Dermatomyositis Resolution after Neoadjuvant Therapy in HER2 Positive Breast Cancer: A Case Study

Cristina Elena Biță⁽¹⁾, Bogdan Ionel Vătu⁽²⁾, Andreea Cristina Manafu⁽³⁾, Ștefan Cristian Dinescu^(1,*), Sineta Cristina Firulescu⁽³⁾, Beatrice Andreea Trașcă⁽⁴⁾, Andreea Lili Bărbulescu⁽⁵⁾, Florentin Ananu Vreju⁽¹⁾

1)Department of Rheumatology, University of Medicine and Pharmacy of Craiova, Craiova, Romania
2)Department of Oncology, Emergency County Hospital Craiova, Craiova, Romania
3)Department of Rheumatology, Emergency County Hospital Craiova, Craiova, Romania
4)Medical Center Ecomed Research Craiova, Craiova, Romania
5)Department of Pharmacology, University of Medicine and Pharmacy of Craiova, Craiova, Romania

Background. Dermatomyositis (DM) is a rare disease that belongs to the idiopathic inflammatory myopathies, and is characterized by inflammation and weakness of proximal skeletal muscles, accompanied by skin rash.Furthermore, DM can manifest clinically as a paraneoplastic syndrome in patients with breast cancer. Managing the progression of DM is typically achievable with elevated doses of glucocorticoids in the majority of cases. Nonetheless, when faced with a severe manifestation of the paraneoplastic syndrome, initiation of cancer treatment is imperative.
Methods. We report a clinical case of 34-year-old female, presenting heliotrope rash and Gottron’s papules. In addition, there was a development of severe proximal muscle weakness with severe dysphagia and dysphonia. The clinical features and laboratory results led to the diagnosis of DM. Concomitantly, the patient was diagnosed with a stage IV M1 HEP, HER2 positive breast neoplasm.
Results. At first, high dose of glucocorticosteroids was administered as pulse therapy due to the severe symptoms of the paraneoplastic syndrome. Then anti-HER molecular targeted-therapy and chemotherapy were applied, as well as oral glucocorticoids for DM control. The patient showed significant improvement following three months of treatment, both in clinical and biological aspects.
Conclusion. This case report underscores the importance of recognizing dermatomyositis in adults as a paraneoplastic syndrome associated with underlying malignancies.

Keywords: paraneoplastic dermatomyositis, breast cancer, idiopathic inflammatory myopathy, autoantibodies

Corresponding author(s): Ștefan Cristian Dinescu, Department of Rheumatology, University of Medicine and Pharmacy Craiova, 2 Petru Rareş Street, 200349 Craiova, Romania; e-mail: dinescu.stef@gmail.com