Abstract：
Lymphoma is the fourth most common tumor to display placental metastasis. This study aimed to report a case of high-grade lymphoma involving the placenta and review the literature on lymphomas metastatic to the placenta. A systematic review was performed following the PRISMA guidelines, using the keywords \"lymphoma\" AND \"placenta.\" All case reports and case series on lymphoma infiltrating the placenta were collected. Eight cases from 7 studies, including the present case, were synthesized. The mean patient age is 29.5 years. The clinical presentation is non-specific. Hematologic derangements included cytopenias or cytoses, and elevated prothrombin time. The mean gestational age (GA) when a diagnosis of lymphoma was rendered is 27 weeks. Five cases presented with either lymphadenopathy or visceral masses on imaging. Four of these cases eventually led to maternal demise. The mean GA when the fetus was delivered is 31 3/4 weeks. Grossly, most placentas had non-specific findings. Leukemic infiltrates were mostly seen within intervillous spaces. Intravillous infiltrates were associated with high-grade lymphomas, resulting in either maternal demise or stillborn fetuses. This study suggests that the placenta has mechanisms to guard against malignancies; however, these defense mechanisms are not foolproof and may be breached by tumor cells.
摘要：
淋巴瘤是显示胎盘转移的第四最多见的肿瘤。本研究旨在报告一例涉及胎盘的高级别淋巴瘤，并回顾有关转移到胎盘的淋巴瘤的文献。根据PRISMA指南进行了系统审查，使用关键词\"淋巴瘤\"和\"胎盘。“收集了所有病例报告和胎盘浸润淋巴瘤的病例系列。7项研究中有8例，包括本案,是合成的。患者平均年龄为29.5岁。临床表现是非特异性的。血液学紊乱包括血细胞减少或细胞增多，凝血酶原时间升高.诊断为淋巴瘤时的平均胎龄（GA）为27周。5例影像学表现为淋巴结肿大或内脏肿块。其中4例最终导致产妇死亡。胎儿分娩时的平均GA为313/4周。严重的,大多数胎盘有非特异性发现.白血病浸润主要见于绒毛间空间内。静脉浸润与高级别淋巴瘤有关，导致产妇死亡或死产胎儿。这项研究表明，胎盘具有预防恶性肿瘤的机制；然而，这些防御机制并非万无一失，可能会被肿瘤细胞破坏。
