Lu Y, Zhu Q, Xiao Y, Pan RY, Deng LH, Zhang Q, Wang Y. Abdominal nodal metastasis from an unknown primary: A case report and review of literature. World J Clin Oncol 2026; 17(5): 120273 [DOI: 10.5306/wjco.v17.i5.120273]
Corresponding Author of This Article
Yue Wang, MD, Chief Physician, Deputy Director, Department of Oncology, Wujin Hospital Affiliated with Jiangsu University, No. 2 Yongning North Road, Tianning District, Changzhou 213000, Jiangsu Province, China. wangyue0512@163.com
Research Domain of This Article
Oncology
Article-Type of This Article
Case Report
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Lu Y, Zhu Q, Xiao Y, Pan RY, Deng LH, Zhang Q, Wang Y. Abdominal nodal metastasis from an unknown primary: A case report and review of literature. World J Clin Oncol 2026; 17(5): 120273 [DOI: 10.5306/wjco.v17.i5.120273]
World J Clin Oncol. May 24, 2026; 17(5): 120273 Published online May 24, 2026. doi: 10.5306/wjco.v17.i5.120273
Abdominal nodal metastasis from an unknown primary: A case report and review of literature
Yi Lu, Qi Zhu, Yao Xiao, Ru-Yan Pan, Ling-Hui Deng, Qi Zhang, Yue Wang
Yi Lu, Qi Zhu, Yao Xiao, Ru-Yan Pan, Ling-Hui Deng, Qi Zhang, Yue Wang, Department of Oncology, Wujin Hospital Affiliated with Jiangsu University, Changzhou 213000, Jiangsu Province, China
Yi Lu, Qi Zhu, Yao Xiao, Ru-Yan Pan, Ling-Hui Deng, Qi Zhang, Yue Wang, Department of Oncology, The Wujin Clinical College of Xuzhou Medical University, Changzhou 213000, Jiangsu Province, China
Co-first authors: Yi Lu and Qi Zhu.
Author contributions: Lu Y and Zhu Q reviewed the patient information and wrote the manuscript; Xiao Y and Pan RY collected the images and added annotations; Deng LH and Zhang Q checked the pathological analysis; Wang Y reviewed the manuscript and formulated the treatment plan; Lu Y and Zhu Q contributed equally to this work; and all authors agree to the publication of the final manuscript.
Supported by the Key Laboratory Open Project of Jiangsu Province Universities, No. XZSYSKF2020005; the 2024 Annual Basic Project of Nanjing Medical University Changzhou Medical Center, No. CMCB202427; and Changzhou Wujin District Science and Technology Support Program Project, No. WS201924.
Informed consent statement: Written informed consent was obtained from the patient for publication of this report and any accompanying images.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Corresponding author: Yue Wang, MD, Chief Physician, Deputy Director, Department of Oncology, Wujin Hospital Affiliated with Jiangsu University, No. 2 Yongning North Road, Tianning District, Changzhou 213000, Jiangsu Province, China. wangyue0512@163.com
Received: February 24, 2026 Revised: March 13, 2026 Accepted: March 27, 2026 Published online: May 24, 2026 Processing time: 87 Days and 23.1 Hours
Abstract
BACKGROUND
Cancer of unknown primary (CUP) represents 1%-3% of malignant tumors with prominent biological heterogeneity. Abdominal lymph nodes are common metastatic sites for various tumors. However, the lack of a comprehensive comparison of potential tissue origins in routine practice leads to diagnostic biases, particularly when CUP is associated with abdominal lymph node metastasis. We aimed to enhance the clinicians’ awareness in differentiating and diagnosing complex metastatic tumors, and optimize the treatment strategy to reduce the risk of misdiagnosis.
CASE SUMMARY
A 77-year-old man was admitted with a 1-month history of a gastric body ulcer. A gastroscopy biopsy revealed high-grade intraepithelial neoplasia, and an abdominal computed tomography scan showed multiple enlarged lymph nodes. He underwent laparoscopic subtotal gastrectomy, which confirmed early gastric cancer with neuroendocrine differentiation. However, abdominal lymph node immunohistochemistry (IHC) results were inconsistent. Multidisciplinary consultation indicated that the enlarged lymph nodes were distributed in the retroperitoneum and the vicinity of the iliac vessels, indicating pelvic tumor lymphatic drainage. Supplementary tests showed a total prostate-specific antigen (PSA) level > 100 ng/mL, and lymph node tissue was positive for prostate cancer-specific immunohistochemical markers PSA and α-methylacyl-CoA racemase. A bone scan confirmed multiple bone metastases, leading to a diagnosis of gastric carcinoma in situ and advanced prostate cancer. The patient received endocrine therapy for prostate cancer and bone protection treatment, with no obvious adverse symptoms reported.
CONCLUSION
In CUP with abdominal lymphatic metastasis, understanding anatomy, pathology, drainage, markers, and IHC aids early management and accurate diagnosis.
Core Tip: Cancer of unknown primary (CUP) is a metastatic cancer whose origin site remains undetermined after comprehensive examinations. Abdominal lymph node metastasis, a common clinical manifestation of CUP, is prone to diagnostic errors because the tissue of origin is often incompletely identified. We report a case where the initial diagnosis was early gastric cancer with abdominal lymph node metastasis. After relevant re-examination, the metastatic lymph nodes were determined to originate from prostate cancer. This emphasizes the importance of diagnostic awareness of suspicious metastatic lesions and the significance of multidisciplinary diagnosis and treatment.
