Summers Cameron, Almeida Zoyla, Baig Mirza
HCA Florida Westside/Northwest Pathology Program, United States of America.
HCA Florida Northwest Hospital, Department of Surgery, United States of America.
Int J Surg Case Rep. 2025 Aug;133:111639. doi: 10.1016/j.ijscr.2025.111639. Epub 2025 Jul 9.
Mesonephric-like carcinoma (MLC) is a newly described malignant tumor that represents 1 % of endometrial cancers. The etiology of this disease is currently unknown but immunohistochemical expression with GATA-3, PAX-8 and TTF-1 and lack of ER/PR positivity can aid in correct diagnosis.
A 73-year-old female presented to our hospital with post-menopausal bleeding, an initial hysteroscopy identified a lesion suggestive of endometrial cancer. Ultimately, the patient underwent a hysterectomy and a bilateral salpingectomy/oophorectomy. Chemotherapy ensued due to metastatic disease. At 7 months post-op, the patient appeared to be doing well. Grossly, the lesion was 5.5 cm and appeared to infiltrate the entire thickness of the myometrium. Microscopically, densely packed malignant glands were seen with eosinophilic secretions. GATA-3, PAX-8 and TTF-1 immunostains were all positive. ER and PR immunostains were negative. Finally, a wild-type staining pattern was seen with p-53. PIK3CA and KRAS mutations have been observed in other cases of MLC.
Currently no standardized treatment regimen exists for this cancer; chemotherapy utilization including carboplatin and paclitaxel treatments are seen in medical literature. Researchers have explored the expression of the L1CAM adhesion molecule and have found higher expression in MLC compared to endometrioid endometrial carcinoma (EEC).
Awareness of this entity is important due to its rarity, clinical course, and histological similarities to EEC. Ultimately, eosinophilic secretions on histology and the specific immunophenotype can help guide a diagnosis of MLC.
中肾样癌（MLC）是一种新描述的恶性肿瘤，占子宫内膜癌的1%。该疾病的病因目前尚不清楚，但GATA-3、PAX-8和TTF-1的免疫组化表达以及缺乏ER/PR阳性有助于正确诊断。
一名73岁女性因绝经后出血就诊于我院，初次宫腔镜检查发现一处提示子宫内膜癌的病变。最终，患者接受了子宫切除术及双侧输卵管切除术/卵巢切除术。因出现转移疾病，随后进行了化疗。术后7个月，患者情况似乎良好。大体上，病变大小为5.5厘米，似乎浸润了子宫肌层的全层。显微镜下可见密集排列的恶性腺体及嗜酸性分泌物。GATA-3、PAX-8和TTF-1免疫染色均为阳性。ER和PR免疫染色为阴性。最后，p-53显示野生型染色模式。在其他MLC病例中已观察到PIK3CA和KRAS突变。
目前针对这种癌症尚无标准化治疗方案；医学文献中可见使用包括卡铂和紫杉醇治疗在内的化疗方法。研究人员探讨了L1CAM黏附分子的表达，发现与子宫内膜样腺癌（EEC）相比，MLC中的表达更高。
鉴于其罕见性、临床病程以及与EEC的组织学相似性，认识这一实体很重要。最终，组织学上的嗜酸性分泌物及特定免疫表型有助于指导MLC的诊断。
