Idiopathic localised dilatation of the intestine in adults

Abstract

Idiopathic localised dilatation of the intestine (ILDI) presenting in adults is rare and difficult to diagnose. Only 18 cases have been reported in the literature. We report a case of a 32-year-old woman presenting with abdominal pain and intermittent small bowel obstruction. After detailed radiological studies, the patient, known for Crohn’s disease, was scheduled for laparoscopy in the suspicion of small bowel stricture. A localised dilatation of the ileum was found intraoperatively and subsequently resected. A systematic review of this rare pathology in adults is carried out. ILDI should be part of the differential diagnosis in patients with unexplained abdominal pain or gastrointestinal bleeding in the presence of segmental dilatation of the intestine. Surgical resection is the treatment of choice.

Background

Idiopathic localised dilatation of the intestine (ILDI) is rare in adults, and only few cases have been reported in the literature.^1–7 ILDI is defined as a segmental dilatation of a well-defined segment of intestine with abrupt transition to a normal bowel proximally and distally, without mechanical blockage or deficient neuromuscular architecture.⁸ This pathology has also been named segmental dilatation of the ileum,⁹ and ileal dysgenesis,¹⁰ segmental mega-ileum.³ Hereby the clinical case of 32-year-old women is presented, and the literature systematically reviewed.

Case presentation

A 32-year-old woman presented at the emergency department with abdominal pain of varying localisation for 2 weeks as well as constipation. Nausea or vomiting was denied. The physical examination revealed tenderness in the lower abdomen. However, there were no clinical signs of peritonitis. Blood tests were inconspicuous without laboratory signs of inflammation.

The patient was known for Crohn’s disease for 3 years. The disease course had been mild without the need for maintenance therapy. A year ago, a sleeve gastrectomy had been performed for obesity (WHO grade III, body mass index 43 kg/m²). No signs of adhesions or bands were observed thereafter. After this surgery, a significant excessive weight loss was achieved. At presentation, the body mass index was 25 kg/m². No abdominal symptoms were reported during childhood.

Investigations

Abdominal CT demonstrated a severe dilatation of a small bowel loop in the mid-abdomen with small bowel faeces sign (figure 1A). Additionally, a magnetic resonance (MR) enteroclysis was performed, which showed a suspected long stenosis of 1 cm length in the proximal ileum with massive dilatation of the preceding ileum up to 9 cm in diameter. In contrast to the CT, in the MR, the dilated bowel segment was located in the left upper quadrant, suggesting a mobile bowel segment (figure 1B). A segmental small bowel stenosis due to Crohn’s disease was suspected, and a treatment with intravenous methylprednisolone 125 mg/day was started. Upper endoscopy was normal, coloscopy showed a mild unspecific erosive inflammation at the ileo-caecal valve and the terminal ileum, with histologically also mild acute inflammation, compatible with Crohn’s disease.

Figure 1.

(A) CT and (B) magnetic resonance enteroclysis showing a saccular lesion (white arrowheads) with proximally and distally abrupt transition (yellow arrows).

Treatment

As pain did not respond to conservative treatment within 1 week, surgical exploration was decided. A laparoscopy was performed. However, no obstruction of the small bowel was detected. The small intestine was revised, and in the proximal ileum, at approximately 200 cm from the ileo-caecal junction, a massive dilatation of a short ileal segment with normal calibre of the adjacent proximal and distal small bowel was found. The antimesenteric border of the dilated bowel segment was altered by inflammation. A segmental resection of the dilated ileum was performed with a stapled side-to-side anastomosis. The dilated bowel segment was 9 cm long and 10 cm wide (figure 2).

Figure 2.

Resected specimen with inflammatory alteration of the serosa due to ulceration (white arrow).

The histopathological examination showed macroscopically a dilatated ileal segment with a 1.5×1 cm ulcer at the antimesenteric border and normal valvulae conniventes.

Microscopically, the small bowel wall was normally structured without metaplasia or signs of ectopic gastric mucosa (figure 3). No signs of obstruction were identified. The muscular layers and myenteric plexus were preserved. A Meckel’s diverticulum and a manifestation of Crohn’s disease were excluded. The cause of ulceration remained unclear (figure 4).

Figure 3.

Histological examination (H&E stain, original magnification ×20). Superficial ulceration (box) sharply demarcated from adjacent normal ileal mucosa with fibrin/granulocytes inflammatory infiltration (blue arrow) and lymphoplasmacytic inflammatory infiltrate (asterisks).

Figure 4.

Macroscopical aspect of the specimens mucosa with ulceration.

Outcome and follow-up

Postoperative recovery was uneventful with resolution of abdominal pain.

In this report, an incomplete small bowel obstruction (SBO) due to ILDI in a young woman is reported. It has to be assumed that the dilated bowel segment acted as a fulcrum point of repeated twisting of the preceding small bowel, thus leading to intermittent SBO.

Discussion

A systematic literature search with the mesh terms ‘ileal/gastrointestinal/small bowel segmental dilatation’ or ‘idiopathic localised dilatation of the ileum/gastrointestinal tract/small bowel’ in MEDLINE, performed on 12 August 2018, yielded a total of 158 articles. Eighty-seven articles were excluded, among these, 76 did not report on segmental small bowel dilatation, nine articles were not in English, and two articles reported on animals. Of the remaining publications, 64 articles reported paediatric cases, and only seven articles on ILDI in adults (table 1). Since the first description by Marshall et al,¹¹ 18 cases of ILDI have been described in adults. Of those, 7 (39%) were female, and 11 (61%) were male. Patient age ranged from 25 to 72 years, with a median of 48 years. ILDI is more frequently localised in ileum and colon, rarely in the jejunum and duodenum.^{12 13}

Table 1.

Sex, mean age, proportion of segmental resection, length and width of idiopathic localised dilatation of the small bowel in the literature

	Patients (n)	Women/men	Mean age	Segmental resection (%)	Length (cm)	Width (cm)
Javors et al 2	9	5–4	52 (35–71)	78	13.7 (6.3–20.7)	6.5 (3.5–12.8)
Leinster and Hughes4	2	0–2	38 (25–51)	100	11 (10–12)	6.0
Usselman et al 6	3	2–1	45 (31–58)	33	10.0	–
Simpson et al 5	1	0–1	31	100	8.0	5.0
Kim et al 3	1	0–1	69	100	–	9.5
Kim 2012	1	0–1	72	100%	10	8
Yang et al 7	1	0–1	62	–	10	7

More often ILDI has been described in the neonatal and paediatric population indicating that ILDI is a congenital anomaly.¹⁴

This argument is supported by the described correlation of ILDI together with other congenital abnormalities.¹³ An obstruction of a bowel loop during the intrauterine period has been suggested as the cause of ILDI. Such an obstruction may occur intraabdominally or due to external structures or also during mid-gut herniation in the vitellin duct. The intestinal loop is constricted in its proximal and distal part, causing segmental dilatation.^{3 14} Usselman et al have proposed idiopathic neuromuscular dysfunction in the isolated intestinal loop as the reason of dilatation.⁵ However, although Usselman describes an aperistaltic segment in Barium enema in 2 out of three patients, none of them had surgical resection, and consequently, no pathological examination. The third patient had surgical resection, and the pathological examination did not reveal any neuromuscular dysfunction. This parallels the finding in our case where no neuromuscular dysfunction was detected on pathological examination.

Of the 18 adult cases described in the literature, 50% (9 patients) had abdominal pain or signs of obstruction, while 72% (13 patients) presented with gastrointestinal bleeding with or without anaemia. This latter presentation being presumably the consequence of an underlying ulcer in the dilated segment.^{1 3} Ulceration itself seems to be caused by chronic stasis of intestinal content⁵ or due to mechanical ischaemia during malrotation or intussusception.⁴

Radiological diagnosis was mostly done through small bowel series (89%). Three patients (17%) had abdominal CT, and one had additionally an abdominal sonography. Although detectable in those radiological studies due to its rarity, ILDI remains difficult to diagnose before surgery. It may mimic other pathologies such as aneurysmal dilatation in lymphoma, intestinal obstruction, and Meckel’s diverticulum.^{1 4} As there is no specific diagnosis to confirm ILDI, it remains a diagnosis of exclusion. In our case, as the patient was known for Crohn’s disease, the marked segmental bowel dilatation was misinterpreted as small bowel strictures even though CT and MR enteroclysis were performed.

As in our case in the literature, 72% of adult patients underwent segmental resection (table 1). The remaining 28% of patients were asymptomatic and incidentally diagnosed. Surgical treatment was not performed in those cases.

Pathological examination revealed ulceration and two (15%) metaplasia (gastric mucosa) in all cases. Normal structured bowel wall with all layers present, and no further pathologies were detected in all cases.

A small bowel giant diverticula was excluded, as this latter lack a true muscular wall and is usually located on the mesenteric border.¹⁵ The absence of mucosal lining within the intestinal lumen excluded an enteric duplication cyst.¹⁶

Learning points.

• Idiopathic localised dilatation of the intestine (ILDI) could be the cause of unexplained abdominal pain or gastrointestinal bleeding in adult patients.

• Although ILDI is very rare in adults, it should be part of the differential diagnosis in the presence of segmental saccular dilatation of the intestine in radiological examination.

• Surgical resection is the treatment of choice in symptomatic patients.