Gastric-type endocervical adenocarcinoma with peritoneal dissemination after chemoradiotherapy: a case report and review of the literature

Background Gastric-type endocervical adenocarcinoma (GAS) is the most common HPV-independent cervical adenocarcinoma. It is characterized by diagnostic difficulty, resistance to chemoradiotherapy and a propensity for peritoneal spread. Case presentation A 68-year-old woman presented with chronic hypogastric pain and a large hydrometra. Cervical cytology and an initial biopsy were non-diagnostic. A repeat biopsy established GAS (CK7-positive; p16, CK20, CDX2, estrogen receptor and PAX8-negative; wild-type p53; negative high-risk HPV by PCR), FIGO 2018 stage IIB, with negative staging imaging. After concurrent cisplatin-based chemoradiotherapy and brachytherapy, MRI showed only a 23% reduction of the tumor. Radical hysterectomy, delayed by six months, revealed residual tumor with omental and pelvic peritoneal metastases that had not been detected on staging imaging. She received five cycles of carboplatin–paclitaxel as first-line systemic therapy, complicated by grade 3 radiation proctitis, right ureteral and vesicovaginal fistulas, and severe hematologic toxicity. Eight months after completing chemotherapy, she developed malignant bowel obstruction from peritoneal progression. PD-L1 was negative (combined positive score 0). She died under palliative care 25 months after diagnosis. Conclusions This case illustrates the diagnostic pitfalls and radioresistance of GAS and its capacity for peritoneal spread. Together with a focused review of published locally advanced cases, it suggests that staging laparoscopy and earlier comprehensive biomarker testing deserve prospective evaluation.