在乳癌患者全身正子造影中發現疑似mRNA疫苗引起淋巴結及脾臟影像異常──個案報告

Positron Emission Tomography/Computed Tomography Imaging Detection of mRNA Vaccination- Induced Abnormalities in Lymph Nodes and Spleen of Breast Cancer Patients: A case Report

腋窩淋巴結轉移是早期乳癌病人最重要的預後因子，因為淋巴結轉移範圍將影響治療方式的選擇。肌肉注射COVID-19mRNA疫苗，可能會誘發同側腋窩淋巴結反應。臨床上可能被錯誤認為是癌症轉移造成，或被歸類於因疫苗接種後的反應，而導致延誤治療。一名37歲女性為初診斷右側乳癌患者，在接受全身正子檢查前4天，於左上臂接種第二劑COVID-19mRNA疫苗（Moderna）。全身正子檢查發現右側乳房腫瘤及右側腋窩淋巴結；同時在左側鎖骨上窩、左側腋窩淋巴結及脾臟也有高度FDG攝取。研究顯示FDG全身正子檢查對腫大的淋巴結反應非常敏感，且肌肉注射COVID-19mRNA疫苗後常見同側腋窩淋巴結反應。此案例左側觀察到的鎖骨上窩、腋窩淋巴結FDG攝取增加，需考量可能是由於對疫苗的炎症免疫反應造成。

Axillary lymph node metastasis is the most important prognostic factor for patients with early-stage breast cancer, as the extent of lymph node metastasis affects the choice of treatment. Intramuscular injection of COVID-19 mRNA vaccine might induce ipsilateral axillary lymph node reactivity. This might be clinically misinterpreted as being a result of metastasis or classified as a post-vaccination reaction, leading to treatment delay. A 37-year-old woman with newly diagnosed right-sided breast cancer received a second dose of COVID-19 mRNA vaccine (Moderna) in her upper left arm 4 days before undergoing positron emission tomography/computed tomography (PET/CT) scan. The scan revealed the right-sided breast tumor and right axillary lymph node. Furthermore, high fluorodeoxyglucose (FDG) uptake was also evident in the left supraclavicular fossa, left axillary lymph node, and spleen. The findings indicate that FDG PET/CT scan is sensitive to swollen lymph node reactions, and that ipsilateral axillary lymph node reactions are common after intramuscular injection of COVID-19 mRNA vaccine. The increased FDG uptake observed in the supraclavicular fossa and left axillary lymph nodes in this patient might be the result of an inflammatory immune response to the vaccine.