Primary Cardiac B-Non-Hodgkin Lymphoma Disguised as a Pacemaker Endocarditis
The very interesting case report by Fleissner et al[1] represents an example of a diagnostic mistake where a diagnosis of a common disease
was made, but a rare one was found. The authors are to be congratulated on their courage
to report this “negative” case, because learning does not always come from success,
but also from mistakes. If mistakes are not reported, learning from them is impossible.
Fortunately, in this case the patient received an adequate therapy and had a comparatively
good outcome.
Looking at the echocardiography video retrospectively, one easily recognizes that
it does not show the typical features of a lead endocarditis. As the authors comment,
a thoracic computed tomography scan would have been appropriate, but was not performed.
In this case, although the ultrasound picture does not show a clear pacemaker lead
vegetation, the clinical picture of the patient together with the higher incidence
of lead endocarditis compared with a cardiac tumor led the authors to pursue the diagnosis
of a lead infection. The recommendations for the management of pacemaker lead infections
from 2010,[2] and the Heart Rhythm Society Expert Consensus Statement on cardiovascular implantable
electronic device lead management and extraction from 2017,[3] unfortunately not cited in the case report, show a class I indication for lead removal
in cases of definitive lead endocarditis.
What is to be learned here? It seems that—although “common is common and rare is rare”
is a valid medical principle—sometimes the sound of hoof beats should lead to consider
the possibility of zebras, not only of horses.
