Brief Answer:
My opinion as follows:

Detailed Answer:
Hello doctor XXXX!

Welcome on HCM!

You are right about the uncertainty surrounding mediastinal cysts as they are a rare entity; with a variety of etiologies depending their embryological origin and different locations within the mediastinum.

As the discussion is about a cyst positioned between the pulmonary and heart boundaries, it is more probable to be a pleuropericardial cyst which in fact is a benign structure positioned most frequently in the anterior mediastinum.

Coming to this point, I would like to know more precisely the clinical symptomatology that have led to cyst discovery; although most of them are quite asymptomatic and are revealed by incidental chest imagine tests.

For me as a cardiologist is very important to define the exact nature of this mediastinal cyst: whether it is really a pleuro-pericardial cyst, characterized generally by an uneventful clinical course, which when presented in small dimensions and clinically silent, commonly does not require any treatment, but just a careful continuous follow up.

In such case, if the real nature is a pleuro-pericardial cyst there is not much to worry about.

But as mediastinum represents a variety of tissues, other potential etiologies are possible.

A bronchogenic cyst or other alternatives like a foregut, enterogenous, neuroenteric or mesothelial cyst may be possible.

If any of these latter alternatives is the cause, then the an underlying obvious clinical symptomatology is more likely.

From a cardiovascular perspective it is very important to define any possible relationships or connections with the blood vessels or adjacent structures.

In this regard, contrast enhancement angio CT or MRI would be beneficial.

Also, radionuclide scan imagines would be valuable.

The only complications of a real pleuropericardial cyst when large enough would be intermittent pain and eventually cyst inflammation/infection. That's why it is necessary a close monitoring of the situation.

I would like to review any available medical tests (ECG, cardiac ultrasound, chest CT or MRI, etc.); in such way I could give a more precise opinion on the possible implication of any cardiovascular issues.

Meanwhile, I would encourage also a pulmonologist evaluation and even follow up if the cyst is affecting any portion of the lung tissue (lung compression is sometimes revealed especially in bronchogenic cysts), or pulmonary infections represent the predominant clinical symptomatology.

Hope to have been of some help to you!

In case of any further questions , I would be glad to discuss with you!

Kind regards,

Dr. Iliri

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