mucocele classification
- douglasrodrigomatt
- Apr 6
- 4 min read
Note: This content was automatically translated from Portuguese to English by Wix. Please disregard any grammatical or translation errors.
Hello everyone! The much-loved, feared and respected biliary mucocele has become an increasingly common diagnostic finding in our routine and, with the increase in specialties, the need for greater details in the description and identification of findings has increased proportionally.
In this post we will discuss the findings that help classify gallbladder mucocele, since this classification has been routinely requested mainly by gastroenterologists and endocrinologists. So, let's go!
but what is biliary mucocele?
First, let's make it clear that the definitive diagnosis is histopathology after surgical removal of the gallbladder, okay? Despite this, the extensive literature available on mucocele makes it clear that ultrasound findings are highly indicative of the diagnosis of biliary mucocele. So yes, in the case of mucocele, we can make the diagnostic impression of gallbladder mucocele, since we are performing an ultrasound examination and, in this case, the ultrasound diagnosis is this.
A mucocele is nothing more than an abnormal accumulation of thick mucus inside the gallbladder. This thick mucus causes a progressive increase in the content and consequently volume of the gallbladder, since its density does not allow it to be drained through the cystic duct into the extrahepatic bile ducts.
In this post we have a diagram of the evolution of cholecystitis to mucocele, take a look"
Some conditions favor the development of biliary mucocele, among the main ones are biliary stasis and comorbidities, such as endocrinopathies. In addition, they are much more common in dogs than in cats, so much so that all the content of this post is aimed at dogs, not cats, okay?
ultrasound findings
The characteristics of mucoceles depend on the degree to which we observe this pathology. Findings include echogenic bile, with content independent of gravity, thickening of the wall with anechoic projections towards the interior, which, due to the shape of the gallbladder, adopt a concentric pattern of these projections, adopting the well-known 'kiwi-like' shape. These projections may also include echogenic streaks.
As the projections of the wall become thicker and thicker, there may be a reduction in the luminal content until all the content we see is mucus coming from the wall. Crazy, right?
You can learn more about what is normal regarding the gallbladder by reading this post
A complete scan of the gallbladder, in both imaging planes (transverse and longitudinal), is necessary for the appropriate grading of the degree of mucocele.
severity of each case
First, we must remember that mucocele can range from "asymptomatic" to presenting serious clinical signs.
I put asymptomatic in quotation marks because it is difficult to say that the patient does not present any symptoms, since a symptom is what the patient feels (and he does not tell us), so I like to say that it can range from the 'absence of clinical signs' to severe symptoms.
More discreet and nonspecific signs such as sporadic vomiting, apathy and hyporexia can be observed, and in more severe cases we can observe significant abdominal pain, jaundice and increased abdominal volume.
Increasing severity of clinical signs with ultrasound signs such as steatitis and effusion adjacent to the gallbladder may be associated with gallbladder rupture, an acute abdominal emergency.
mucocele monitoring?
Yes, the literature is clear in saying that cholecystectomy is indicated for patients with biliary mucocele, however, for "asymptomatic" cases, there are lines of research that suggest monitoring.
The fear of cholecystectomy is due to the high mortality rate presented by the technique, however, we must remember that the majority of reported cases are due to patients in whom the surgical decision was made only in extreme cases, with signs of rupture or imminent rupture.
For cases where the surgical decision was made in less serious situations, things change, making cholecystectomy safer, even more so with the advancement of minimally invasive techniques and video-surgeries.
And perhaps, then monitoring can have its benefits, since decision-making can be done based on the evolution of the mucocele grades.
and how to graduate?
To begin with, we must remember that there are 6 degrees and that the classification parameters include the appearance of the luminal content and the wall.
gallbladder sediment can also be classified, click here to learn!
TYPE I
Hypoechoic thickening of the wall is observed, but here, the most important thing is the luminal, immobile echogenic content (not dependent on gravity).
TYPE II
The star-shaped appearance formed by the anechoic projections of the wall is observed incompletely, that is, only part of the wall presents this appearance. The luminal sediment is still observed in the center of the gallbladder.
TYPE III Now the anechoic projections of the wall promote a typical starry pattern, throughout the wall but still with luminal content (sediment).
TYPE IV
Here, the anechoic projections of the wall begin to show hyperechoic streaks, and the proportion of luminal content compared to the wall decreases.
TYPE V
The gallbladder becomes almost entirely "walled". The anechoic projections occupy almost the entire volume of the gallbladder, with some residual luminal content still present.
TYPE VI Now, the anechoic projections occupy the entire volume of the gallbladder, with no more luminal content (not even residual) being observed.
It is important to emphasize that hyperechoic streaks on the wall are not a good sign, and may be associated with areas of necrosis, with an imminent risk of gallbladder rupture.
music and description
This week on Instagram, I posted a case of biliary mucocele (checked it out) in the music and description, which is the same as the images below, so take a look at the image and answer the quiz.
What is the type of mucocele in the video above?
Type I
Type II
Type III
Type IV
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