Sweet's Syndrome Induced by Aromatase Inhibitor in the Treatment of Early Breast Cancer

Debora Cardoso; Andreia Coelho; Leonor Fernandes; Leonor Vasconcelos Matos; Isabel Serrano; Helena Miranda; Ana Martins

doi:10.12890/2020_001435

Sweet's Syndrome Induced by Aromatase Inhibitor in the Treatment of Early Breast Cancer

Eur J Case Rep Intern Med. 2020 Feb 7;7(3):001435. doi: 10.12890/2020_001435. eCollection 2020.

Authors

Debora Cardoso¹, Andreia Coelho¹, Leonor Fernandes¹, Leonor Vasconcelos Matos¹, Isabel Serrano², Helena Miranda¹, Ana Martins¹

Affiliations

¹ Medical Oncology Department, Hospital São Francisco Xavier, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal.
² Pathology Department, Hospital de Cascais Dr. José Almeida, Cascais, Portugal.

Abstract

Background: Breast cancer is the most commonly diagnosed cancer in women, mainly at an early stage, allowing treatment with curative intent. Aromatase inhibitors are widely used in the adjuvant treatment of oestrogen receptor-positive breast cancer, mainly in postmenopausal women. The most frequent adverse events associated with these therapies are musculoskeletal symptoms and an increased risk of bone fractures. Cutaneous adverse events have been rarely described. Sweet's syndrome can present as an idiopathic disorder in addition to being malignancy-associated or drug-induced.

Case presentation: We report the case of a 69-year old woman, diagnosed with early stage breast cancer, who underwent breast-conserving surgery, followed by adjuvant radio and endocrine treatment with letrozole 2.5 mg daily, for a foreseeable duration of 5 years. Three months after starting letrozole, she presented with sudden fever and exuberant and painful erythematous skin papules and plaques on her upper body. After a full work-up and exclusion of other potential causes, a skin biopsy confirmed the presence of dermal oedema and a diffuse neutrophilic infiltrate, suggesting Sweet's syndrome. After discontinuation of letrozole and treatment with corticosteroids, the patient fully recovered. She resumed adjuvant treatment with tamoxifen, without symptom recurrence.

Conclusions: Sweet's syndrome is a rare condition and an association with aromatase inhibitors has not been previously reported. Although its occurrence has already been observed in the onset of malignancies such as breast cancer, aromatase inhibitors must be added to the list of potential causes of drug-induced Sweet's syndrome.

Learning points: Aromatase inhibitors are widely used in the treatment of breast cancer and, though infrequent, it is important to recognize possible cutaneous adverse events.Sweet's syndrome is a rare but troublesome condition. Prompt recognition and management are crucial to alleviate symptoms.Drug-induced Sweet's syndrome associated with aromatase inhibitors has not been previously reported and should be considered when evaluating treatment toxicities.

Keywords: Aromatase inhibitors; Sweet’s syndrome; breast cancer; cutaneous adverse events.