Histological examination, whether in vivo with endomyocardial biopsy (EMB) or of myocardium at autopsy, is key to the diagnosis of myocarditis, as it is for the diagnosis of inflammatory processes in other organs and tissues. [1,2]

Clinical requirements go beyond the essential information on presence or absence of myocardial inflammation: other crucial data include histological characteristics of the inflammatory process (active/quiescent or chronic inflammation, specific inflammatory cell types present, the extent and degree of severity, presence and grade of myocyte injury, presence of fibrosis) and particularly myocarditis histopathological subtypes and their possible related etiology/etiologies. In the context of EMB, all these data affect the course and prognosis of the disease and may guide therapy [3]; at autopsy they are helpful to understand whether myocardial inflammation is the cause of death, a contributory factor or an incidental finding [4].

For these reasons, although underused even in recommended clinical settings, and despite suffering from recognized relatively low sensitivity, EMB is still a fundamental tool to define the inflammatory process and is still considered the gold standard/reference standard for the diagnosis of myocarditis [5].

Over the years, a gap has developed between clinical needs and EMB histological information: this gap also involves terminology and definitional differences between clinical (fulminant, acute, subacute, chronic) and pathological (active, persistent, healing, chronic, borderline, healed) diagnostic categories - a relationship that needs to be clarified.

But the most important thing has been the progressive distancing of pathologists from the existing standardized criteria, resulting in lack of uniformity in pathologic diagnostic criteria: the very situation that moved the eight expert pathologists to formulate the Dallas Criteria (DC) in 1987 [6].

In this context, professional cardiovascular organizations or societies were probably not ready to face up to the new criticism and requirements.

The lack of uniformity in diagnostic criteria became painfully obvious during the COVID-19 pandemic, when significant differences in myocarditis reporting at post-mortem examination became clear, as did substantial discrepancies between rates of histopathologic myocarditis and myocarditis determined by cardiac magnetic resonance imaging [7,8].

To this scenario we can add the papers by De Gaspari et al. [9] and Lu et al. [10] on the diagnosis of myocarditis, which are part of a broader initiative by the two main societies of cardiovascular pathology, the Association for European Cardiovascular Pathology (AECVP) and the Society for Cardiovascular Pathology (SCVP). Starting from the state of the art on routine work up and reporting of myocarditis in various centers and from the reproducibility study on current myocarditis diagnostic criteria by a group of experts, the Societies would like to consider the possibility of future improvements in myocarditis guidelines and/or diagnostic criteria.

The authors of these two papers should be complimented for their clear analyses of the problems faced by pathologists and even experts when diagnosing myocarditis. Over the years, the medical community has changed its pathological and clinical approach to myocarditis. As a result, areas of controversy and uncertainties have accumulated.