Long-term disease-free survival following preoperative diagnosis and laparoscopic radical resection for Meckel’s diverticulum adenocarcinoma: A case report

Abstract

BACKGROUND

Meckel’s diverticulum (MD) is most commonly encountered during emergency interventions for complications or as an incidental finding during an unrelated procedure. Definitive pre-operative diagnosis of MD-associated adenocarcinoma, permitting radical resection, is very rare in clinical practice.

CASE SUMMARY

A 36-year-old male presented with recurrent dark-red hematochezia. Initial gastroscopy, colonoscopy, computed tomography, and tumor marker assessments were unremarkable. A technetium-99m pertechnetate Meckel scan (Meckel scan) revealed ectopic gastric mucosa, suggesting an MD. Double-balloon enteroscopy revealed an ulcerative stricture in the ileum, and biopsy confirmed a moderately differentiated adenocarcinoma. The patient underwent laparoscopic radical small bowel resection. Histopathology confirmed pT3N0M0, stage IIA (the American Joint Committee on Cancer 8^th edition) moderately differentiated adenocarcinoma with lymphovascular invasion. Adjuvant chemotherapy was administered postoperatively. No recurrence or metastasis was observed during a 36-month follow-up.

CONCLUSION

For recurrent obscure gastrointestinal hemorrhage, combined Meckel scan and double-balloon enteroscopy is critical for diagnosing MD-associated, enabling curative resection.

Key Words: Meckel’s-diverticulum-associated adenocarcinoma; Pre-operative diagnosis; Technetium-99m pertechnetate Meckel scan; Double-balloon enteroscopy; Radical resection; Case report

Core Tip: This case report describes the pre-operative diagnosis of Meckel’s-diverticulum-associated adenocarcinoma identified by technetium-99m pertechnetate scanning and double-balloon enteroscopy. The patient underwent laparoscopic radical small-bowel resection (R0, 19 lymph nodes), based on the National Comprehensive Cancer Network guidelines, followed by adjuvant chemotherapy. Despite these high-risk features, 36 months of disease-free survival was achieved, highlighting a potential new diagnostic and therapeutic approach for this rare malignancy.

INTRODUCTION

Meckel’s diverticulum (MD) arises from the vitelline duct during embryogenesis, and it is the most prevalent congenital gastrointestinal anomaly in adults, with an estimated incidence of 2%[1]. Approximately 90% of MDs occur in the ileum, within 100 cm of the ileocecal valve, usually 3 cm in length[2]. Meckel’s-diverticulum-associated carcinoma (MDC) is very rare, affecting 0.5% to 3.2% of symptomatic patients[3,4]. Adenocarcinomas are particularly uncommon among these malignancies, accounting for only 11.04% of reported MDCs[5].

For asymptomatic MD or those with benign complications, such as hemorrhage, obstruction, or perforation, surgical approaches typically include linear stapled resection, wedge resection of the diverticulum, or limited segmental bowel resection[6]. MDC is a distinct and uncommon subtype that is often diagnosed incidentally, post-operatively. Currently, there are no standardized treatment guidelines for this condition. Most of the available literature is limited to case reports, and there is a lack of consensus regarding the extent of surgical resection and lymphadenectomy. Furthermore, the prognosis is generally poor due to frequent presentation with extensive local invasion and/or lymphatic or distant metastasis[5,7,8].

This case establishes the feasibility of obtaining a pre-operative diagnosis of MD-associated adenocarcinoma (MDA) using a combination of a technetium-99m pertechnetate Meckel scan (Meckel scan) and double-balloon enteroscopy (DBE). To our knowledge, this is the first reported case of adenocarcinoma arising in an MD that was pre-operatively diagnosed and successfully managed with laparoscopic radical resection, based on the National Comprehensive Cancer Network (NCCN) guidelines (Available from: https://www.nccn.org/). Curative-intent surgery with guideline-compliant adjuvant chemotherapy resulted in a 36-month disease-free survival. This successful strategy provides valuable insights into the guiding and standardizing of the management of this rare malignancy (Table 1)[9-11].

Table 1 Summary of reported cases of preoperative definitive diagnosis of Meckel’s diverticulum adenocarcinoma in recent years (2005-2025).

Ref.	Sex	Age, years	Symptom	Examination	Location	Treatment	Resection margin	Lymph node dissection	Pathology	Stage	Prognosis
Principe et al[9], 2022	Male	62	Melena	CE, DBE	Distal jejunum/proximal ileum	Exploratory laparotomy, small bowel resection	NA	NA	Moderately to poorly differentiated adenocarcinoma	T4N0M0	NA
Sakio et al[10], 2021	Female	45	Recurrent abdominal pain	DBE with contrast	160 cm from ileocecal valve	Bowel resection + lymphadenectomy	NA	NA	Well-differentiated adenocarcinoma	pT4aN0M0	Recurrence 2 years post-op
Sato et al[11], 2009	Male	58	Elevated tumor marker	CE, SBE	90 cm from ileocecal valve	Ileal segmental resection + regional lymphadenectomy	NA	NA	Moderately differentiated adenocarcinoma	T3	NA
Our case	Male	36	Melena	Meckel’s scan, DBE	60 cm from ileocecal valve	Radical resection of small bowel adenocarcinoma + lymphadenectomy	Negative, 20 cm proximal and distal margins	0/19	Moderately differentiated adenocarcinoma	pT3N0M0	Disease-free at 3 years

CE: Capsule endoscopy; DBE: Double-balloon enteroscopy; SBE: Single-balloon enteroscopy; NA: Not available.

CASE PRESENTATION

Chief complaints

A 36-year-old male had recurrent hematochezia for 10 months, with a new episode lasting two days.

History of present illness

Over the past 10 months, the patient has had three episodes of intermittent dark-red bloody stools. Diagnostic investigations conducted at other hospitals revealed unremarkable findings. Following symptom resolution, the patient self-discharged, on each occasion, with no definitive cause identified. The patient was admitted to our hospital for a definitive diagnosis.

History of past illness

The patient had no relevant past illnesses.

Personal and family history

The patient had no specific medical history, and there was no relevant family history.

Physical examination

The patient was 170 cm tall and weighed 100 kg, with a body mass index of 34.6 kg/m². Physical examination revealed mild periumbilical tenderness. The remainder of the examination was unremarkable.

Laboratory examinations

Positive fecal occult blood test and a hemoglobin level of 107 g/L. Other laboratory results were within normal ranges.

Imaging examinations

The Meckel scan: After injection of the radiotracer (99mTcO4-), gastric imaging was performed. An abnormal tracer concentration was observed in the mid-abdomen, which appeared as a round lesion. Over time, the tracer concentration increased slightly; however, there were no significant changes in shape or location (Figure 1). Examination conclusion: Positive imaging of ectopic gastric mucosa. Based on this, DBE was performed, and a mucosal protrusion was identified 60 cm proximal to the ileocecal valve, presenting with a “double lumen sign” (Figure 2). The distal lumen had normal ileal mucosa, whereas the proximal lumen had a circumferential ulcerated stricture occupying 75% of the bowel circumference, with exudate. The ulcer bed had raised bordering mucosa, contact hemorrhage, and a firm texture. After biopsy, the lesion was marked with India ink. Histopathological examination confirmed ileal adenocarcinoma (Figure 3) with mismatch repair proficiency (MutL homolog 1+, MutS homolog 2+, MutS homolog 6+, and postmeiotic segregation increased 2+).

Figure 1 Pre-operative technetium-99m pertechnetate Meckel scan. After intravenous administration of the radiotracer (⁹⁹mTcO₄^-), dynamic abdominal imaging was performed for 30 minutes, with one frame acquired every 5 minutes, resulting in six frames. A: Immediate gastric visualization is observed (position a in the illustration). A circular lesion with mildly increased tracer uptake is detected in the mid-abdomen (position b); B: Approximately 10 minutes post-injection, the bladder is visualized (position c), while positions a and b remain fixed with progressive accumulation of tracer; C-F: Over time, tracer uptake within the lesion is slightly increased, without notable changes in morphology or location.

Figure 2 Pre-operative double-balloon enteroscopy. A “double lumen” phenomenon is observed 60 cm from the ileocecal valve. One end represents the normal proximal intestinal lumen (position a in the illustration), with no abnormalities noted in the mucosa. The other end corresponds to the proximal blind pouch (position b in the illustration), where a circumferential stricture is present. The enteroscope was able to pass through, and a circumferential ulcer was observed at the edges. After a tissue biopsy was taken, India ink was used for marking.

Figure 3 Histopathology of specimens obtained during pre-operative double-balloon enteroscopy. A: Ileal adenocarcinoma (hematoxylin and eosin, × 40); B: Ileal adenocarcinoma (hematoxylin and eosin, × 400).

FINAL DIAGNOSIS

The final pathological diagnosis after surgical resection was MDA, pT3N0M0, Stage IIA [American Joint Committee on Cancer (AJCC) 8^th edition].

TREATMENT

After informed consent was obtained, a laparoscopic exploratory procedure was performed. A 4 cm × 8 cm diverticulum was identified approximately 60 cm from the ileocecal valve, arising from the mesenteric border of the ileum, and localized by Indian ink marking (Figure 4). Subsequently, an enlarged mesenteric lymph node, suspected to be a metastasis, was identified adjacent to the diverticulum. To achieve complete lymphadenectomy, a 5-cm midline incision was made in the upper abdomen and extended towards the root of the superior mesenteric artery. Key vascular branches were selectively ligated to minimize intraoperative blood loss. After lymph node dissection, compromised perfusion was observed in the bowel segments proximal and distal to the lesion. To secure well-vascularized anastomotic margins and to reduce the risk of post-operative leakage, the resection was extended to include only segments with a confirmed normal blood supply, resulting in final margins of approximately 20 cm on both sides. The bowel was transected using a linear stapler, and the specimen was subsequently submitted for histopathological examination. A side-to-side anastomosis of the proximal and distal ileum was performed using microsutures. The muscular layer was reinforced with purse-string sutures to invert the residual ends, and the mesenteric defect was closed. Final histopathological examination confirmed a 1.5-cm ulcerative moderately-differentiated small intestinal adenocarcinoma confined to the intestinal wall (Figure 5). The tumor invaded the subserosa without serosal penetration. Lymphovascular invasion was observed, with no perineural invasion. The surgical margins were negative. All 19 examined regional lymph nodes were metastasis-free. Immunohistochemical profile: Caudal-type homeobox 2 (+)/cytokeratin 20 (-)/cytokeratin 7 (+); cyclooxygenase-2 (+)/human epidermal growth factor receptor 2 (immunohistochemistry); Ki-67 90%; mismatch repair proteins intact (MutL homolog 1+, MutS homolog 2+, MutS homolog 6+, and postmeiotic segregation increased 2+). The final diagnosis was MDA pT3N0M0, stage IIA (AJCC 8^th edition). Given the lymphovascular invasion (high-risk feature), adjuvant chemotherapy with four cycles of oxaliplatin and capecitabine (oxaliplatin 130 mg/m² day 1, capecitabine 1000 mg/m², twice a day, day 1-14) followed by six months of capecitabine monotherapy was initiated.

Figure 4 Gross specimen from laparoscopic radical small bowel cancer resection. A: The resected Meckel’s diverticulum measured approximately 5 cm in its short diameter. Indian ink marking is observed at the junction between the diverticulum and the adjacent bowel. The diverticulum is approximately 20 cm from each resection margin; B: The diverticulum measures approximately 5 cm in its long axis.

Figure 5 Histopathology of specimens from laparoscopic radical small bowel cancer resection. A: Ileal ulcerated moderately differentiated adenocarcinoma (hematoxylin and eosin, × 40); B: Ileal ulcerated moderately differentiated adenocarcinoma (hematoxylin and eosin, × 400).

OUTCOME AND FOLLOW-UP

The patient recovered uneventfully and was discharged on post-operative day 8. No tumor recurrence or metastasis was detected during 36 months of follow-up. The surveillance protocol was as follows: In the first post-operative year, hematological tests, including tumor markers, were performed every three months, abdominal contrast-enhanced computed tomography or total gastrointestinal imaging was performed every six months, and DBE was performed annually. From the second year onwards, the frequency of hematological tests was reduced to every six months, while the schedules for imaging and DBE remained unchanged. In addition, the patient was instructed to return immediately for reassessment if there were symptoms such as melena or hematochezia.

DISCUSSION

MDCs are frequently diagnosed incidentally during surgery because of their insidious presentation and the absence of specific diagnostic tools. At diagnosis, the disease is often advanced, resulting in a poor prognosis[8]. Carcinoid tumors represent the most common MDC, followed by gastrointestinal stromal tumors, leiomyosarcomas, and rarer adenocarcinomas of gastric/intestinal origin[12-14]. Despite their lower incidence, adenocarcinomas occur at younger ages (mean 55.9 years) and have a poorer prognosis, with a median overall survival of 13 months[5]. Surveillance, Epidemiology, and End Results database analysis revealed an increasing incidence of MDA malignancies, predominantly in males, but increasing more rapidly in females. MD confers a 70-fold higher cancer risk than the adjacent ileum, with the incidence increasing with age[5].

The current pre-operative diagnostic modalities for MDC are limited. While contrast-enhanced abdominal computed tomography/magnetic resonance imaging may detect an MD, uncomplicated MDs are frequently overlooked and misidentified as bowel loops[15]. Typically, esophagogastroduodenoscopy and colonoscopy cannot access the MDs. The Meckel scan effectively detects the gastric mucosa in an MD but fails to identify malignant lesions[16]. Capsule endoscopy visualizes the MD orifice, but it carries risks of entrapment within the diverticulum or stenotic segments, with an inability to obtain biopsies or exclude missed lesions[10,17]. Small-bowel enteroscopy offers superior diagnostic value, enabling direct visualization, targeted biopsies, and minimizing procedure-related risk of obstruction, which are particularly advantageous for the diagnosis of MDC[18]. Similar to our case, DBE is critical for pre-operative confirmation of MDC[9,10]. Furthermore, India ink marking was performed to enable identification of the lesion to facilitate intra-operative localization.

MDCs typically present with complications such as gastrointestinal hemorrhage, perforation, or bowel obstruction[19], requiring emergency admission. Clinical deterioration often necessitates urgent surgical intervention. As pre-operative diagnosis of MDC remains elusive, surgical interventions are frequently limited to diverticulectomy or segmental resection without oncological principles, such as adequate margins or lymphadenectomy[5]. Contemporary case reports describe negative margins and lymph node sampling, but fail to quantify resection margin distances[9,10]. Although Hendrickx et al[7] reported a case of metastasis-free lymph nodes (0/5), inadequate lymph node dissection still poses a risk, because lymph node metastasis is a strong predictor of prognosis[20]. For MDCs, failure to accurately locate the tumor or incomplete resection of the tumor, resulting in residual lesions post-operatively, leads to a poorer prognosis. Re-operation is often ineffective, and adjuvant chemotherapy does not provide significant benefits[21]. Intraoperative frozen-section histopathology may also delay decision-making. In this case, early presentation allowed for a pre-operative diagnosis of MDC. Despite the lack of specific guidelines, the NCCN small-bowel cancer principles of R0 resection with > 20 cm margins and extended lymphadenectomy were applied. Histopathological examination confirmed no nodal metastasis (0/19), aligning with the NCCN recommendations (≥ 10 cm margins, ≥ 8 nodes).

The anatomical location and ligation of vessels close to the mesenteric root are crucial for complete lymph node dissection. Although radical dissection can improve survival, the division of vessels at their roots may compromise blood flow, increasing the risk of anastomotic ischemia and fistulas. To reduce this risk, surgeons may extend resection to obtain a well-perfused segment for anastomosis[22-24]. Extensive resection can cause malabsorption of nutrients and electrolyte imbalance[25]; however, most nutrients are absorbed by the proximal small intestine, which can adapt to partially offset the reduced absorption area. Resection of ≤ 50% of the small intestine is generally tolerated, particularly if the ileocecal valve is preserved[26]. Surgeons must balance oncological radicality with bowel preservation. In this case, although the resection exceeded the guideline-recommended margin (> 20 cm vs NCCN recommendation of 10 cm), it yielded a higher lymph node count (19 vs NCCN recommendation of ≥ 8). At the three-year post-operative follow-up, the patient had no electrolyte disturbances, chronic diarrhea, or weight loss (body mass index = 28.7 kg/m²). To the best of our knowledge, this is the first reported case of MDA definitively diagnosed pre-operatively and treated with laparoscopic radical surgery. Post-operative histopathological examination revealed an intravascular cancer thrombus, which is a risk factor for recurrence and metastasis. The patient subsequently received adjuvant chemotherapy and remained free of recurrence or metastasis during the three-year follow-up. For post-operative surveillance of MDA, whenever feasible, adherence to the NCCN guidelines is recommended: Clinical evaluation every three months during the first two years with imaging as indicated, every six months from years three to five, and annually thereafter. If patient compliance is suboptimal, the follow-up schedule should be appropriately adjusted.

CONCLUSION

In conclusion, the successful 36-month disease-free survival in this case underscores that pre-operative diagnosis of MDA is achievable using a combination of a Meckel scan and DBE, enabling radical resection based on oncological principles. We recommend that this diagnostic approach be considered for patients with obscure gastrointestinal hemorrhage after initial negative routine evaluations. This strategy will inform our practice by prioritizing small bowel assessment and structured lymphadenectomy in similar presentations. Further multicenter studies are required to establish standardized pre-operative diagnostic pathways and surgical guidelines for this rare malignancy.