ABSTRACT
A 49-year-old woman had been treated with adjuvant dose-dense chemotherapy for left breast cancer pT2N2aM0, Stage â ¢A. She developed a fever of over 38°C on day 13 of the third course of dose-dense doxorubicin/cyclophosphamide (AC)chemotherapy. She was started on oral levofloxacin, but the fever did not resolve. COVID-19 PCR test was positive and chest CT scan showed bilateral ground-glass opacities. She was diagnosed with COVID-19 pneumonia and hospitalized. The fever did not resolve even after sotrovimab and remdesivir were administered. On the 5th hospital day, the serum ß-D-glucan level was found to be elevated(81.7 pg/mL), and she was diagnosed with concurrent COVID-19 and Pneumocystis jirovecii pneumonia(PCP). After the start of sulfamethoxazole-trimethoprim(TMP-SMX), the fever resolved quickly. After discharge from hospital, ground-glass opacities had disappeared. She resumed dose-dense chemotherapy with TMP-SMX and completed without fever. In immunosuppressed patients with cancer drug therapy, it is necessary to make a differential diagnosis of various types of pneumonia and to consider the different types of pneumonia may occur simultaneously.