The ultrasound diagnosis of Pseudomyxoma Peritonei is part of the differential diagnosis of abdominal effusions.
Pseudomyxoma Peritonei is a situation in which the abdominal cavity is disseminated with mucin following the rupture of a mucinous neoplasm of the appendix or, more rarely, of the ovary or other abdominal organs. Its effective treatment is primarily based on an early clinical suspicion, which leads to the prompt execution of diagnostic investigations (CT scan and possible diagnostic laparoscopy) to have the correct diagnosis and detect the presence of aggressive characteristics (mucin cellularity, presence of atypia, etc. .).
The most frequent signs of suspicion are often nonspecific: progressive abdominal distension, nausea or vomiting, constipation, weight loss, the appearance of umbilical or inguinal hernia, abdominal pain leading to suspicion of acute appendicitis . Sometimes the diagnosis starts from the finding of an ovarian mass.
Very frequently, the first examination that is required is an abdominal ultrasound, which shows the presence of liquid effusion in the abdomen. Let's see the ultrasound features that can lead to suspect a Pseudomyxoma Peritonei.
ultrasound view of the female pelvis: the picture shows the presence of effusion with mixed ultrasound features. In the context of an anechoic fluid there are echogenic masses that aggregate in agglomerates with mixed density. If the patient is invited to swing on the pelvis, it is observed that these masses tend to move and return to position, as if they were glued together. This is the behavior of gelatine. On the other hand, a dense body that floats in a fluid tends to remain suspended and slowly redeposit.
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laparoscopic view of the female pelvis: the picture shows the laparoscopic aspect of the previous ultrasound image. It can be seen how mucin adheres to surfaces with viscous characteristics, which explain its inertia to movement. In this case there are no infiltrative aspects of the peritoneum. It is acellular mucin.
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ultrasound vision of a mucinous tumor with rupture of the appendix wall: the picture shows the appearance of the appendix. The walls are thickened, the lumen of the appendix is occupied by material with the same characteristics described above. The point where the rupture of the appendix wall occurred and from which the mucin emerges is evident.
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laparoscopic vision of a mucinous tumor of the appendix (LAMN): the picture shows the appearance of the appendix in the above case. The thickened area in the distal half is evident.
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mucinous tumor with rupture of the appendix wall: the area of rupture of the wall of the appendix is evident, from which mucin comes out.
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mucinous tumor of the appendix, macroscopic section (case above): the area of rupture of the wall of the appendix is evident, from which mucin comes out.
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In its overall view, the presence of an image of thickened loop of bowel (the appendix), with a breakage in its wall and dilated lumen from hypoechoic material with isoechogenic sedimentsthat it is also found free in the abdominal cavity, must lead to suspicion of a Pseudomyxoma Peritonei due to a perforated mucinous appendix tumor (LAMN). It is advisable to send Patients to a Center of Reference for the pathology, refraining from resective surgery.
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