A 52 year old female with complaints of abdominal pressure,…

A 52 year old female with complaints of abdominal pressure, increasing abdominal girth, ‘crampy’ abdominal pain and decreased ability to eat was referred for an abdominal ultrasound by her physician. Medical history includes mucinous cystadenocarcinoma of the appendix. U/S: A complex mucinous mass with hypoechoic internal echoes was identified in the abdomen compressing the intra-abdominal structures. Most probably the abnormality is: