Metastatic squamous cell carcinoma of unknown primary: a case report and brief literature review.

ABSTRACT: Carcinoma of unknown primary (CUP) is a rare malignancy characterized by metastatic disease without an identifiable primary tumor, even after extensive diagnostic evaluation. This case report described a 70-year-old female patient with squamous cell CUP (SCCUP) who initially presented with elevated carbohydrate antigen 19-9 and a diaphragmatic mass. Despite comprehensive workup, including ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography and a 90-gene expression assay, the primary site remained unclear. The patient underwent surgical resection followed by two cycles of systematic therapy and achieved a disease-free survival of 14 months. This case underscores the limitations of the current diagnostic tools and the potential role of multimodal therapy in the

SUBMITTER: Yang Y 

PROVIDER: S-EPMC12591943 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature