Abstract Background The present paper focuses on eponyms, that is, terms with proper names, in particular, derived from world mythologies, the Bible, and modern literature. The study highlights the significance of this terminological phenomenon in the English sublanguage of medicine and discusses its role in the process of writing medical case reports. The objectives of the research are to study the prevalence of eponyms in the English language in medical case reports and to analyze the etymology of the revealed terms. The deeper purpose of our study is to demonstrate that eponymic terms in general, and mythological and literary eponyms, in particular, are present in doctors’ spoken and written discourse far more extensively than might seem at first glance. By drawing attention to this terminological phenomenon, we will provide relevant guidelines, which will ensure the correct use of eponyms by medical professionals who will deal with the genre of medical case reports. Methods We studied the prevalence of these terms in the issues of Journal of Medical Case Reports (2008–2022) and classified them according to their etymological origin and frequency of use. The selected medical case reports were considered using the methods of quantitative examination, and structural, etymological, and contextual analyses. Results We detected the major tendencies in using mythological and literary eponyms in medical case reports. We found a total of 81 mythological and literary eponyms, represented by 3995 cases of use in Journal of Medical Case Reports issues, and traced the etymology of their onomastic components. Hence, we delineated the five most prevalent sources of these terminological units: Greek mythology, Roman mythology, other world mythologies, the Bible, and fiction. The research revealed that modern medical case reports largely rely primarily on Greek mythology (65 eponyms, 3633 results), which is due to a rich informational and metaphorical arsenal of these ancient corpora of human knowledge. The group of eponyms rooted in Roman mythology ranks second, and these terms are much less prevalent in modern medical case reports (6 eponyms, 113 results). Four eponyms (88 results) represent other world mythologies (Germanic and Egyptian). Two terms with onomastic components come from the Bible (15 results), and four eponyms stem from modern literature (146 results). We also detected several widespread mistakes in the spelling of some mythological and literary eponyms. It is our opinion that the awareness of an eponym’s etymology can effectively prevent and minimize the appearance of such errors in medical case reports. Conclusions The adequate use of mythological and literary eponyms in medical case reports is an effective way to share one’s clinical findings with colleagues from all over the world, because these eponyms are internationally widespread and understood. Correct use of eponyms promotes the continuity of medical knowledge and ensures conciseness and brevity, which are indispensable features of medical case reports as a genre. Therefore, it is highly important to draw students’ attention to the most prevalent mythological and literary eponyms, used in contemporary medical case reports, so they could use them appropriately, as well as with due awareness of the origin of these terms. The study also demonstrated that medicine and humanities are closely related and inherently interconnected areas. We believe that the study of this group of eponyms should be an integral component of doctors’ training and continuing professional education. This will ensure the interdisciplinary and synergic approach in modern medical education, which in turn will promote the all-round development of future healthcare specialists, endowed not only with professional expertise, but also with extensive background knowledge.