AUTHOR=Dong Wanhui , Cheng Li , Xu Jing , Xu Sheng , Yin Yuling , Sun Qingming , Wu Yong , Leng Yuling TITLE=Overcoming diagnostic pitfalls in primary gastric squamous cell carcinoma: the imperative of adequate sampling in an elderly female patient, case report JOURNAL=Frontiers in Oncology VOLUME=Volume 15 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1695030 DOI=10.3389/fonc.2025.1695030 ISSN=2234-943X ABSTRACT=ObjectiveTo report the diagnosis and treatment of a rare case of primary gastric squamous cell carcinoma (PGSCC) in an elderly female, and to explore the diagnostic pitfalls and individualized treatment strategies.MethodsWe conducted a retrospective analysis of the clinical, imaging, endoscopic, and pathological data of a 77-year-old female patient. The evolution of the diagnosis from the initial “possible adenocarcinoma” to the final diagnosis of “ squamous cell carcinoma” was emphasized.ResultsThe patient presented with abdominal pain. The first endoscopic biopsy, due to the limited tissue sample, showed immunohistochemistry results of CKpan (+), CK7(+), MUC5AC (focal+), and Ki-67(partly+), favoring a diagnosis of adenocarcinoma. A subsequent deep biopsy with complete immunohistochemistry (CK5/6+, P40+, P63+) confirmed the diagnosis of gastric squamous cell carcinoma. Given the patient’s advanced age, poor physical condition, and refusal of surgery, a palliative treatment plan of “Raltitrexed + Sintilimab” was finally decided upon after a multidisciplinary consultation.ConclusionThis case highlights the importance of adequate sampling in the diagnosis of gastric squamous cell carcinoma to avoid misdiagnosis due to limited specimens. It also provides a potential treatment option of immune therapy combined with low-dose chemotherapy for elderly patients with gastric squamous cell carcinoma who are not suitable for surgery.