Amyand’s hernia associated with acute appendicitis and incidental sessile serrated lesion in a recurrent incarcerated inguinal hernia: a case report

Abstract

Introduction

Amyand’s hernia is defined as the presence of the vermiform appendix within an inguinal hernia sac. The condition was first described by Claudius Amyand in 1735 when he performed the first successful appendectomy in a patient with a perforated appendix contained within an inguinal hernia sac [1]. Although Amyand's hernia accounts for ~0.1%–1.3% of all inguinal hernias, the occurrence of acute appendicitis within the hernia sac is considerably rarer, with reported incidences ranging from 0.07% to 0.13% [2–8].

The clinical presentation is highly variable and often resembles incarcerated or strangulated inguinal hernia. Patients may present with groin pain, irreducible swelling, nausea, vomiting, bowel obstruction, or signs of systemic inflammation [3–8]. Consequently, preoperative diagnosis remains difficult and most cases are identified unexpectedly during surgical exploration [5, 6, 8].

Several classification systems have been proposed to guide management, among which the Losanoff and Basson classification remains the most widely accepted. This system categorizes Amyand’s hernia according to the inflammatory status of the appendix and associated abdominal pathology, thereby facilitating appropriate surgical decision-making [2].

An additional challenge arises when unusual pathological findings are identified in appendectomy specimens. Sessile serrated lesions (SSLs) of the appendix are uncommon entities that have gained increasing attention because of their potential role in the serrated pathway of colorectal carcinogenesis. Their coexistence with Amyand's hernia is exceptionally rare.

We present a case of recurrent incarcerated Amyand's hernia containing an inflamed appendix and cecal component in a 55-year-old man. Histopathological examination revealed acute appendicitis associated with a sessile serrated lesion and retention cyst without dysplasia or malignancy. This report is presented in accordance with the SCARE 2023 guidelines [9].

Case presentation

A 55-year-old homeless male presented to the emergency department with a 24-hour history of progressive right groin pain associated with nausea and multiple episodes of vomiting. The patient reported a longstanding recurrent right inguinal hernia that had previously been reducible but had become irreducible and increasingly painful during the preceding day. He had undergone a prior right inguinal hernia repair several years earlier; however, no operative records were available because of his social circumstances. No significant medical history could be reliably obtained.

Upon admission, the patient was hemodynamically stable. Physical examination demonstrated mild abdominal distension and a tender irreducible right inguinal swelling extending toward the scrotum. No overlying skin erythema, cellulitis, discoloration, or crepitation was noted. Mild tenderness was present in the hypogastric region and right inguinal area. Bowel sounds were decreased.

Laboratory investigations revealed a white blood cell count of 8.3 × 10⁹/L with 65.2% neutrophils, hemoglobin of 13 g/dL, and platelet count of 404 × 10⁹/L. C-reactive protein was mildly elevated at 8.7 mg/L. Additional biochemical investigations demonstrated serum glucose of 110 mg/dL, urea of 28 mg/dL, creatinine of 0.7 mg/dL, sodium of 135 mEq/L, potassium of 4.0 mEq/L, AST of 25 U/L, ALT of 11 U/L, ALP of 244 U/L, amylase of 21 U/L, and lipase of 15 U/L. Coagulation studies showed PT of 14.5 seconds, PTT of 35 seconds, and INR of 1.3.

Abdominal radiography demonstrated multiple dilated small bowel loops measuring up to 4.2 cm in diameter, suggestive of mechanical bowel obstruction (Fig. 1). Ultrasonographic examination of the inguinoscrotal region identified a right inguinal hernia sac measuring ~42 × 21 mm containing adipose tissue and bowel loops, with enlargement during the Valsalva maneuver. The findings were interpreted as an incarcerated inguinal hernia. Both testes appeared normal in size and echotexture with preserved vascular flow on Doppler examination, excluding complete testicular torsion. Additional bowel loops were visualized within the left hemiscrotum; however, accurate measurement of the hernia sac was limited by its extent.

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After initial resuscitation, a nasogastric tube was inserted for gastric decompression, and intravenous antibiotics were administered. Owing to the clinical diagnosis of incarcerated recurrent inguinal hernia with bowel obstruction, emergency surgical exploration was undertaken under general anesthesia.

Following standard skin preparation and draping, a right oblique inguinal incision was made. Dissection through the subcutaneous tissue revealed extensive adhesions from the previous operation (Fig. 2). Careful adhesiolysis was performed until the hernia sac was fully exposed. Upon opening the sac, an inflamed vermiform appendix accompanied by a cecal component was identified within the hernia sac, establishing the diagnosis of Amyand's hernia (Fig. 3). Dilated and inflamed bowel loops were also noted.

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The adhesions surrounding the incarcerated contents were meticulously released, and the appendix was mobilized. The internal ring was partially enlarged to facilitate safe reduction of the hernia contents. Appendectomy was subsequently performed following ligation of the appendiceal artery using silk ties. The appendiceal stump was secured with chromic sutures. The appendix and cecal component were then reduced into the abdominal cavity.

Because active appendiceal inflammation was present, prosthetic mesh implantation was avoided. Reconstruction of the posterior wall of the inguinal canal was therefore accomplished using a modified Bassini tissue repair. The external oblique aponeurosis was closed, followed by layered closure of the subcutaneous tissue using absorbable sutures and skin approximation in standard fashion.

Gross postoperative recovery was uneventful. Oral intake was gradually resumed following return of bowel function. The patient experienced progressive resolution of symptoms and was discharged on postoperative day three in good general condition.

Histopathological examination of the appendix demonstrated acute appendicitis associated with a sessile serrated lesion and retention cyst. No evidence of dysplasia or malignancy was identified. Examination of the excised hernia sac revealed fibro-adipose tissue with congested blood vessels. Given the unexpected identification of a serrated lesion, colonoscopic evaluation was recommended. Follow-up colonoscopy performed three months after surgery revealed no evidence of synchronous colorectal polyps, advanced adenomas, or colorectal malignancy.

Discussion

Amyand’s hernia is a rare surgical entity characterized by the presence of the vermiform appendix within an inguinal hernia sac. Although inguinal hernia repair is among the most commonly performed surgical procedures worldwide, Amyand's hernia accounts for only ~0.1%–1.3% of inguinal hernias [3–8]. The presence of acute appendicitis within the hernia sac is even more uncommon, with reported incidences ranging from 0.07% to 0.13%. Since its first description by Claudius Amyand in 1735 [1], fewer than a few hundred well-documented cases have been reported in the literature, highlighting the rarity of this condition [7].

The pathophysiological mechanisms responsible for the development of appendicitis within an Amyand’s hernia remain incompletely understood. Several hypotheses have been proposed. One theory suggests that repetitive trauma resulting from intermittent incarceration may compromise blood flow to the appendix, leading to ischemia and subsequent inflammation. Another hypothesis proposes that compression at the hernia neck causes luminal obstruction, bacterial overgrowth, and appendiceal inflammation. In addition, chronic adhesions between the appendix and hernia sac may predispose to repeated episodes of irritation and inflammatory change. In the present case, extensive adhesions encountered during surgery and the history of recurrent hernia support the possibility that chronic incarceration contributed to the development of appendiceal inflammation.

Amyand’s hernia occurs predominantly in males and almost always involves the right side because of the normal anatomical position of the cecum and appendix. Left-sided Amyand’s hernias are exceedingly rare and are usually associated with anatomical abnormalities such as situs inversus totalis, intestinal malrotation, or a mobile cecum [5–8]. The present patient demonstrated the typical right-sided presentation described in most reported cases.

Clinical diagnosis remains challenging because symptoms are nonspecific and frequently mimic incarcerated or strangulated inguinal hernia. Patients commonly present with painful groin swelling, irreducibility, nausea, vomiting, and varying degrees of bowel obstruction [3–8]. Classical signs of acute appendicitis are often absent because the inflammatory process is confined within the hernia sac. Consequently, most diagnoses continue to be established intraoperatively [5, 6, 8]. Our patient presented with progressive groin pain, vomiting, and radiological evidence of small bowel obstruction, findings that strongly suggested incarceration but did not specifically indicate the presence of appendicitis within the sac.

Modern imaging techniques have improved preoperative diagnostic accuracy. Ultrasonography may occasionally demonstrate a blind-ending tubular structure within the hernia sac, while computed tomography is considered the most accurate modality for identifying Amyand’s hernia [10]. CT can clearly demonstrate the appendix entering the inguinal canal and can simultaneously assess inflammatory changes, bowel obstruction, perforation, and associated intra-abdominal pathology. Nevertheless, emergency surgery is often required before advanced imaging can be obtained, particularly in patients presenting with incarcerated hernias and signs of obstruction. In the present case, ultrasonography demonstrated an incarcerated hernia containing bowel loops but failed to identify the appendix, consistent with many previously reported cases [10].

Management of Amyand’s hernia remains a subject of ongoing discussion. The most widely accepted treatment algorithm is based on the classification proposed by Losanoff and Basson [2]. Type I hernias contain a normal appendix and can generally be managed by reduction of the appendix followed by mesh hernioplasty. Type II hernias contain an inflamed appendix confined to the hernia sac without evidence of abdominal sepsis and are typically managed with appendectomy and primary tissue repair. Type III hernias involve perforated appendicitis or abdominal sepsis and require laparotomy in addition to appendectomy and hernia repair. Type IV hernias are associated with additional intra-abdominal pathology and require individualized treatment strategies [2].

Our patient was classified as having a Type II Amyand’s hernia because acute appendicitis was confined to the hernia sac without perforation, generalized peritonitis, or intra-abdominal sepsis. Accordingly, appendectomy and modified Bassini repair were performed [2]. Avoidance of prosthetic mesh in this setting remains consistent with current surgical recommendations because implantation of mesh within a contaminated operative field may increase the risk of wound infection, chronic mesh infection, fistula formation, and hernia recurrence requiring reoperation [2, 6].

Another important aspect of this case is the recurrent nature of the hernia. Recurrent Amyand’s hernia is considerably less frequently reported than primary Amyand’s hernia [7, 8]. Previous surgery often results in fibrosis, distortion of normal anatomy, and dense adhesions, which can increase operative complexity and potentially contribute to incarceration [7, 8]. The extensive adhesions encountered during surgical exploration in our patient support this observation. Recurrent incarcerated Amyand’s hernia therefore represents an especially uncommon clinical presentation.

The most distinctive feature of the present case was the incidental histopathological identification of a sessile serrated lesion (SSL) associated with acute appendicitis and retention cyst formation. Traditionally, these lesions were referred to as sessile serrated adenomas or sessile serrated polyps. However, the current World Health Organization (WHO) Classification of Digestive System Tumours recommends the term sessile serrated lesion because it more accurately reflects the biological characteristics of these lesions and avoids implying the presence of conventional adenomatous dysplasia [11].

Sessile serrated lesions are characterized histologically by architectural distortion of crypts, basal crypt dilatation, horizontal growth of crypt bases, and serration extending to the crypt base. In the colorectum, SSLs are now recognized as important precursor lesions within the serrated neoplasia pathway. This pathway differs from the conventional adenoma-carcinoma sequence and is commonly associated with BRAF mutations, CpG island methylator phenotype (CIMP), and epigenetic alterations that may ultimately lead to colorectal carcinoma [12–16].

Although serrated lesions of the appendix are considerably less common than those arising in the colon, increasing evidence suggests that they may share similar molecular and pathological features [12, 14, 17, 18]. Appendiceal SSLs are frequently discovered incidentally following appendectomy performed for acute appendicitis, suspected appendiceal neoplasms, or other surgical indications. Because these lesions are uncommon, their true incidence and natural history remain poorly defined [12, 17, 18]. Nevertheless, several studies have reported an association between appendiceal serrated lesions and synchronous or metachronous colorectal neoplasia, raising concerns regarding their potential clinical significance [12, 17, 18].

Importantly, no dysplasia or malignancy was identified in our patient. The absence of dysplasia generally indicates a favorable prognosis; however, recognition of the lesion remains clinically important. Identification of an appendiceal SSL may provide an opportunity for early colorectal screening and surveillance. For this reason, several authors have suggested consideration of colonoscopic evaluation following the diagnosis of appendiceal serrated lesions, particularly in middle-aged and older adults [12, 17, 18].

In the present case, colonoscopy performed three months after surgery demonstrated no evidence of synchronous colorectal polyps, advanced adenomas, or colorectal malignancy. This finding is reassuring and suggests that the appendiceal lesion was isolated. Nevertheless, the performance of postoperative colonoscopy strengthened the overall management strategy and provided additional clinical information that may be valuable for long-term patient care [12, 17, 18].

The coexistence of recurrent incarcerated Amyand’s hernia, acute appendicitis, sessile serrated lesion, and retention cyst within the same specimen represents an exceptionally uncommon combination of findings. To the best of our knowledge, only a limited number of reports have documented appendiceal serrated lesions in association with Amyand’s hernia. This unusual pathological combination adds novelty to the present case and further emphasizes the importance of routine histopathological examination of all appendectomy specimens, regardless of the apparent intraoperative diagnosis.

Ultimately, this case illustrates several important clinical lessons. First, Amyand’s hernia should remain part of the differential diagnosis of incarcerated inguinal hernia despite its rarity. Second, definitive diagnosis often depends upon careful intraoperative assessment [5, 6, 8]. Third, adherence to established management algorithms such as the Losanoff classification facilitates appropriate surgical decision-making [2]. Finally, meticulous pathological examination may reveal unexpected lesions with potential implications for future surveillance and patient management [11–20].

Conclusion

Amyand’s hernia remains a rare and diagnostically challenging condition that is frequently indistinguishable from incarcerated inguinal hernia before surgery [3–8]. Prompt operative intervention is essential to prevent complications such as bowel ischemia, perforation, and sepsis [2, 6]. The present case demonstrates successful management of a recurrent incarcerated Losanoff type II Amyand’s hernia using appendectomy and modified Bassini tissue repair.

Furthermore, the incidental identification of a sessile serrated lesion and retention cyst within the appendix highlights the importance of routine histopathological examination of appendectomy specimens. Although no dysplasia or malignancy was identified, recognition of such lesions may have implications for colorectal surveillance [11–18]. Follow-up colonoscopy in our patient demonstrated no synchronous colorectal neoplasia. This case contributes to the limited literature describing the coexistence of Amyand’s hernia and appendiceal serrated lesions and emphasizes the importance of individualized management based on intraoperative findings and pathological evaluation.

Acknowledgements

The authors would like to thank the Clinical Research Development Unit (CRDU) of Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran, for their support, cooperation, and assistance throughout the period of study. The authors also wish to extend their special thanks to Mr.Reza Dodangeh and Dr.Seyed Mahdi Tabatabaei Naeini for their valuable guidance and dedicated support in improving this manuscript.

Conflicts of interest

None declared.

Funding

None declared.

References