Msk Dermatology · Year 2 · from Msk Dermatology

Case 3: Dermatomyositis with Occult Malignancy

Patient Presentation

Demographics: 62-year-old woman

Chief Complaint: "I have a rash on my face and hands, and I'm having trouble getting out of chairs and climbing stairs."

History of Present Illness: The patient describes 3 months of progressive weakness affecting her thighs and upper arms, making it difficult to rise from a seated position, climb stairs, and lift objects overhead. She has noticed a purple discoloration around her eyes and a rash on her hands that appeared around the same time. She reports a 15-pound unintentional weight loss over this period. She has also developed difficulty swallowing solid foods and occasionally chokes on liquids.

Past Medical History:

• Hypertension
• Hyperlipidemia
• No prior autoimmune disease

Medications:

• Amlodipine 5 mg daily
• Atorvastatin 20 mg daily (on for 3 years without issue)

Social History:

• Retired accountant
• Never smoker
• No alcohol

Family History:

• Mother had ovarian cancer at age 65

Physical Examination

• Vital Signs: BP 138/82 mmHg, HR 78 bpm, Temp 37.0C, BMI 22 kg/m2
• Skin:
• Heliotrope rash: violaceous erythema of the eyelids with periorbital edema
• Gottron papules: erythematous-to-violaceous papules over MCP and PIP joints dorsal surfaces
• V-sign: erythema over anterior neck and chest
• Shawl sign: erythema over posterior shoulders and upper back
• Periungual erythema with dilated capillary loops
• Musculoskeletal:
• Proximal muscle weakness (4/5 strength in deltoids, hip flexors)
• Difficulty rising from chair without using arms
• No muscle tenderness
• Neurologic: Normal sensation, normal reflexes

Workup and Results

Laboratory Studies:

EMG: Myopathic pattern with fibrillation potentials, positive sharp waves, early recruitment

MRI Thighs: Bilateral symmetric edema in proximal thigh musculature (quadriceps, adductors) consistent with active myositis

Muscle Biopsy: Perifascicular atrophy, perivascular inflammation with CD4+ T cells, complement deposition on capillaries - consistent with dermatomyositis

Malignancy Screening (given age and anti-TIF1-gamma positivity):

• CT chest/abdomen/pelvis: 3.5 cm ovarian mass, ascites
• CA-125: 485 U/mL (elevated)
• PET scan: Hypermetabolic ovarian mass with omental nodularity
• Gynecologic oncology consultation: Biopsy confirmed high-grade serous ovarian carcinoma

Clinical Image

Clinical photograph showing Gottron papules - erythematous to violaceous papules over the dorsal aspects of the finger joints, a pathognomonic finding in dermatomyositis. Source: Wikimedia Commons, CC BY-SA 3.0.

Diagnosis

Dermatomyositis Associated with Ovarian Carcinoma (Paraneoplastic)

Supporting Features:

• Classic dermatomyositis rash (heliotrope, Gottron papules, V-sign, shawl sign)
• Proximal muscle weakness
• Markedly elevated CK
• Myopathic EMG
• MRI showing muscle edema
• Muscle biopsy consistent with dermatomyositis
• Anti-TIF1-gamma positive (strongly associated with malignancy)
• Ovarian carcinoma diagnosed on workup

Treatment Plan

Oncologic Management (Primary):

1. Gynecologic oncology referral for staging and treatment of ovarian cancer
2. Debulking surgery planned
3. Chemotherapy (platinum-based) following surgery
4. Myositis may improve with cancer treatment

Myositis Management:

1. Prednisone: 1 mg/kg/day initially (coordinate with oncology regarding surgery timing)
2. Consider IVIG: May be added if inadequate response or if steroids problematic
3. Dysphagia management: Speech therapy evaluation, modified diet, aspiration precautions
4. Physical therapy: Maintain range of motion, gentle strengthening once inflammation controlled

Monitoring:

• CK levels to assess myositis response
• Repeat muscle strength assessment
• Monitor for aspiration pneumonia risk

Prognosis:

• Cancer-associated myositis may improve dramatically with effective cancer treatment
• Close coordination between rheumatology and oncology essential

Teaching Points

1. Dermatomyositis and malignancy: Adult DM carries 3-8 fold increased cancer risk; most common within 3 years of myositis diagnosis
2. Anti-TIF1-gamma antibodies: Strongly associated with malignancy in adult dermatomyositis; presence mandates thorough cancer screening
3. Malignancy screening: Age-appropriate screening plus CT chest/abdomen/pelvis; ovarian cancer (women) and lung cancer (both sexes) are among the most common
4. Characteristic skin findings: Heliotrope rash (pathognomonic periorbital violaceous discoloration) and Gottron papules (over dorsal finger joints) are highly specific
5. Paraneoplastic myositis: May improve or resolve with successful cancer treatment; sometimes the myositis responds better to cancer therapy than to immunosuppression alone
6. Dysphagia: Common and dangerous complication; pharyngeal and esophageal muscle involvement creates aspiration risk

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