Amyopathic dermatomyositis and breast cancer: case report

Introduction: Amyopathic dermatomyositis is a chronic and rare inflammatory myopathy, whose humoral response leads to microangiopathy, muscular ischemia and dermatological alterations, exemplified by Gottron’s papules and heliotrope. The incidence of neoplasms in this pathology is approximately five to seven times higher than in the general population. The most frequent types of cancer are ovarian, breast, uterine, gastric and hepatic, which arise from a probable inadequate immune response of the organism. The treatment consists of corticosteroid therapy, hydroxychloroquine, and, in some cases, immunosuppressants. Objectives: The objective of this report is to describe the case of a patient with amyopathic dermatomyositis who developed breast cancer approximately 5 years after the diagnosis of the rheumatological condition. Methods: A case report study, based on access to the electronic and physical medical record of the patient under the care of the Rheumatology Outpatient Clinic at Emílio Carlos Hospital in Catanduva, São Paulo, Brazil. Approval protocol of the Research Ethics Committee 73463323.4.0000.5430. Results: SSC, 43 years old, female, caucasian. Since 2015, had been under the care of the Rheumatology outpatient clinic due to a diagnosis of dermatomyositis. The patient presented cutaneous vasculitis, featuring tendon exposure in the hands, in addition to Gottron’s papules and heliotrope. There was no muscular weakness present. Complementary tests were performed and neoplasms were discarded. After approximately two years, the patient evolved with Raynaud’s phenomenon and acute pulmonary involvement, identified in the computed tomography as nonidiopathic interstitial pulmonary fibrosis. Was under the regime of azathioprine 100 mg/day, hydroxychloroquine 400 mg/day, and losartan 50 mg/day. Given the clinical picture presented, required pulse therapy (methylprednisolone) and immunoglobulin, resulting in improvement of the condition and symptomatic remission. Serologies for HIV, hepatitis B and C, FTAabs, all of which were non-reactive. In November 2021, a breast biopsy was performed due to abnormalities detected in routine mammography. Maintained standard medications, but suspended hydroxychloroquine. Immunohistochemical analysis indicated the presence of invasive carcinoma in the right breast, whose histological type was invasive lobular carcinoma, multifocal, grade 2 (Nottingham), lobular carcinoma in situ present. Presence of compromised sentinel lymph node in the right armpit. The anatomopathological standing (8th edition of the Cancer Standing Manual from the American Joint Committe on Cancer): pT2(m)pN1mi(Is), which means cancer classified as T2 with microscopic spread to regional lymph nodes and intrasinusal involvement according to the TNM Staging System. Considering this, the patient underwent skin-reducing mastectomy and lymph node dissection, followed by 15 sessions of adjuvant radiotherapy and 15 sessions of chemotherapy (AC-T), which were suspended due to late breast seroma around the prosthesis. An abdominal tomography, chest X-ray, bone scintigraphy, and transvaginal ultrasound were performed to exclude other neoplasms. Presently, the patient is in use of Tamoxifen and continues to be monitored at the Rheumatology outpatient clinic. Conclusions: There is compelling evidence that supports the association between dermatomyositis and breast cancer. Therefore, patients with dermatomyositis, should be evaluated for the potential presence of concomitant malignancies, through physical examination and complementary tests, on behalf of diagnosis and early treatment.