BACKGROUND Papillary breast lesions may be benign, atypical, and malignant lesions. Pathological and clinical differentiation of breast papillomas can be a challenge. Unlike malignant lesions, benign breast papillomas are not classically associated with lymph node and distant metastasis. We report a unique case of a recurrent, benign breast papilloma presenting as an aggressive malignant tumor. CASE PRESENTATION Our patient was a 56-year-old postmenopausal African American woman who was followed in the breast clinic with a long history of multiple breast papillomas. She underwent multiple resections over the course of 7-9 years. After being lost to follow-up for 2 years, she once again presented with a slowly enlarging left breast mass. Subsequent imaging revealed a predominantly cystic mass in the left breast, as well as a suspicious hypermetabolic internal mammary node and a hypermetabolic nodule in the pretracheal space. Biopsy of the internal mammary node demonstrated papillary neoplasm with benign morphology and immunostains positive for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2/Neu. Due to the clinical picture concerning for malignancy, the patient was then started on endocrine therapy with palbociclib and letrozole before surgery. She then underwent simple mastectomy and sentinel lymph node dissection with negative nodes and pathology once again revealing benign papillary neoplasm. She underwent adjuvant chest wall radiation for 6 weeks and received letrozole following completion of her radiation therapy. She was without evidence of disease 30 months after surgery. CONCLUSIONS We present an unusual case of multiple recurrent peripheral papillomas with entirely benign histologic features exhibiting malignant behavior over a protracted period of many years, with an invasion of pectoralis musculature and possibly internal mammary and mediastinal nodes. Her treatment course included multiple surgeries (ultimately mastectomy), radiation therapy, and endocrine therapy.

中文翻译：

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不寻常的复发性转移性良性乳头状瘤：病例报告。

背景技术乳腺乳头状病变可以是良性、非典型和恶性病变。乳腺乳头状瘤的病理和临床分化可能是一个挑战。与恶性病变不同，良性乳腺乳头状瘤通常与淋巴结和远处转移无关。我们报告了一个独特的病例，即复发性良性乳头状瘤表现为侵袭性恶性肿瘤。病例介绍 我们的患者是一位 5​​6 岁的绝经后非洲裔美国女性，她在乳腺诊所接受随访，患有多发性乳头状瘤的长期病史。她在 7 至 9 年间接受了多次切除术。两年后失访，她再次出现左乳肿块缓慢增大。随后的影像学检查显示，左乳中有一个主要为囊性的肿块，以及气管前间隙中可疑的代谢亢进的内乳淋巴结和代谢亢进的结节。内乳淋巴结活检显示乳头状肿瘤具有良性形态，雌激素受体、孕激素受体和人表皮生长因子受体 2/Neu 免疫染色呈阳性。由于临床表现涉及恶性肿瘤，患者在手术前开始接受哌柏西利和来曲唑的内分泌治疗。然后，她接受了简单的乳房切除术和前哨淋巴结清扫术，淋巴结阴性，病理再次显示良性乳头状肿瘤。她接受了 6 周的辅助胸壁放疗，并在放射治疗完成后接受了来曲唑治疗。手术后 30 个月，她没有任何疾病迹象。结论 我们提出了一个不寻常的多发性复发性外周乳头状瘤病例，其组织学特征完全良性，在长达多年的时间里表现出恶性行为，并侵犯胸大肌组织，并可能侵犯内乳和纵隔淋巴结。她的治疗过程包括多次手术（最终是乳房切除术）、放射治疗和内分泌治疗。