstrates features consistent with dermatomyositis, especially involving the shoulder girdles and trapezius muscles, the quadriceps musculature particularly the left vastus lateralis and the lateral head of the left gastrocnemius muscle. Subsequent X-ray mammography revealed a carcinoma in the superolateral quadrant of the left breast with typical minute malignant microcalcification (Fig. 3f,g). At the time of further follow-up, six years later, the patient experienced right shoulder girdle pain. No abnormality was demonstrated, except for a few

Fig. 3. a.-h. Case 3. A 46-year-old woman was referred with typical skin lesions of

small rounded superficial areas with faint rim calcification (Fig. 3h).

did not reveal an abnormality. MRI (magnetic resonance imaging) of the brain did not demonstrate any abnormal features of consequence.

d. e.

did not reveal an abnormality. MRI (magnetic resonance imaging) of the brain did not

a.

b. c.

d. e.

demonstrate any abnormal features of consequence.

f. g.

h.

Fig. 3. a.-h. Case 3. A 46-year-old woman was referred with typical skin lesions of dermatomyositis and dysphagia. A speech language therapy barium swallow reveals slight aspiration into the trachea (Fig. 3a). Four station STIR MRI (Fig. 3b-e) demonstrates features consistent with dermatomyositis, especially involving the shoulder girdles and trapezius muscles, the quadriceps musculature particularly the left vastus lateralis and the lateral head of the left gastrocnemius muscle. Subsequent X-ray mammography revealed a carcinoma in the superolateral quadrant of the left breast with typical minute malignant microcalcification (Fig. 3f,g). At the time of further follow-up, six years later, the patient experienced right shoulder girdle pain. No abnormality was demonstrated, except for a few small rounded superficial areas with faint rim calcification (Fig. 3h).

Dermatomyositis 139

Therefore, six years after the initial diagnosis of left breast cancer and dermatomyositis, no further malignant disease had been detected. The clinical and radiological features of dermatomyositis, however, had not improved, and appeared to be refractory to treatment,

**4.1.1.1** Soft tissue calcifications may be preceded by oedema of the subcutaneous tissue and muscle, causing increased muscular bulk and radiodensity, thickening of subcutaneous septa and poor definition of the subcutaneous tissue-muscle interface. These features may be detected on radiographs specifically exposed to show soft tissue to better advantage. Present day digital radiography generally shows the soft tissue far more optimally, as compared to film radiography, and even an incidental diagnosis of subtle changes of dermatomyositis may be established more readily with modern digital imaging (Fig. 3h). CT is more sensitive than MRI for demonstrating soft tissue calcifications, however, CT is rarely

**4.1.1.2** The changes are more prominent in the proximal musculature, axilla, chest wall,

**4.1.1.3** Following on effective treatment, the soft tissue oedema may decrease or disappear entirely. However, fibrosis, muscle atrophy and contractures may develop later. There tends to be decreased soft tissue and muscular bulk, increased translucency of the soft tissue,

**4.1.1.4** Soft tissue calcification occurs in 30—70% of children and 10% of adults, and may occur within the first year of the illness (Moses, 2008). The extent of calcification, especially within the muscles, appears to increase with the severity of the illness. Small or large calcareous intramuscular fascial plane calcification is distinctive of dermatomyositis and polymyositis, though subcutaneous calcification is more common. The large muscles of the proximal parts of the extremities are more frequently affected. Sheetlike confluent calcifications especially occur in the thigh (particularly the vastus lateralis) (Fig. 2c), the pelvic girdle, the upper extremity (deltoid muscles, especially), and the flexor muscles of the neck. Further areas include the elbows, knees, hands, chest and abdominal wall, axillary and

**4.1.1.5** There are four distinct patterns of soft tissue calcifications that occur in childhood dermatomyositis; deep calcareous masses, superficial calcareous masses, deep linear deposits and lacy, reticular, subcutaneous collections that encase the torso. The deep

**4.1.1.6** The amorphous calcifications of dermatomyositis should be differentiated from the bone formation in myositis ossificans, where native bone with immature trabecular bone

**4.1.1.7.1** The term 'milk of calcium' has been used to describe calcium-laden fluid collections in the gall bladder and kidney and more recently by US, in the soft tissue of the

deposits are more commonly encountered (Resnick & Kransdorf, 2005).

centrally surrounded by compact bone may be seen.

as had been shown at multiple follow-up STIR MRI.

**4. Radiographic abnormalities** 

forearms, thighs and calves (Fig. 3b-e).

osteopaenia, calcification and sometimes eventual contractures.

**4.1 Musculoskeletal system 4.1.1 Soft tissue abnormalities** 

indicated.

inguinal regions.

Four station whole body STIR (short tau inversion recovery) and T1-weighted MRI was performed on four occasions over a three year period. The later STIR MRI demonstrated more widespread low grade oedema within the muscles when compared to previous MRI. Initially the patient was treated with steroids, and later with methotrexate/plaquenil. The initial STIR MRI demonstrated marked increase in signal within the muscles of both shoulder girdles and trapezius muscles and to a lesser extent of the psoas muscles. Furthermore relatively symmetrical increased signal was noted in the quadriceps musculature, especially the left vastus lateralis. There was high signal intensity in the lateral head of the left gastrocnemius muscles. (Fig. 3b-e).

The patient had continued to be afflicted by severe dermatomyositis, with little response to treatment, and had had follow-up clinical management by the departments of rheumatology and neurology. There was concern that there might have been a concomitant underlying undetected malignancy; she had noted some tenderness of the left breast, though no lump had been palpable.

The patient was therefore referred for priority X-ray mammography and US of the breasts. Within the superolateral aspect of the left breast there was a group of dense linear casting type calcifications, but more concerning were some associated smaller, ill-defined, calcifications, the latter probably malignant. The magnification mediolateral oblique view (Fig. 3f) and craniocaudal view (Fig. 3g) demonstrated the microcalcifications to better advantage. No soft tissue mass, superficial skin thickening or retraction, or other features of malignancy were noted. US had not demonstrated a mass. Core biopsies were obtained of the calcifications under stereoradiographic guidance. The diagnosis of a carcinoma was confirmed and local excision of the tumour was performed (T1 No, grade III). Following on surgery the patient developed infective changes of the superolateral quadrant of the left breast; these resolved with antibiotic treatment.

At a later stage the clinical diagnosis of a right ischial abscess had been considered, with the right buttock having become swollen, red and painful with point tenderness. However, US had demonstrated subcutaneous induration and oedema only (as compared to the opposite side) and no abscess or collection had been detected.

CT of the chest, abdomen and pelvis had not shown metastases from the breast carcinoma or other abnormality, except for postoperative appearances of the left breast. Specifically no soft tissue calcification had been seen relating to the subcutaneous tissues or muscles.

Six years after the initial diagnosis of dermatomyositis, the patient had experienced tightness and aching of the right shoulder girdle. Radiography of the shoulder had not revealed a bony abnormality or supraspinatus tendon calcification. However, multiple, small, rounded peripherally calcified lesions had been detected especially on the axial view of the shoulder (Fig. 3h). One of the larger calcifications anterior to the shoulder had measured 6 mm in long axis. These had been thought to be due to early changes of dermatomyositis, though rather atypical in shape and configuration.

At the same time as the shoulder pain, a palpable lump had been discovered clinically in the lateral part of the right breast. MRI, before and after the intravenous administration of 20 cc of gadolinium, had demonstrated the post surgical appearances of the left breast, and in addition a very small 4 mm simple cyst within the superolateral quadrant of the right breast.

Four station whole body STIR (short tau inversion recovery) and T1-weighted MRI was performed on four occasions over a three year period. The later STIR MRI demonstrated more widespread low grade oedema within the muscles when compared to previous MRI. Initially the patient was treated with steroids, and later with methotrexate/plaquenil. The initial STIR MRI demonstrated marked increase in signal within the muscles of both shoulder girdles and trapezius muscles and to a lesser extent of the psoas muscles. Furthermore relatively symmetrical increased signal was noted in the quadriceps musculature, especially the left vastus lateralis. There was high signal intensity in the lateral

The patient had continued to be afflicted by severe dermatomyositis, with little response to treatment, and had had follow-up clinical management by the departments of rheumatology and neurology. There was concern that there might have been a concomitant underlying undetected malignancy; she had noted some tenderness of the left breast, though no lump

The patient was therefore referred for priority X-ray mammography and US of the breasts. Within the superolateral aspect of the left breast there was a group of dense linear casting type calcifications, but more concerning were some associated smaller, ill-defined, calcifications, the latter probably malignant. The magnification mediolateral oblique view (Fig. 3f) and craniocaudal view (Fig. 3g) demonstrated the microcalcifications to better advantage. No soft tissue mass, superficial skin thickening or retraction, or other features of malignancy were noted. US had not demonstrated a mass. Core biopsies were obtained of the calcifications under stereoradiographic guidance. The diagnosis of a carcinoma was confirmed and local excision of the tumour was performed (T1 No, grade III). Following on surgery the patient developed infective changes of the superolateral quadrant of the left

At a later stage the clinical diagnosis of a right ischial abscess had been considered, with the right buttock having become swollen, red and painful with point tenderness. However, US had demonstrated subcutaneous induration and oedema only (as compared to the opposite

CT of the chest, abdomen and pelvis had not shown metastases from the breast carcinoma or other abnormality, except for postoperative appearances of the left breast. Specifically no soft tissue calcification had been seen relating to the subcutaneous tissues or muscles.

Six years after the initial diagnosis of dermatomyositis, the patient had experienced tightness and aching of the right shoulder girdle. Radiography of the shoulder had not revealed a bony abnormality or supraspinatus tendon calcification. However, multiple, small, rounded peripherally calcified lesions had been detected especially on the axial view of the shoulder (Fig. 3h). One of the larger calcifications anterior to the shoulder had measured 6 mm in long axis. These had been thought to be due to early changes of

At the same time as the shoulder pain, a palpable lump had been discovered clinically in the lateral part of the right breast. MRI, before and after the intravenous administration of 20 cc of gadolinium, had demonstrated the post surgical appearances of the left breast, and in addition a very small 4 mm simple cyst within the superolateral quadrant of the right breast.

head of the left gastrocnemius muscles. (Fig. 3b-e).

breast; these resolved with antibiotic treatment.

side) and no abscess or collection had been detected.

dermatomyositis, though rather atypical in shape and configuration.

had been palpable.

Therefore, six years after the initial diagnosis of left breast cancer and dermatomyositis, no further malignant disease had been detected. The clinical and radiological features of dermatomyositis, however, had not improved, and appeared to be refractory to treatment, as had been shown at multiple follow-up STIR MRI.
