Giant rectal vascular malformation: a rare differential diagnosis in rectal bleeding

Abstract

Investigations in a woman with prolonged symptoms of laxative-resistant constipation and recurrent rectal bleeding revealed a giant rectal vascular malformation. Colonoscopy and MRI were performed to rule out malignancy and determine differential diagnoses. Repeated tests were necessary due to inconclusive results. After a definite diagnosis, image-guided, transcutaneously administered sclerotherapy was used. The intervention and postoperative course were uneventful. A minimally invasive procedure relieved symptoms and improved quality of life.

Background

Lower gastrointestinal bleeding is a common problem seen in the emergency room and electively, depending on severity. Many causes of bleeding, especially in young patients, are benign and originate from anal manifestations such as fissures or haemorrhoids. The complete clinical presentation must be considered to identify patients requiring investigation beyond proctoscopy, such as those without anal pathology or anal pathology with a possible second, unrelated disease.

Rectal vascular malformations are rare. A definite diagnosis can take a long time, burdening the patient and the health system.¹ Surgical resection has been the standard treatment historically. Recent case reports address the option of interventional therapy to treat rectal vascular malformations.^2–4 We present a case of using sclerotherapy to treat a giant rectal vascular malformation.

Case presentation

A fit woman in her late 30s, with essential hypertension, multicystic, dysplastic kidney disease and a family history negative for colorectal cancer and vascular malformations, was referred to the department of colorectal surgery with laxative resistant constipation, intermittent rectal pain and recurrent, bright red rectal bleeding ongoing for months. She had no surgical history and had never had a colonoscopy. CT, MRI and colonoscopy with biopsies performed prior to referral demonstrated circumferential bowel wall thickening extending from the rectum to the distal sigmoid colon, suggesting a vascular malformation. The results of the biopsies were characteristic of a tubular adenoma. The anal and digital rectal examinations were normal except for a solitary skin tag. General examination and vital parameters were unremarkable. Haemoglobin was decreased to 107 g/L.

Investigations

Before referral, a CT abdomen/pelvis and an MRI pelvis were performed. CT revealed severe thickening of the rectosigmoid colon wall and adjacent soft tissue and infiltrative nodular changes in the mesorectal fat with multiple scattered calcifications within the rectal wall (figure 1).

Figure 1.

CT showing severe thickening of the rectosigmoid colon wall and mesorectum (red brackets) with multiple, adjacent calcifications (red arrows).

The subsequent MRI confirmed the extent of the mass with a craniocaudal length of 16 cm, starting 1.2 cm above the anal verge, infiltrating the mesorectal fat and fascia and involving the upper anal sphincter complex and intersphincteric spaces, including the perineal tissue. Multiple calcifications corresponded to phleboliths (figure 2). Serpiginous vessels on MRI were seen in the rectal wall. This imaging was suspicious for a giant vascular malformation.

Figure 2.

MRI showing findings consistent with giant rectal vascular malformation. (red brackets: thickened rectal wall and mesorectal tissue; red arrows: serpiginous vessels).

On initial presentation to our institution’s department of colorectal surgery, an anoscopy revealed three enlarged haemorrhoidal columns and friable rectal mucosa. Flexible sigmoidoscopy showed a large rectal mass involving the rectum, reaching from proximal to the anal verge to the sigmoid colon, consistent with the previous imaging (figure 3). New biopsies were taken in our institution, which excluded a tubular adenoma and were conclusive for a benign vascular lesion.

Figure 3.

Colonoscopy showing the extensive rectal mass and friable mucosa.

Differential diagnosis

Rectal bleeding can be a sentinel symptom for multiple conditions, as outlined in table 1. In acute lower gastrointestinal haemorrhage, it is crucial to evaluate the severity of the bleeding. If haemodynamic instability is present, resuscitation and exclusion of an upper gastrointestinal bleeding source follow. CT angiography is recommended in patients who are haemodynamically unstable or have a shock index (heart rate/systolic blood pressure) >1 after primary resuscitation or have suspected active bleeding. CT angiography has a reported specificity of 95%–100% and sensitivity of 79%–95%. A bleeding rate of 0.3–0.5 mL/hour has to be present to allow localisation.⁵ Catheter angiography with possible embolisation is recommended as soon as possible (ideally 60 min) after an identified bleeding on CT angiography to maximally increase the chances of success.⁶ The European Society of Gastroenterology recommends the reservation of transcatheter arterial embolisation for cases with localised active bleeding on CT angiography or ongoing bleeding not treatable by endoscopic interventions. For successful localisation, an active bleeding of a rate of 0.5–1 mL/hour is needed.⁷ Upper gastrointestinal sources are more likely to bleed severely, so an upper gastrointestinal endoscopy should precede CT angiography if the patient stabilises after primary resuscitation or follow immediately if no source is identified in unstable patients.^{6 7} If the patient is haemodynamically stable, the Oakland score provides help in determining how timely diagnostics have to be performed and if outpatient management is feasible.⁸ Figure 4 outlines a possible algorithm for acute lower gastrointestinal bleeding.

Table 1.

Causes of acute rectal bleeding

Cause	Incidence
Diverticulosis	5%–42%
Ischaemia	6%–18%
Anorectal	6%–16%
Haemorrhoids Anal fissures Rectal ulcers
Small bowel or upper gastrointestinal bleed	3%–13%
Neoplasia	3%–11%
Cancer Polyps
Inflammatory bowel disease	2%–4%
Radiation colitis	1%–3%
Vascular malformations	0%–3%
Other colitis	3%–29%
Infectious Ischaemic Antibiotic
Unknown causes	6%–23%

Figure 4.

Algorithm acute rectal bleeding. CTA, CT angiography; CTE, CT enterography; GI, gastrointestinal; HR, heart rate; MRE, MR enterography; SBP, systolic blood pressure; SI, Shock Index.

Superficial conditions, such as anal fissures, internal haemorrhoids and ulcerated external haemorrhoids, can mostly be excluded by a physical examination and anoscopy. The history of rectal bleeding, implies a colonoscopy to rule out inflammatory bowel disease, diverticular bleeding, neoplasia or colitis. Colonoscopy has diagnostic and therapeutic value as applying different treatment options, taking biopsies or tattooing suspicious lesions is possible. Furthermore, colonoscopy is safe and is diagnostic in 42%–90% of patients.⁶ If investigations show non-conclusive results, repeated investigations or imaging might be necessary before deciding on a definite therapy. Gastrointestinal vascular anomalies are most often diagnosed through endoscopic intervention and imaging. Associated comorbidities or a family history need to be considered, as vascular anomalies can be hereditary or part of a syndrome. The International Society for the Study of Vascular Anomalies provides the most recent classification for conditions subsumed under vascular anomalies. The provided table 2 outlines the main classes and common entities.⁹ In the presented case, a definite diagnosis was established by MRI findings, colonoscopy and biopsies.

Table 2.

Exemplary vascular anomalies causing rectal

Vascular anomalies
Vascular tumours/angiomas	Vascular malformations
Bengin	Vascular malformations associated with syndromes	Vascular malformations (capillary, venous, lymphatic, arteriovenous, combined)
Haemangioma	Klippel-Trénaunay-Weber syndrome	Angiodysplasia
Pyogenic granulomas	Ehlers-Danlos syndrome	Gastric Antral Vascular Ectasia
Borderline	Sturge-Weber syndrome	Dieulafoy’s lesion
Various haemangioendothelioma	Blue rubber bleb nevus syndrome	Portal hypertensive gastropathy
Kaposi sarcoma	Hereditary haemorrhagic telangiectasia	Radiation-induced vascular ectasias
Malignant	Maffucci syndrome
Angiosarcoma
Hepatic angioasarcoma
Epitheloid haemangioendothelioma

Treatment

On exclusion of a malignant process, treatment options were outlined to the patient. Embolisation or sclerotherapy was deemed a good balance of invasiveness versus the risk of recurrence. In case of recurrence or treatment failure, surgical therapy would have consisted of an abdominoperineal resection with end colostomy due to the involvement of the sphincter complex.

One month later, the patient underwent uncomplicated sclerotherapy under general anaesthesia performed by our interventional radiology colleagues. Image-guided access was achieved via a percutaneous, trans gluteal puncture of the perirectal malformation (figure 5). The vascular malformation was pictured through a venogram. As a sclerosing agent, 28 units of bleomycin and 5 mL of albumin 25% were administered. Figure 6 shows the main arterial vessels involved in the malformation. The postoperative course was uneventful, and the patient was discharged the same day.

Figure 5.

Sagittal plane of a dissected rectum from left; Vessels supplying the rectal vascular malformation are superior, middle and inferior rectal artery Visible Body Suite (Version 4.31), [Windows 10 Enterprise]. (2023). Retrieved May 29, 2023 from www.visiblebody.com

Figure 6.

Coronal plane of the gastrointestinal tract. Predilection sites of vascular malformations listed in table 2. Visible Body Suite (V.4.31), (Windows 10 Enterprise). (2023). Retrieved 29 May 2023 from www.visiblebody.com.

Outcome and follow-up

The patient was advised against rigorous physical activity for 3 weeks, after which reintroduction was uneventful. The first follow-up was 6 weeks postoperatively. Rectal bleeding and constipation decreased significantly, pain was relieved and sleeping rhythm improved. A dietitian was consulted to work with the patient for dietary advice.

Another follow-up was done 1-year postoperatively. The patient experienced minimal bleeding now and then and a single, tolerable pain episode in 12 months.

Follow-up imaging and colonoscopy were considered unnecessary during the first year if symptoms did not restart or worsen. An MRI pelvis was planned for 18 months postintervention.

Discussion

Rectal vascular malformations are rare entities.¹ Analysis of the literature is aggravated by non-uniform nomenclature and frequent combining of the two different entities of haemangioma and vascular malformation. The most recent classification emphasises this distinction.⁹ Table 1 lists the more common vascular anomalies to their classes: vascular tumours, vascular malformations associated with syndromes, and sporadic or acquired vascular malformations. Figure 7 shows the predilection sites of listed vascular anomalies. The term haemangiomas is best reserved for anomalies with solid tumourous character, a high endothelial cell turnover, appear after birth and present mostly a self-limiting course. Haemangiomas are benign vascular tumours, to which more commonly known entities, such as congenital haemangioma, infantile haemangioma and pyogenic granuloma known as lobular capillary haemangioma, are counted.

Figure 7.

Algorithm acute rectal bleeding. CTA, computed tomography angiography; CTE, CT enterography, GI, gastrointestinal; HR, heart rate; MRE, magnetic resonance enterography; SBP, systolic blood pressure; SI, shock index. Flowchart drawn by Schabl, L.

Vascular malformations have a normal endothelial cell turnover, are mostly present at birth and seem to grow in size over time due to progressive vessel dilatation.^{1 10} Angiodysplasias are the most common gastrointestinal vascular anomaly and are ectatic, dilated vessels with a thinly lined endothelium. While they can be found in the entire gastrointestinal tract, the predilection site is the cecum and the small bowel. Up to 60% of patients are reported to have angiodysplasias on multiple sites.¹⁰ Symptoms vary from asymptomatic, melena and haematochezia to occult bleeding. While endoscopy and video capsule endoscopy are the mainstays of diagnostics, treatment remains to be elucidated. Incidental findings can be left untouched. Bleeding angiodysplasias are treated endoscopically with coagulation, clips or radiofrequency ablation. Rebleeding might occur in up to 45%.¹¹ A recent meta-analysis showed a decreased recurrence rate when pharmacological treatment such as thalidomide, antiangiogenics, somatostatin analogues or hormonal therapy was applied.¹¹ Major haemorrhage, most often at the gastro-oesophageal junction, may occur in the presence of Dieulafoy’s lesions. They are rarely located in the small bowel, colon or rectum. Dieulafoy’s lesions’ capacity to cause massive haemorrhage is one reason massive haematochezia should lead to an oesophagogastroduodenoscopy before a colonoscopy.¹⁰ Treatment is primarily endoscopic, whereas a meta-analysis has shown a similar efficacy of endoscopic band ligation and haemoclip placement.¹²

Delay to definite diagnosis is reported from 2 months to 70 years and can burden the patient and health system with recurrent symptoms, admissions, diagnostics and treatments.^{1 13} Symptoms most often reported with rectal vascular malformations are recurrent rectal bleeding, anaemia, and, more rarely, a change in bowel habits or pain.¹ History and physical are essential to evaluate differential diagnosis before proceeding with investigations.

A colonoscopy is often the first examination in patients with recurrent rectal bleeding. Localising the source, distinguishing between active or occult bleeding, and ruling out an intraluminal pathology are important for further decision-making.³ In cases where there is a question of malignancy on endoscopic evaluation, biopsies are encouraged. However, the need for biopsies should be outweighed by the risk of bleeding if suspicion of vascular malformation exists.¹ In the presented case, a repeat colonoscopy with biopsies was necessary because biopsies, done in an external institution, did not show results consistent with the patient’s imaging. A complete colonoscopy is advised in all patients presenting with vascular malformation, even in the rectosigmoid region, because cases of multifocal involvement have been reported.³

Rectosigmoid vascular malformations have been described most commonly in MRI studies. Their characteristics typically include circumferential thickening of the wall, a nodular and uniform pattern, and a proximal extension up to 30 cm. Scattered phleboliths in the abnormal, heterogeneous perirectal fat and perineal involvement are present. The rectosigmoid thickening is homogeneous and hypointense on T1-weighted and hyperintense on T2-weighted images.¹⁴

Based on 18 patients with rectosigmoid vascular malformations, Brill et al propose an algorithm for rectosigmoid vascular malformations.² If imaging features such as minor distention of the bowel wall, punctual bleeding, monosegmental distribution, and involvement of the anal sphincter are present, sclerotherapy should be the first-line treatment. Percutaneous or endoscopic access is possible depending on the malformation’s localisation. In primary recurrence, the next step would be transvenous or transhepatic sclerotherapy. After the failure of second-line therapy, resection should be considered. Asymptomatic patients can be treated on a watch-and-wait basis.²

Brill et al also presented a series of patients, where seven were treated with sclerotherapy (six endoscopically assisted, one direct percutaneous puncture). Rebleeding occurred in one out of seven, and endoscopically assisted sclerotherapy was reattempted. Hence, there was only one recurrence during a follow-up period of 2 years.²

Multiple case reports have been published applying transvenous embolisation as a first-line therapy.⁴ The approaches chosen were either transvenous or transhepatic. The combined recurrence rate in 10 Japanese case reports reporting treatment of intestinal vascular malformations with transvenous embolisation was 33%.⁴ Jubashi et al applied a simultaneous transarterial and–venous approach, hypothesising that cessation of the arterial inflow during embolisation would completely eradicate the vascular nidus while decreasing the risk of unintentional embolisation of other organs.⁴

Surgery is advised in extended disease, recurrence or significant haemorrhage.^{2 3} Procedures performed depend on the localisation of the malformation and are tailored to the disease and patient. Case reports describe successful treatment with transanal total mesorectal excision with a coloanal anastomosis and protective loop ileostomy, laparoscopic-assisted abdominoperineal resection and laparoscopic-assisted anal pull-through resection with coloanal anastomosis.¹⁵ Open and laparoscopic approaches are described.¹⁶ It is important to excise the malformation with unaffected margins; otherwise, recurrence can occur.² We think that due to the invasive nature of the procedure, intraoperative risk and postoperative complications, surgical intervention should not be the first line of therapy and should be restricted.

Patient’s perspective.

My back started hurting rbadly, and then my stomach hurt so badly I could not do anything. I went to my general practitioner, who sent me straight for testing (blood work) and a CT scan of my abdomen. When the results came back, she referred me to a gastroenterologist. The gastroenterologist did a stool sample and a colonoscopy. He immediately saw me with the results and said that I had a mass that was too big and that he couldn’t touch it. He referred me straight to another specialist. With the specialist, I had a sigmoidoscopy and MRI. He saw me with the results and wanted to do surgery, cut my mass out of my intestines, put a colostomy bag on or send me to another specialist at the Cleveland Clinic. With the specialist at the Cleveland Clinic, I had a sigmoidoscopy done and talked with another specialist about the best treatment besides surgery and a colostomy bag. The specialist at the Cleveland Clinic said it was very big, very rare, and not in a spot where they normally grow and that they haven’t even really seen anything like this before. The mass reached up 16 cm from the anal verge. It was large enough to displace my organs.

After talking with the specialist about the issue, I realised that I had had many years of signs and symptoms that I had not realised were a part of the mass growing inside of me. Signs and symptoms were a hard time pooping, going to the bathroom a lot due to not emptying all the stool, Lots of blood in the stool, lots of belly pain, lots of bloating, lots of back pain, I was very anaemic (feeling cold), not eating right, on stool softeners a lot and very tired because I could not sleep well due to my signs and symptoms. At the time of the diagnosis, I was pulling and pushing a lot of weight around due to my job. After surgery, the surgeon had me off for about one week for my body to start recovery. When I returned, I was put on a no more than 10–20 pounds lifting/pulling weight limit so it would not mess up my healing process. The surgeon told me that any strain or stress on my abdomen would aggravate my healing process. He also said that any stress, pregnancy, accidents or anything stressful or major to my abdomen could cause the mass to grow and cause problems.

Since the healing process, I have experienced minimal bleeding every now and then and one episode of pain, which was tolerable. Symptoms occur mostly when I’m stressed or do not eat right.

Learning points.

• Meticulous and complete investigations are necessary for patients with unclear and persistent rectal bleeding to avoid delay in diagnosing pathology, including rectal vascular malformation.

• Symptoms of rectal vascular malformations overlap with those of rectal cancer.

• Algorithms are helpful in clinical practice, feasible and might allow uniform studies with more patients.

• Interventional radiology-guided sclerotherapy with bleomycin and albumin was successfully used in our case.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).