Abstract
BACKGROUND: Appendiceal mucinous adenocarcinoma is an extremely rare disease in clinical practice. Here, we report a case of unprecedented size that occupied the entire abdomen of a man. CASE PRESENTATION: A 49-year-old Chinese Han man presented with symptoms of abdominal distension. During a computed tomography imaging examination, a cystic-solid mass that occupied his entire abdominal cavity was detected. During exploratory laparotomy, an appendiceal tumor in his abdominal-pelvic cavity measuring 27.6 × 14.2 cm was found, and he underwent tumor resection. The pathology of the tumor identified a well-differentiated appendiceal mucinous adenocarcinoma with mucin infiltrating into the soft tissue of the lump edge and omentum tissue. After surgery, our patient accepted intraperitoneal infusion chemotherapy. At present, he has had no recurrence for 15 months. CONCLUSIONS: To the best of our knowledge, the present case is the largest appendiceal mucinous adenocarcinoma reported. Surgical tumor resection is the preferred treatment for appendiceal mucinous adenocarcinoma. This is supplemented by chemotherapy which can further prolong survival.