Pelvic metastatic squamous cell carcinoma of unknown primary site: A case report and brief literature review

Rationale:Cancer with unknown primary site is a kind of disease that is difficult to deal with clinically, accounting for 2% to 9% of all newly diagnosed cancer cases. Here, we report such a case with pelvic metastatic squamous cell carcinoma of an unknown primary site and review the relevant literature.Patient concerns & Diagnoses:A 43-year-old Chinese female patient was referred to our hospital and initially diagnosed as "malignant tumor of right adnexal area?, obstruction of right ureter, secondary hydronephrosis".Interventions:Thereafter cytoreductive surgery was performed which included a total hysterectomy, left adnexectomy, partial omentum resection, pelvic lymph node dissection, and para-aortic lymph node dissection. The primary lesion could not be identified by supplementary examination and postoperative pathology. The patient was diagnosed as pelvic metastatic squamous cell carcinoma whose primary site was unknown. To prevent a recurrence, we administered adjuvant chemotherapy for the patient.Outcomes:The patient was followed up after treatment, complete remission has been maintained for 72 months, and no recurrence or metastasis has been found.Lessons:Our case demonstrates that surgery combined with chemotherapy could be helpful for pelvic metastatic squamous cell carcinoma of unknown primary site.