HPV Related Retroperitoneal Squamous Cell Cancer: A Rare Presentation

Objective: To describe the primary carcinoma of the retroperitoneum that was positive for human papillomavirus (HPV), a surrogate molecular marker for high-risk HPV (p16) and p53. Methods: This is a case report. Results: We report a case of 50year-old woman with a large retroperitoneal mass (squamous cell carcinoma on histology) that was treated in September of 2014 with radical concurrent chemotherapy with weekly cisplatin and pelvic radiation (4500 cGY) and additional right pelvic boost of 900 cGY. It was assumed she had FIGO stage IIIB local advanced cervical cancer. She initially presented with the right leg swelling, severe pain and difficulty in walking and was treated with antibiotics for presumed cellulitis. Several months later right leg extensive deep vein thrombosis (DVT) was diagnosed and was started on anticoagulation. CT scan and MRI reported a large right-sided retroperitoneal mass occluding the illiac vessels and ureter. The mass had invaded into the adjacent pelvic sidewall, with destruction of the iliacus muscle and underlying iliac wing. MRI showed that the cervix and uterus were both normal. On examination cervix appeared grossly normal and cervical punch biopsy revealed HSIL only. CT-guided biopsy of the mass revealed a moderately differentiated squamous cell carcinoma positive for p16 and p53. Conclusion: Primary squamous cell carcinoma of the retroperitoneum is a real entity that is unknown. It is unclear if primary neoplasia in the cervix was small from which a cell clone arose and migrated to the retroperitoneal space.