Retroperitoneal Myoepithelial Carcinoma: A Case Report and Literature Review

Tong Wei,1,* Hongmin Quan,2,* Rengui Wang,3 Xiaoli Sun3 1Department of CT, People’s Hospital of Qingxian, Cangzhou, Hebei Province, People’s Republic of China; 2Department of Anesthesiology, People’s Hospital of Qingxian, Cangzhou, Hebei Province, People’s Republic of China; 3Department of Medical Imaging, Beijing Shijitan Hospital, Capital Medical University, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaoli Sun, Department of Medical Imaging, Beijing Shijitan Hospital, Capital Medical University, Yangfangdian Tieyi Road No. 10, Haidian District, Beijing, 100038, People’s Republic of China, Email [email protected]: Myoepithelial carcinoma is rare, and myoepithelial carcinoma occurring outside the head and neck is even rarer. We reported one case of retroperitoneal myoepithelial carcinoma.Case Summary: A 63-year-old woman who underwent computed tomography (CT) for progressive abdominal distension revealed a left retroperitoneal mass and subsequently underwent surgical treatment where the mass was completely removed with a postoperative diagnosis of retroperitoneal myoepithelial carcinoma. A follow-up CT review 40 days after surgery revealed a recurrence of the mass. After 8 months of chemotherapy and targeted immunotherapy, a follow-up review of the CT images revealed a gradual reduction in the mass. Four months after the cessation of chemotherapy and targeted drug combined immunotherapy, a follow-up review via CT revealed another recurrence and enlargement of the mass.Conclusion: CT of retroperitoneal myoepithelial carcinoma revealed a massive cystic solid mass in the abdominal cavity and retroperitoneum. The solid region of the mass was significantly enhanced and the cystic region was without enhancement on enhanced CT; the mass involved the adjacent duodenum, partial jejunum, and left renal vein. PET‒CT imaging revealed hypermetabolism in the solid region of the mass and no hypermetabolism in the cystic region.Plain Language Summary: We studied a rare cancer called retroperitoneal myoepithelial carcinoma to understand how to treat it better.Why: This cancer is tricky and often comes back after treatment. We wanted to find ways to help patients live longer.What we did: We followed one patient’s journey. Doctors used CT scans to see where the tumor was and how big it was. PET‒CT scans showed how active the cancer cells were. The patient had surgery to remove the tumor, but it came back. They then tried chemotherapy, targeted drugs, and immunotherapy. Sadly, the cancer returned again.What we found: This cancer is prone to coming back, but using multiple treatments together helps patients live longer. The scans were crucial for tracking the tumor and seeing how it changed.What it means: Treating this cancer is challenging, but combining different treatments works better than using just one. Our findings show that doctors need to keep a close watch on patients and use all available tools to fight this disease. This case helps us understand how to improve care for others with this rare cancer.Keywords: computed tomography, CT, myoepithelial carcinoma, retroperitoneal, rare diseases