Deep within the pelvis, within the fat, there is a 10 cm sized mass.
The mass has an insinuating contour around surrounding structures, but itself appears well circumscribed with a thin capsule or pseudocapsule. It is mixed soft tissue and fat density, with extensive nodular enhancement internally within the soft tissue components.
- Posteriorly, the mass abuts the mesorectal fascia, without infiltration into the perirectal space.
- Right laterally, the mass abuts the right internal iliac vessels against the right lateral pelvic side wall.
- Inferiorly, the mass abuts the seminal vesicle, which is displaced inferiorly, without infiltration of the structure.
- Superiorly, a loop of distal ileum is draped over the anterior/superior margin of the mass (Key image).
- Posterior/inferiorly, the sigmoid colon is draped over the posterior left lateral margin of the mass, but is separated from the mass by a thin fat plane.
- Superior right laterally, the mass abuts the right external iliac vessels, and a second loop of small bowel abuts the superior right lateral wall of the mass.
The superior rectal branch of the SMA courses through (within) the posterior margin of the mass.
No lymphadenopathy, suspicious bony lesion, or regional metastases in the field of view.
In summary, there is a mixed fat and soft tissue density, intraperitoneal mass centred within the pelvis, which should be considered to be malignant. Most likely representing a liposarcoma and closely related to surrounding structures without evidence of infiltration.