Squamous cell carcinoma of unknown primary site presenting with an abdominal wall lesion as the primary symptom: A case report and review of the literature

Squamous cell carcinoma of unknown primary site (SC CUP) is a rare malignant tumor, and its histogenesis and appropriate treatment are unclear. To the best of our knowledge, this type of carcinoma with abdominal wall lesions as the primary presenting symptom 3 months after laparoscopic surgery, has not been previously described in the literature. In the present study, a postmenopausal 54-year-old female patient was diagnosed with pain from the right abdominal puncture site 3 months after laparoscopic unilateral left salpingo-oophorectomy at a local hospital, at which time the left ovary and Fallopian tube were free of malignant tumor. Computed tomography (CT) imaging showed a subcutaneous nodule with a size of 6.2×3.3 cm. A wide excision of the lesion with safety margins and repair of the abdominal wall was performed, and the histopathological results and various investigations lead to the diagnosis of metastatic well-differentiated SC CUP. The patient underwent three surgeries and eight cycles of Taxol and cisplatin/carboplatin chemotherapy, and received a total of 10.8 Gy palliative radiation. However, the patient succumbed to intestinal bleeding, thrombocytopenia and multiple organ failure with pelvic recurrence and liver metastases at 10 months post-diagnosis. The prognosis of SC CUP, particularly with multiple metastases, is extremely poor. Although chemotherapy, surgery and radiotherapy have a certain role in the treatment, no regimen has been established as a standard therapy and palliative care could be recommended.