Paraneoplastic Dermatomyositis Associated with Endometrial Carcinoma with Calcinosis Cutis: A Case Report.

Dermatomyositis is an idiopathic inflammatory myopathy characterized by chronic muscle inflammation and pathognomonic cutaneous manifestations. It affects both adults and children and demonstrates a female predominance. Adult-onset dermatomyositis has a well-established association with malignancy and may present as a paraneoplastic syndrome, particularly in association with ovarian, lung, gastrointestinal, breast, and gynecological malignancies.

The disease typically presents with progressive symmetrical proximal muscle weakness accompanied by characteristic dermatological findings such as heliotrope rash, Gottron’s papules, shawl sign, and V-sign rash. Extramuscular involvement may include pulmonary, cardiac, ocular, and gastrointestinal manifestations. Calcinosis cutis is more common in juvenile dermatomyositis but may rarely occur in adults.

The diagnosis is established through a combination of clinical findings, elevated muscle enzymes, electromyographic abnormalities, autoantibody profiling, imaging, and occasionally muscle or skin biopsy. Early diagnosis and prompt immunosuppressive treatment are crucial in preventing long-term morbidity and improving functional outcomes.

We present a case of likely paraneoplastic dermatomyositis in a patient with previously treated endometrial carcinoma, associated with calcinosis cutis and positive myositis-specific antibodies.

A 62-year-old female from Rajasthan, a known case of Endometrial Cancer status post total abdominal hysterectomy with bilateral salpingo-oophorectomy followed by three cycles of chemotherapy and radiotherapy in 2021, presented with erythematous pruritic rash predominantly involving the face, neck, and upper chest for one year, with worsening over the preceding one month. She also developed facial puffiness during this period.

The patient complained of restricted mouth opening and progressive facial skin tightening for one year. Her husband additionally noticed frequent blinking over the past month, associated with dryness of eyes.

She also reported gradually progressive symmetrical proximal muscle weakness involving the upper limbs more than the lower limbs, associated with myalgia, leading to difficulty in raising her arms, dressing, hip flexion, and rising from a squatting position.

Additionally, she noticed a swelling measuring approximately 2 × 5 cm over the left posterior thigh for 4–5 months. Prior histopathological examination performed outside was suggestive of tumor calcinosis.

There was no history of fever, weight loss, dysphagia, arthralgia, hematuria, or Raynaud’s phenomenon.

Examination

Vital parameters were stable:

·         Pulse: 82/min

·         Blood pressure: 130/80 mmHg

·         SpO₂: 99% on room air

Systemic examination was unremarkable.

Neurological Examination

The patient was conscious and oriented. Cranial nerves were intact. Extraocular movements were full and free. No facial asymmetry, dysarthria, or dysphagia was noted.

Motor examination revealed symmetrical proximal muscle weakness:

·         Tone: Normal

·         Deep tendon reflexes: 2+ and symmetrical

·         Plantars: Bilateral flexor

·         Sensory examination: Normal

·         Cerebellar signs: Absent

·         Meningeal signs: Absent

·         Gait: Normal

Cutaneous Findings

Clinical examination revealed:

·         Heliotrope-like facial rash

·         V-sign/shawl-sign rash

·         Gottron's Papules

·         Mechanic’s digits

·         Facial skin tightening

Figure Placeholders

Figure 1. Mechanic’s Digits

Figure 2 Facial sign and v sign

Figure 3. Gottron’s Papules

Figure 4. Emg Ncv study

Figure 6. PET-CT Imaging

Investigations

Routine laboratory investigations including complete blood count, liver function tests, and renal function tests were within normal limits.

Muscle Enzymes

Additional investigations:

·         Vitamin D: 12.7 ng/mL

·         Vitamin B12: >2000 pg/mL

·         Serum ACE: 66.14 U/L

Autoimmune Workup

Considering restricted mouth opening, facial skin tightening, glossitis, and dry eyes, autoimmune evaluation was performed to rule out underlying connective tissue disease.

Imaging

Whole-body PET-CT was performed to evaluate for underlying malignancy recurrence and possible paraneoplastic association.

Histopathology

Posterior thigh swelling biopsy was suggestive of tumor calcinosis/calcinosis cutis.

Electrophysiological Study

EMG-NCS findings were suggestive of proximal inflammatory myopathy.

Management

The patient was evaluated jointly by neurology, dermatology, and ophthalmology teams.

She received:

·         Intravenous methylprednisolone pulse therapy for 3 days

·         Followed by oral prednisolone (Wysolone) 60 mg/day with gradual tapering

·         Mycophenolate mofetil initiated as a steroid-sparing agent

Ophthalmological evaluation including Schirmer’s test revealed mild tear film deficiency bilaterally without superior limbal dryness or congestion.

Supportive management included:

·         Lubricating eye drops

·         Vitamin D supplementation

·         Physiotherapy

·         Strict sun protection

·         Regular monitoring of CBC, liver function tests, renal function tests, and CPK levels

The patient demonstrated significant improvement in proximal muscle power on repeat neurological examination.

She was discharged on:

·         Prednisolone tapering regimen

Mycophenolate mofetil 250 mg twice daily for 2 weeks followed by 500 mg twice daily after laboratory reassessment

Dermatomyositis is associated with malignancy in approximately 15–25% of adult patients. The risk is particularly elevated in elderly patients and in those with dermatomyositis-associated antibodies. Gynecological malignancies including ovarian and endometrial carcinoma have been frequently associated with paraneoplastic dermatomyositis.

The present case is notable for:

•              Prior history of endometrial carcinoma

•              Characteristic cutaneous manifestations

•              Symmetrical proximal muscle weakness

•              Elevated muscle enzymes

•              Positive Mi-2 antibodies

•              Electrophysiological evidence of inflammatory myopathy

•              Presence of calcinosis cutis

Calcinosis cutis is uncommon in adult dermatomyositis and is more frequently observed in juvenile disease. Its presence in this patient adds rarity and academic significance to the case.

Mi-2 antibody positivity is generally associated with classic cutaneous manifestations and relatively favorable response to corticosteroid therapy. Early recognition and prompt initiation of immunosuppressive therapy resulted in marked clinical improvement in this patient.

This case underscores the importance of malignancy surveillance in adult-onset dermatomyositis and highlights the need for multidisciplinary management involving neurologists, dermatologists, oncologists, physiotherapists, and ophthalmologists.

This case highlights a rare presentation of likely paraneoplastic dermatomyositis associated with previously treated endometrial carcinoma, complicated by calcinosis cutis. Early diagnosis based on characteristic clinical findings, elevated muscle enzymes, antibody positivity, and electrophysiological evidence allowed timely initiation of immunosuppressive therapy with favorable response. Adult patients presenting with dermatomyositis should undergo thorough malignancy screening and long-term surveillance.

·         Adult-onset dermatomyositis has a strong association with malignancy.

·         Characteristic skin manifestations may precede muscle weakness.

·         Calcinosis cutis in adult dermatomyositis is uncommon.

·         Myositis-specific antibodies aid diagnosis and prognostication.

·         Early immunosuppressive therapy improves outcomes significantly.

·         Multidisciplinary care is essential in management.

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