When the Mirror-Body Meets the Microscope: A Liver-like Spleen in Situs Inversus Totalis

In the rarefied world of clinical imaging, some of the most striking lessons come from single patients whose anatomy defies the textbook. A case report published in the Journal of General Internal Medicine by Yosuke Miyaki, Shinichiro Okamoto, and Takahiro Kamiya of Kawasaki Municipal Kawasaki Hospital in Japan presents exactly such a lesson. Under the deceptively simple title A Liver-like Spleen in Situs Inversus Totalis, the authors document a patient with the complete mirror-image condition known as situs inversus totalis, in whom an enlarged spleen took on an appearance so reminiscent of liver tissue that it posed a genuine diagnostic challenge. The report, classified as a clinical image contribution, appeared online on 1 October 2026 and carries the digital object identifier 10.1007/s11606-026-10873-x.

Situs inversus totalis is a congenital condition in which the major visceral organs are reversed from their normal positions along the left-right axis. The liver comes to lie predominantly on the left, the stomach and spleen shift to the right, and the cardiac apex points rightward, a configuration called dextrocardia. Estimates of its prevalence vary, but the condition is generally thought to affect roughly one in ten thousand individuals, and many carriers live their entire lives unaware of their mirrored anatomy. The condition arises during embryogenesis, when the normally stereotyped left-right patterning of the developing embryo is globally reversed. A landmark study by Nonaka and colleagues, published in Nature in 2002 and cited in the report’s reference list, demonstrated in the mouse embryo that the directional flow of fluid across the node, the embryonic organizer structure, is sufficient to determine left-right patterning, and that artificially reversing this flow reverses organ situs. Motile cilia at the node generate this leftward current, and defects in ciliary function underlie many cases of laterality disorders, including both situs inversus and the more chaotic arrangement known as heterotaxy.

As Sutherland and Ware summarized in their 2009 review of disorders of left-right asymmetry, the clinical significance of situs anomalies lies less in the mirroring itself than in its associations. Pure situs inversus totalis, in which the reversal is complete and orderly, is frequently an incidental finding discovered on imaging performed for unrelated complaints. Heterotaxy, by contrast, involves ambiguous or discordant organ positioning and is strongly associated with congenital heart disease and other malformations. A hospital-based study by Chen and colleagues published in Birth Defects Research in 2020 examined comorbidities in patients with situs inversus totalis and documented the range of conditions that accompany the mirrored anatomy in hospital populations. Clinicians must also contend with the practical consequences of reversed anatomy: physical examination findings are transposed, electrocardiograms require lead reversal for correct interpretation, appendicitis presents with left-sided pain, and surgical approaches must be rethought from first principles.

Into this already unfamiliar anatomical landscape, the Japanese team’s patient added a second layer of complexity. The case involves a patient found to have massive splenomegaly, an abnormal enlargement of the spleen, in the setting of malignant lymphoma, a cancer of the lymphatic system. The keywords attached to the published article situs inversus, malignant lymphoma, and splenomegaly capture the three threads of the story. In a body with normal organ arrangement, an enlarged spleen occupies the left upper quadrant of the abdomen and can be identified by its characteristic shape, its relationship to the ribs and stomach, and its homogeneous tissue density on computed tomography or ultrasound. In a patient with situs inversus totalis, the spleen resides on the right, and when it grows to enormous size it can extend across the midline, displace neighboring structures, and present an imaging appearance that mimics other organs.

The central image that gives the report its title shows a spleen so enlarged and so altered in texture that it resembled liver parenchyma. The phrase liver-like spleen refers to this visual deception: on cross-sectional imaging, the organ’s density and architecture appeared more like hepatic tissue than like the typical spleen. For clinicians evaluating a patient with reversed anatomy and a large right-sided or midline abdominal mass, distinguishing an enormously enlarged spleen from a displaced or accessory liver lobe, a tumor, or an abnormal collection of fluid is not a trivial exercise. The authors’ acknowledgment section thanks Dr. Ken Sadahira and Dr. Mikio Okayama for their assistance in patient care, indicating that the case was managed by a clinical team rather than observed from afar. The report also notes that no datasets were generated or analyzed, consistent with its format as a clinical image publication rather than a research study.

The association between lymphoma and the spleen is well established. The spleen is a lymphoid organ, and lymphomas, which arise from lymphocytes, frequently involve it. Splenomegaly in lymphoma may reflect direct infiltration by malignant cells, congestion, or reactive changes, and an enlarged spleen can itself be the presenting sign that brings a patient to medical attention. Trautner and colleagues, in a 2010 report in Clinical Nuclear Medicine cited by the Japanese authors, described the additional value of hybrid imaging in a patient with newly diagnosed lymphoma who also happened to have situs inversus totalis, underscoring that this combination of mirrored anatomy and hematologic malignancy, while rare, recurs often enough in the literature to merit attention. When the two coincide, the diagnostic radiologist must interpret every image against a reversed anatomical template, and subtle findings can be misassigned to the wrong organ.

Eitler, Bibok, and Telkes, writing in the International Journal of General Medicine in 2022, provided a clinical review of situs inversus totalis that frames the practical stakes. They emphasized that while most affected individuals are asymptomatic, the condition demands vigilance in diagnostic reasoning, surgical planning, and the interpretation of imaging studies. Their review, together with the earlier genetic and epidemiological work cited in the present case report, forms the scholarly backdrop against which the Kawasaki team’s images should be read. The report’s contribution is not a new therapy or a genetic discovery but a vivid demonstration of how far normal anatomical assumptions can mislead even experienced clinicians when the underlying blueprint is mirrored and then distorted by disease.

The publication process itself reflects the case’s timeline. According to the article’s record, the manuscript was received on 1 April 2026, accepted on 24 September 2026, and published on 1 October 2026 in the Journal of General Internal Medicine, the flagship journal of the Society of General Internal Medicine. All three authors are affiliated with Kawasaki Municipal Kawasaki Hospital in Kanagawa, Japan, with Okamoto based in the Department of Hematology and Miyaki and Kamiya in the Department of Internal Medicine, Kamiya holding appointments in both departments. Miyaki wrote the initial draft of the manuscript, and all authors had access to the data and helped revise the intellectual content. The authors declared no conflicts of interest and received no funding for the work. Correspondence for the article is directed to Takahiro Kamiya, whose ORCID identifier is listed in the publication record.

Why should a single clinical image merit attention beyond the ward? The answer lies in the pedagogical power of the exceptional case. Medical education proceeds in part through pattern recognition, and patterns are learned from typical presentations. But diagnostic error frequently occurs at the boundaries, where rare anatomy, rare disease, and rare combinations interact. A liver-like spleen in a patient with situs inversus totalis is precisely such a boundary case. It reminds radiologists that organ identification rests on more than position and density, that clinical history and correlative imaging are indispensable, and that the mirrored body can transform familiar signs into unfamiliar configurations. For internists and hematologists, it reinforces the point that splenomegaly in lymphoma can reach sizes and textures that confound standard heuristics.

The case also connects to one of the most elegant stories in developmental biology. The discovery that cilia-driven nodal flow sets the left-right axis, confirmed by the artificial flow experiments in mice, transformed laterality disorders from a descriptive curiosity into a mechanistically understood class of conditions. Every patient with situs inversus totalis carries in their anatomy the fossil record of that embryological decision, reversed at its origin. When disease such as lymphoma then remodels the reversed organs, clinicians are asked to read two overlapping stories at once: the congenital mirror and the acquired pathology. The image published by Miyaki, Okamoto, and Kamiya captures that intersection in a single frame, a spleen grown so large and altered that it borrowed the appearance of its mirrored neighbor, the liver. For the general reader, it is a striking reminder that human anatomy, even at its most orderly, holds surprises, and that medicine’s textbooks are at best maps of the average, to be consulted with humility whenever an individual patient departs from it.

Subject of Research: Splenomegaly resembling liver tissue in a patient with situs inversus totalis and malignant lymphoma

Article Title: A Liver-like Spleen in Situs Inversus Totalis

Article References: Miyaki, Y., Okamoto, S., & Kamiya, T. (2026). A Liver-like Spleen in Situs Inversus Totalis. Journal of General Internal Medicine. https://doi.org/10.1007/s11606-026-10873-x

Image Credits: AI Generated

DOI: 10.1007/s11606-026-10873-x

Keywords: situs inversus, splenomegaly, malignant lymphoma, clinical imaging, left-right asymmetry, dextrocardia, heterotaxy, nodal cilia, hematology, diagnostic radiology, congenital anatomy, case report