The infant’s story began with vomiting that his parents could not ignore. There was no diarrhea, and nothing in the early course suggested simple enteritis. What alarmed clinicians at the first hospital was the character of the vomit: it was green and bile-like, a warning that something might be obstructing the bowel downstream of the stomach and duodenum. On arrival, the boy’s vital signs were relatively reassuring. His temperature was 37.4 degrees Celsius, his pulse 124 beats per minute, his blood pressure 79 over 48 millimeters of mercury, and his respiratory rate 41 breaths per minute. His peripheral oxygen saturation was a perfect 100 percent on room air. But the physical examination told a more troubling story. His vitality was slightly decreased, his abdomen was distended, and his bowel sounds were diminished.

Curiously, despite what would turn out to be dying bowel inside his abdomen, the infant showed almost no signs of peritoneal irritation, the rebound tenderness and guarding that usually accompany a surgical emergency of this kind. That absence would later prove to be one of the most instructive features of the case. What the boy did have was massive hematochezia, the passage of bloody stool, which is a clinical finding that strongly suggests bowel necrosis. Laboratory tests revealed early-stage inflammation, with a white blood cell count of 15,900 per microliter and a C-reactive protein level of 3.84 milligrams per deciliter, along with slight anemia at a hemoglobin of 12.4 grams per deciliter. Arterial blood gas analysis showed a pH of 7.48 with a bicarbonate level of 19.3 millimoles per liter, a base excess of minus 2.6, and a lactate of 1.0, a pattern consistent with compensated metabolic acidosis.

Abdominal radiography demonstrated findings consistent with ileus, the failure of the bowel to propel its contents, prompting the team to perform contrast-enhanced computed tomography. That scan revealed a closed-loop configuration, and based on a diagnosis of strangulated ileus, the infant was emergently transferred to the authors’ hospital. Only later, and then retrospectively, did reviewers recognize that the CT images had actually shown a bowel-within-bowel appearance that had not been appreciated preoperatively. More importantly, the images displayed a characteristic double-enhanced layer: an inner layer representing necrotic intestine, and an outer layer corresponding to viable colon with preserved blood flow, with fluid accumulation noted between them. The inner layer appeared discontinuous, and frond-like loops of small bowel were visible, resembling a multipolypoid mass.

Ultrasonography, the first-line diagnostic modality in children with suspected intussusception, had failed to show the classic target or doughnut signs. Instead, color Doppler imaging identified only an absence of blood flow within the intestinal wall, a finding that in retrospect resulted from hemorrhagic and necrotic tissue. The authors explain the missing target sign through three pathological mechanisms: necrosis and thickening of the incarcerated bowel, necrosis and dissolution of the mesenteric fat and vessels, and distortion of the bowel configuration caused by the necrotic mesentery. When the normal layered anatomy of the intussusceptum is destroyed in this way, the concentric rings that radiologists rely on simply cease to exist, and the examination that is usually near-definitive becomes misleadingly normal or nonspecific.

The differential diagnosis at the time included internal hernia and strangulated ileus caused by a Meckel’s band. The team also considered a vaccine-related cause. In Japan, the rotavirus vaccine is administered within 14 weeks of birth, and this patient had received it; however, more than a month had passed since vaccination, making a side effect unlikely. With no definitive diagnosis established, the decision was made to proceed with emergency surgery. A nasogastric tube was not inserted before transfer because the child went straight to the operating room, and by the time the tube was placed he had already vomited a small amount of contents. What followed was an operation that tested the surgeons’ ability to read anatomy that had been turned inside out.

Upon opening the abdomen, the surgical team could not immediately identify necrotic bowel, precisely because the dead segment was hidden inside living tissue. Only careful palpation revealed a firm mass within the colon, at which point an intraluminal colonic lesion was suspected for the first time and a colotomy was performed. Necrotic bowel was indeed found within the colonic lumen, confirming the diagnosis of intussusception. Manual reduction using Hutchinson’s maneuver was unsuccessful, so the surgeons resected a 30-centimeter section of small intestine including the necrotic portion. The colon was spared, and the ileocecal valve was preserved. A double-barrel ileostomy was created, with the anal-side small bowel brought out as a mucous fistula. Two months later the stoma was closed, and at one-year follow-up the boy was tolerating oral feeding, growing appropriately, and free of recurrence, with abdominal radiography showing no evidence of obstruction.

Examination of the resected specimen settled the anatomical question: the ileum had invaginated into the colon, confirming an ileoileocolic-type intussusception, with the mesenteric vessels and fat within the invaginated segment completely necrotic and liquefied. This subtype is the crux of the case. The most common form of intussusception in children is the ileocolic type, which can usually be diagnosed easily on ultrasound. The ileoileocolic type is rare, harder to diagnose, and associated with a significantly higher incidence of bowel necrosis. Its success rate for nonoperative reduction is only about 10 percent, which is why the authors argue that it should be diagnosed promptly and treated with surgical intervention rather than reduction by high-pressure enema. In this subtype, the necrotic segment sits within normal bowel, which is exactly why identifying the dead tissue was so time-consuming in the operating room; anticipating it preoperatively, the authors note, would have shortened the operation and reduced the burden on the patient.

The case also resolves a physiological puzzle: why a child with necrotic bowel lacked peritoneal signs. The authors suggest that in intussusception, exudate from the necrotic segment is released into the colonic lumen rather than into the peritoneal cavity, blunting the inflammatory irritation of the abdominal lining that usually signals disaster. Meanwhile, more than 90 percent of childhood intussusception cases are idiopathic, with roughly 5 percent attributable to a pathological lead point such as lymphoid hyperplasia, Meckel’s diverticulum, duplication cysts, intestinal polyps, mesenteric lymphadenopathy, lymphoma, prior surgery, or trauma. In this infant, no cause could be determined, and the small number of reported ileoileocolic cases precludes identifying any region-specific pattern.

Perhaps the most consequential imaging lesson concerns the double-enhanced layer itself. On contrast-enhanced CT, the bowel wall presumed to be necrotic exhibited hyperattenuation and looked deceptively similar to viable bowel, an appearance the authors attribute to capillary hemorrhage originating from the necrotic bowel wall. The team initially interpreted the inner wall as living tissue; it was in fact necrotic mucosa stained by hemorrhage. Misreading this hyperattenuating inner layer as viable intestine could lead clinicians to underestimate the extent of bowel death and delay surgery, with potentially catastrophic consequences. Prior reports had described a multipolypoid appearance on contrast enema and frond-like loops on ultrasonography in this condition, but the authors believe this is the first description of a double-enhanced layer on contrast-enhanced CT in ileoileocolic intussusception mimicking viable bowel. For emergency physicians, radiologists, and pediatric surgeons, the message is stark: when the target sign is missing but a child is sick, the absence of a classic finding may itself be the finding, and the brightest layer on the scan may be the deadest bowel in the abdomen.

Subject of Research: Ileoileocolic intussusception with atypical imaging findings in a pediatric patient

Article Title: Ileoileocolic Type Intussusception With Double Enhanced Layer Sign in a Pediatric Patient: A Case Report

Article References: Sakamoto, N., Take, Y., Nemoto, Y., Ono, K., Tanaka, Y., & Masumoto, K. (2026). Ileoileocolic Type Intussusception With Double Enhanced Layer Sign in a Pediatric Patient: A Case Report. Clinical Case Reports, 14(10), Article e73707. https://doi.org/10.1002/ccr3.73707

Image Credits: AI Generated

DOI: 10.1002/ccr3.73707

Keywords: intussusception, pediatrics, ileoileocolic, contrast-enhanced CT, target sign, bowel necrosis, ultrasonography, emergency surgery, strangulated ileus, case report, double enhanced layer sign, ileostomy

The patient arrived at the hospital with sudden, severe abdominal pain that had begun several hours earlier, accompanied by three days of vomiting and an inability to pass stool, the classic signature of a bowel obstruction. His history contained one crucial clue: a reducible inguinal hernia on the left side, a lump he had presumably been able to push back into the abdomen until now. He had never smoked, and his family and personal medical histories were otherwise unremarkable, offering no hint of the malignancy lurking in his pelvis. What transformed a routine hernia presentation into an emergency was the sudden irreducibility of the lump and the rapid onset of systemic illness.

On examination, the clinical picture was alarming. The man was tachycardic, with a heart rate of 105 beats per minute, and febrile at 38.5 degrees Celsius, although his blood pressure remained stable. A bulge was clearly visible in the left inguinal region and could not be reduced by manual manipulation, indicating that the hernia contents were trapped. Palpation of the abdomen revealed severe tenderness with rebound tenderness, a finding that signals peritoneal irritation and, in this context, suggests that bowel contents have already leaked into the abdominal cavity. Laboratory tests showed leukocytosis, with a white blood cell count of 14,900 per microliter, of which 85 percent were neutrophils, the front-line cells of the acute inflammatory response. His hemoglobin and platelet counts were normal, and his coagulation profile showed no abnormalities.

A contrast-enhanced computed tomography scan provided the decisive diagnosis. The images demonstrated an incarcerated sigmoid colon containing a malignant tumor within the left inguinal hernia sac, along with significant pneumoperitoneum, free air in the abdominal cavity that is a hallmark of gastrointestinal perforation. Coronal reconstructions confirmed the extension of the tumor-bearing sigmoid segment down into the hernia sac. The combination of generalized peritonitis and imaging evidence of perforation meant that attempting to manually reduce the hernia would have been dangerous, potentially forcing contaminated material back into the peritoneal cavity. Instead, after blood samples were drawn and fluid resuscitation initiated, the patient was rushed to the operating room for an emergency midline laparotomy.

What the surgeons found during exploration explained the paradox of the imaging. There was a perforation in the cecum, the pouch where the small intestine joins the colon, far from the hernia itself. The sigmoid mass was strangulated inside the left inguinal hernia sac, cutting off its own blood supply and blocking the bowel lumen. Because the tumor had obstructed the distal colon while the ileocecal valve, the one-way gate between the small and large intestine, continued to function, gas and fluid secreted upstream had nowhere to escape. The colon became a sealed pressure chamber, and the cecum, subject to the highest wall tension, ultimately burst. The team performed a total colectomy with an end ileostomy, closing the rectal stump using the Hartmann technique, and ligated the inferior mesenteric vascular pedicle high to permit an adequate lymph node dissection in line with standard oncologic principles.

The choice of total colectomy rather than a limited resection reflected the state of the right colon, which had suffered severe ischemic and distension-related changes from the prolonged obstruction. An end ileostomy, in which the end of the small intestine is brought through the abdominal wall to discharge waste into a bag, was selected because the emergency setting and the patient’s advanced age substantially raised the risk of a primary anastomosis, a surgical reconnection that could leak under such unfavorable conditions. The postoperative course was uneventful. The patient spent time in the surgical intensive care unit and was discharged after five days in good condition with stable vital signs, a remarkably smooth recovery given the gravity of his initial presentation.

Pathology confirmed the suspicion raised on imaging: an adenocarcinoma, the most common type of colorectal cancer, with involvement of 2 of the 15 resected lymph nodes, corresponding to a stage classified as T3N1, meaning the tumor had grown through the bowel wall and spread to regional nodes but no further. A metastatic workup detected no distant spread. The patient subsequently completed a course of chemotherapy, and once imaging confirmed the absence of metastasis, his ileostomy was surgically closed, restoring normal intestinal continuity. At follow-up, no evidence of recurrence or postoperative complications was found, and the patient reported significant improvement in his symptoms and satisfaction with the outcome.

The physiology behind this case illuminates why the cecum is the colon’s weakest link under pressure. The cecum has the largest diameter of any colonic segment, and according to Laplace’s law, wall tension rises with diameter for a given intraluminal pressure, meaning the cecal wall bears more stress than narrower segments downstream. Its wall is also thinner than the rest of the colon, and its blood supply is comparatively limited, making it vulnerable both to mechanical rupture and to ischemic injury when distension compresses its vessels. Colonic perforation from cancer is itself uncommon, occurring in roughly 3 to 8 percent of obstructing cases, and it typically happens at the cecum when obstruction develops elsewhere. Most often the obstruction is caused by inflammatory diseases such as Crohn’s disease or ulcerative colitis, or by tumors, and occasionally tumor cell infiltration directly weakens the wall at the site of the cancer itself.

Tumors found in or near hernia sacs are classified by location and origin as saccular, intrasaccular, or extrasaccular. Intrasaccular neoplasms arise from adjacent abdominal organs, most frequently the sigmoid colon, and herniate into the sac; this occurs in roughly 1 in every 200 cases of colorectal cancer. The simultaneous occurrence of a colorectal tumor inside an inguinal hernia sac has an estimated prevalence of only 0.5 percent. Inguinal hernia itself is anything but rare, affecting about 7.7 percent of the worldwide population, with prevalence climbing from 0.25 percent in 18-year-olds to 4.2 percent in those over 75, and affecting roughly 27 percent of men compared with 3 percent of women. The sac most commonly contains bowel loops, omentum, or bladder, and while many hernias remain asymptomatic, they can progress to obstruction, incarceration, strangulation, and, in prolonged cases, perforation of the strangulated bowel wall with local peritonitis.

What distinguishes this report from previously published cases is the geography of the disaster. In most reported instances of colorectal cancer associated with inguinal hernias, the complications, whether obstruction or perforation, occur in the herniated, tumor-bearing sigmoid segment itself, sometimes infiltrating nearby structures such as the spermatic cord. Prior reports, including a series of 38 cases of colon cancer incarcerated in hernias and individual accounts of perforated sigmoid tumors covered by hernia sac, described damage confined to the trapped segment. Here, the sigmoid adenocarcinoma was strangulated in the hernia, but the rupture occurred in the cecum, anatomically distant from the tumor, pointing to an indirect mechanism of closed-loop obstruction and markedly elevated intraluminal pressure rather than direct tumoral invasion or localized ischemia. For clinicians, the lesson is sobering: an irreducible groin hernia in an older patient with obstructive symptoms and peritoneal signs may conceal a malignancy, and the most life-threatening injury may lie far from the lump itself. Prompt CT imaging and emergency laparotomy, rather than attempts at reduction, proved decisive in saving this patient’s life.

Subject of Research: Cecal perforation caused by sigmoid colon cancer incarcerated in an inguinal hernia

Article Title: A Case Report of Cecal Perforation Due to Sigmoid Tumor Incarceration in Inguinal Hernia

Article References: Ahmadinejad, M., Tajik, A., Soltani, H., Maleki, H., & Bagherpour, J. Z. (2026). A Case Report of Cecal Perforation Due to Sigmoid Tumor Incarceration in Inguinal Hernia. Clinical Case Reports, 14(10), Article e73661. https://doi.org/10.1002/ccr3.73661

Image Credits: AI Generated

DOI: 10.1002/ccr3.73661

Keywords: inguinal hernia, sigmoid colon cancer, cecal perforation, bowel obstruction, adenocarcinoma, colectomy, ileostomy, closed-loop obstruction, colorectal surgery, case report, peritonitis, emergency surgery