目的： 探讨妊娠期局限性子宫内膜增生（localized endometrial proliferations of pregnancy， LEPP）的临床病理学特征变。方法： 收集上海交通大学医学院附属国际和平妇幼保健院2014年至2024年间收治的4例LEPP患者的临床病理学资料，复习其HE染色的病理组织切片，并进行免疫组化检测，并结合文献复习，总结其临床病理特点。结果： 4例患者的平均年龄为34.5岁（29~40岁），均在孕早期人流样本中发现LEPP。低倍镜下均见腺体扩张，腺体呈筛状或乳头状排列，上皮增生，细胞复层；高倍镜下细胞核轻度异型，核分裂象少见（0~1个/2 mm²）；其中1例背景可见钙化。免疫组化色示，4例患者均为雌激素受体（estrogen receptor，ER）、孕激素受体（progesterone receptor，PR）、配对盒基因2（paired box gene，PAX2）阳性，强于周围内膜；肿瘤蛋白53（protein 53，P53）野生型表达；错配修复蛋白阳性；同源性磷酸酶-张力蛋白（phosphatase and tensin homolog，PTEN）缺失。复习文献发现，LEPP具有腺上皮高度增生，细胞异型性小，生物学行为良性等特点。已报道的7例诊断为子宫内膜不典型增生或早期子宫内膜癌的病例，形态学描述更符合LEPP，随访均未见子宫内膜相关疾病复发。结论： LEPP是一类于妊娠期发生的病变，具有腺体内腺上皮高度增生、细胞异型性小、PTEN缺失、PAX2阳性等特点，目前认为其生物学行为良性。

Objective To investigate the clinicopathological features of localized endometrial proliferations of pregnancy (LEPP). Methods Clinicopathological data of 4 LEPP patients treated at the International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University School of Medicine from 2014 to 2024 were collected. Their hematoxylin and eosin (HE)-stained pathological sections were reviewed, immunohistochemical (IHC) testing was performed, and literature was reviewed to summarize clinicopathological characteristics. Results The average age of the 4 patients was 34.5 years (range: 29-40). LEPP was identified in first-trimester abortion specimens in all cases. Microscopically, low-power examination revealed dilated glands arranged in cribriform or papillary patterns, with epithelial hyperplasia and cell stratification. High-power examination showed mild nuclear atypia, with rare mitotic figures (0-1/2 mm²). Calcification was observed in one case. IHC staining demonstrated that all 4 patients were positive for estrogen receptor (ER), progesterone receptor (PR), and paired box gene 2 (PAX2), with stronger expression than in surrounding endometrium. Tumor protein 53 (P53) showed wild-type expression. Mismatch repair proteins were positive. Phosphatase and tensin homolog (PTEN) expression was absent. Literature review indicated that LEPP was characterized by marked glandular epithelial hyperplasia, minimal cytological atypia, and benign biological behavior. Seven cases diagnosed as atypical endometrial hyperplasia or early endometrial carcinoma exhibited morphological features more consistent with LEPP, and no recurrence of endometrial-related diseases was observed during follow-up. Conclusion LEPP is a type of lesion occurring during pregnancy characterized by marked glandular epithelial hyperplasia, minimal cytological atypia, PTEN loss, and PAX2 positivity. It is currently considered biologically benign.