Solaru Samantha A, Liu Marisa C, Lee Vincent, Bristow Robert E
Department of Obstetrics and Gynecology, University of California, Irvine-Medical Center, 3800 West Chapman Avenue, Suite 3400, Orange, CA 92868, USA.
Department of Gynecologic Oncology, University of California, Irvine-Medical Center, 3800 West Chapman Avenue, Suite 3400, Orange, CA 92868, USA.
Gynecol Oncol Rep. 2025 May 23;59:101769. doi: 10.1016/j.gore.2025.101769. eCollection 2025 Jun.
Low-grade serous carcinoma (LGSC) is a rare, indolent subtype of epithelial ovarian cancer that often arises from precursor lesions in the ovary or peritoneum and is associated with MAPK pathway mutations. Unlike high-grade serous carcinoma (HGSC), which typically originates from cells in the fallopian tube, LGSC shows limited response to chemotherapy. An isolated presentation in an extraperitoneal site, such as an inguinal lymph node, is exceedingly rare. We present a case of primary nodal LGSC arising in the setting of endosalpingiosis.
An 80-year-old woman presented with a two-year history of left lower quadrant pain and a newly enlarging left groin mass. Imaging identified a vascular left inguinal mass, and initial biopsy favored HGSC. Staging procedures including hysteroscopy, dilation and curettage, and diagnostic laparoscopy with bilateral salpingo-oophorectomy showed normal pelvic organs with no evidence of malignancy. Chemotherapy was initiated but resulted in only a modest response. Surgical resection of the mass itself revealed LGSC with adjacent endosalpingiosis. With no evidence of primary disease elsewhere, a diagnosis of primary inguinal node LGSC arising from endosalpingiosis was made.
This case highlights the diagnostic challenges of isolated LGSC without a detectable primary site. Initial misclassification can lead to suboptimal management. Accurate diagnosis requires thorough surgical and pathological evaluation to ensure appropriate treatment in these rare and atypical presentations.
低级别浆液性癌（LGSC）是上皮性卵巢癌中一种罕见的惰性亚型，通常起源于卵巢或腹膜的前驱病变，且与丝裂原活化蛋白激酶（MAPK）通路突变相关。与通常起源于输卵管细胞的高级别浆液性癌（HGSC）不同，LGSC对化疗的反应有限。在腹膜外部位（如腹股沟淋巴结）出现孤立性表现极为罕见。我们报告一例在输卵管内膜异位症背景下发生的原发性淋巴结LGSC病例。
一名80岁女性，有两年左下腹疼痛病史，左侧腹股沟肿物新近增大。影像学检查发现左侧腹股沟有一血管性肿物，初次活检倾向于HGSC。包括宫腔镜检查、刮宫术以及双侧输卵管卵巢切除术的诊断性腹腔镜检查等分期手术显示盆腔器官正常，无恶性肿瘤证据。开始化疗，但仅产生适度反应。肿物本身的手术切除显示为LGSC伴相邻输卵管内膜异位症。由于其他部位未发现原发性疾病证据，诊断为起源于输卵管内膜异位症的原发性腹股沟淋巴结LGSC。
本病例突出了无可检测到的原发部位的孤立性LGSC的诊断挑战。最初的错误分类可能导致治疗不当。准确诊断需要全面的手术和病理评估，以确保对这些罕见且不典型表现进行适当治疗。
