Septic Pulmonary Embolism due to Methicillin-Resistant Staphylococcus aureus Bacteremia during Adjuvant Chemotherapy...

Septic pulmonary embolism (SPE) is a rare but serious complication in patients with cancer and is often difficult to distinguish from pulmonary metastases.

A woman in her 50s with a history of atopic dermatitis underwent left mastectomy and sentinel lymph node biopsy for hormone receptor-positive, HER2-negative breast cancer, followed by weekly adjuvant paclitaxel chemotherapy. After the seventh cycle, fever and left-sided neck pain developed. Physical examination revealed scalp folliculitis. Laboratory tests showed no leukopenia but revealed elevated C-reactive protein levels. Chest computed tomography (CT) demonstrated multiple subpleural nodules, initially suggestive of breast cancer metastasis; however, blood cultures obtained on admission yielded gram-positive cocci on the same day. Empirical intravenous antibiotic therapy was initiated and later deescalated to oral tedizolid after methicillin-resistant Staphylococcus aureus was confirmed. Fever resolved by day 5, and follow-up CT scans showed improvement with continued antibiotic therapy.

SPE should be considered in patients with breast cancer who develop fever and new pulmonary nodules during adjuvant chemotherapy, particularly in those with underlying skin conditions or chemotherapy-induced immunosuppression. Prompt recognition and targeted antibiotic therapy are essential for achieving favorable clinical outcomes.