Ishii Mikako, Horimoto Yoshiya, Koyama Yoichi, Adachi Kayo, Ueda Ai, Kawate Takahiko, Kaise Hiroshi, Yamada Kimito, Sato Eiichi, Abe Shinji, Ishikawa Takashi
Department of Breast Surgical Oncology, Tokyo Medical University, Tokyo, Japan.
Department of Breast Oncology, Ibaraki Medical Center, Tokyo Medical University, Ami, Ibaraki, Japan.
Surg Case Rep. 2025;11(1). doi: 10.70352/scrj.cr.25-0050. Epub 2025 May 8.
Anti-MDA5 (melanoma differentiation-associated gene 5) antibody-positive dermatomyositis is a severe subtype of dermatomyositis associated with rapidly progressive interstitial lung disease, which carries an extremely high mortality rate. Prompt diagnosis and therapeutic intervention are crucial for survival. Here, we report a rare case of occult breast cancer in a patient with anti-MDA5 antibody-positive associated interstitial pneumonia. Following the control of the lung disease with immunosuppressive therapy, the patient successfully underwent neoadjuvant chemotherapy (NAC) and curative surgery.
A 63-year-old woman presented with progressive dyspnea. Imaging tests revealed diffuse ground-glass opacities in both lungs and enlarged left axillary lymph nodes. Blood tests showed elevated KL-6 levels and anti-MDA5 antibodies. Although no skin lesions or myositis were observed, she was diagnosed with anti-MDA5 antibody-positive associated interstitial pneumonia. Immunosuppressive therapy, including steroid pulse therapy, tacrolimus, cyclophosphamide pulse therapy, and plasma exchange, was initiated, leading to an improvement in her lung condition. She was then initially referred to the department of plastic surgery for further evaluation of the enlarged left axillary lymph node. Excisional biopsy of the enlarged left axillary lymph node revealed triple-negative occult breast cancer (cTXN1M0, Stage IIA). After the patient was referred to our department, NAC was initiated, achieving a clinical partial response while avoiding exacerbation of the interstitial pneumonia. After completing NAC, a left axillary lymph node dissection was performed, and the final pathological diagnosis was ypTXN2aM0 (Stage IIIA). Postoperative radiotherapy was omitted due to the risk of worsening the interstitial lung disease, and capecitabine was administered for 6 months. The patient has remained recurrence-free for 3 years following treatment.
This case highlights the successful management of triple-negative breast cancer under the constraints of anti-MDA5 antibody-positive associated interstitial pneumonia. To ensure the smooth implementation of breast cancer treatment while controlling interstitial pneumonia, close collaboration with respiratory physicians was essential for a successful outcome.
抗MDA5（黑色素瘤分化相关基因5）抗体阳性皮肌炎是皮肌炎的一种严重亚型，与快速进展的间质性肺病相关，死亡率极高。及时诊断和治疗干预对生存至关重要。在此，我们报告一例抗MDA5抗体阳性相关间质性肺炎患者合并隐匿性乳腺癌的罕见病例。在通过免疫抑制治疗控制肺部疾病后，患者成功接受了新辅助化疗（NAC）和根治性手术。
一名63岁女性出现进行性呼吸困难。影像学检查显示双肺弥漫性磨玻璃影和左腋窝淋巴结肿大。血液检查显示KL-6水平和抗MDA5抗体升高。尽管未观察到皮肤病变或肌炎，但她被诊断为抗MDA5抗体阳性相关间质性肺炎。开始进行免疫抑制治疗，包括类固醇冲击治疗、他克莫司、环磷酰胺冲击治疗和血浆置换，肺部状况得到改善。然后她最初被转诊至整形外科，以进一步评估左腋窝肿大淋巴结。左腋窝肿大淋巴结切除活检显示三阴性隐匿性乳腺癌（cTXN1M0，IIA期）。患者转诊至我科后，开始进行NAC，在避免间质性肺炎加重的同时取得了临床部分缓解。完成NAC后，进行了左腋窝淋巴结清扫，最终病理诊断为ypTXN2aM0（IIIA期）。由于存在间质性肺病恶化的风险，术后未进行放疗，给予卡培他滨治疗6个月。治疗后患者已无复发存活3年。
本病例突出了在抗MDA5抗体阳性相关间质性肺炎的限制下成功治疗三阴性乳腺癌的经验。为确保在控制间质性肺炎的同时顺利实施乳腺癌治疗，与呼吸内科医生密切合作对于取得成功结果至关重要。
