Schistosomal appendicitis: A serious and often misdiagnosed condition

Abstract

Schistosomal appendicitis (SA) is a rare but serious complication of schistosomiasis, a parasitic disease affecting over 250 million people worldwide. A recent retrospective study by Wang et al provides important insights into the clinicopathological characteristics of SA. The study compared 136 cases of SA to 5418 cases of non-SA over a ten-year period. Key findings include a higher average age of SA patients (61.73 years vs 35.8 years for non-SA), a higher proportion of acute on chronic appendicitis (33.1% vs 16%), and a significantly higher incidence of colorectal cancer (11.7% vs 2.2%). Despite these differences, SA remains a diagnostic challenge due to its nonspecific clinical presentation and lack of specific laboratory findings. The study also highlights the persistent prevalence of SA, accounting for 1.6%-3.4% of all appendicitis cases each year from 2013 to 2023. These findings underscore the need for enhanced awareness, early detection, and prompt treatment of SA in endemic regions. Given the association with colorectal cancer, patients with SA require thorough screening and follow-up. Further research into the pathogenesis and diagnostic markers of SA is warranted. As the global battle against schistosomiasis continues, targeted efforts to diagnose and manage SA can significantly improve patient outcomes.

Key Words: Schistosomal appendicitis; Schistosomiasis; Colorectal cancer; Misdiagnosis; Clinicopathological characteristics

Core Tip: This is a study to investigate clinical and pathological characteristics of schistosomal appendicitis (SA). SA is a serious disease, which is easy to be complicated with intestinal malignant tumors. SA has no specific clinical manifestations and laboratory tests, and the prognosis may be poor. It is more likely to be misdiagnosed and missed diagnosis in clinical work. Although chronic schistosomiasis has decreased year by year, the proportion of SA has not decreased in the past decade.

TO THE EDITOR

The recent retrospective study by Wang et al[1] sheds important light on a rare but serious condition - schistosomal appendicitis (SA). Published in the World Journal of Clinical Cases, this single-center observational study analyzed the clinical and pathological characteristics of SA over a ten-year period, providing valuable insights into this often misdiagnosed condition and its potential long-term consequences. Schistosomiasis, a parasitic disease caused by flatworms called schistosomes, affects over 250 million people worldwide[2]. While the parasites primarily reside in the intestines and liver, they can also deposit eggs in other organs, including the appendix. These eggs can trigger inflammation and fibrosis, leading to a condition known as SA[3]. Despite its potential severity and association with long-term complications, SA remains an understudied and often overlooked complication of schistosomiasis.

The study by Wang et al[1] compared 136 cases of SA to 5418 cases of non-SA (NSA), revealing several striking differences between the two conditions. Patients with SA were predominantly middle-aged and elderly males, with an average age of 61.73 years, significantly older than NSA patients at 35.8 years. This age discrepancy suggests that SA may have a more insidious onset and prolonged course compared to NSA, possibly due to the chronic nature of schistosome infection and the gradual accumulation of eggs in the appendix over time. Although acute suppurative appendicitis was the most common pathological type in both groups, SA patients had a higher proportion of acute on chronic appendicitis (33.1% vs 16%)[1], indicating a more chronic and recurrent nature of the disease.

One of the most alarming findings of the study was the significantly higher incidence of colorectal cancer in SA patients compared to NSA patients (11.7% vs 2.2%)[1]. This startling association underscores the potential role of SA in promoting intestinal malignancies and highlights the need for heightened vigilance and screening in this patient population. Prior research has suggested that schistosomiasis may drive colorectal cancer development by inducing chronic inflammation and modulating the tumor microenvironment[4]. The chronic inflammatory state triggered by schistosome eggs in the appendix may create a favorable niche for malignant transformation over time, possibly through the accumulation of DNA damage, increased cell proliferation, and altered immune responses. This finding raises important questions about the long-term consequences of SA and the need for ongoing surveillance and early intervention in affected individuals.

Despite the severity of SA, its diagnosis remains a challenge in clinical practice. The study by Wang et al[1] noted no significant differences in clinical symptoms between SA and NSA patients, making it difficult to distinguish the two conditions based on presentation alone. While white blood cell counts were mildly elevated in SA, other inflammatory and liver function markers were largely within normal ranges[1]. This lack of specific clinical and laboratory findings contributes to SA being frequently misdiagnosed or missed entirely[5]. Delayed or incorrect diagnosis can lead to inappropriate treatment, prolonged morbidity, and potentially life-threatening complications, such as bowel perforation and peritonitis. The development of novel diagnostic tools, such as improved imaging techniques or specific biomarkers, could greatly enhance our ability to detect and manage SA in a timely manner.

The persistent prevalence of SA is another concerning aspect highlighted by the study. Despite a decrease in chronic schistosomiasis cases over the years, the proportion of SA among appendicitis cases remained steady, consistently accounting for 1.6%-3.4% of all appendicitis cases each year from 2013 to 2023[1]. This finding suggests that SA continues to be a significant problem in endemic regions and underscores the need for ongoing surveillance and targeted interventions. Public health measures aimed at reducing schistosome transmission, such as improved sanitation, water treatment, and snail control, could help decrease the incidence of SA and its associated complications. Additionally, increased awareness and education among healthcare providers in endemic areas could improve the recognition and management of this condition.

The findings of Wang et al[1] have important implications for clinical practice in schistosomiasis-endemic regions. Clinicians must maintain a high index of suspicion for SA, particularly in middle-aged and elderly male patients presenting with appendicitis. Early detection and prompt treatment are crucial to prevent complications and improve outcomes. Given the association with colorectal cancer, patients diagnosed with SA should undergo thorough screening for intestinal malignancies, and long-term follow-up and surveillance strategies should be established for these high-risk individuals. The development of standardized guidelines for the management and follow-up of SA patients could help ensure consistent and appropriate care across different healthcare settings.

The study has some limitations, including its single-center design and lack of detailed imaging data[1]. Future multi-center studies with comprehensive radiological evaluations would help validate and extend these findings, providing a more robust understanding of the epidemiology and clinical features of SA. Additionally, more research into the pathogenesis of SA could uncover new diagnostic biomarkers and therapeutic targets, potentially improving our ability to diagnose and treat this condition. Studies exploring the molecular mechanisms linking schistosomiasis to colorectal carcinogenesis could also provide valuable insights into the prevention and management of this serious complication[4].

In conclusion, the study by Wang et al[1] provides valuable insights into the clinical and pathological characteristics of SA, a serious and often misdiagnosed condition associated with a higher incidence of colorectal cancer. Enhanced awareness, early detection, and prompt treatment are essential to mitigate the morbidity and mortality of SA. As we continue to battle schistosomiasis globally, targeted efforts to diagnose and manage SA can make a meaningful difference in patient outcomes. Further research is warranted to better understand the mechanisms linking schistosomiasis to colorectal carcinogenesis and to develop more effective diagnostic and therapeutic strategies for this neglected complication of a widespread parasitic disease. Only through concerted efforts in research, clinical practice, and public health can we hope to reduce the burden of SA and improve the lives of those affected by this challenging condition.