Primary Adenocarcinoma at Ileostomy—A Rare Late Complication: Three Cases and Literature Review

The first case is a 39-year-old female with a body mass index (BMI) of 49 kg/m² and a history of FAP treated with a total proctocolectomy with ileostomy in 1998. In 2003, she required laparotomy for small bowel obstruction secondary to adhesions. At that time, the mesentery was noted to be thickened in several areas, with whitish fibrous bands, suggestive of early desmoid tumors. The patient was placed on Celebrex. The patient developed a parastomal hernia with minimal symptoms for which she declined surgery. She continued her upper gastrointestinal endoscopic surveillance as per the established guidelines. Gastric fundic polyps and diminutive duodenal adenomatous polyps were removed.

The patient had yearly follow-up appointments that were unremarkable. She presented in December 2015 with a 2-month history of a “lump” next to her ileostomy with difficulty keeping the appliance in place, a foul odor, and bloody ileostomy output (Figs. 1 and 2). A biopsy was done in the office confirming a well-differentiated adenocarcinoma. A computed tomography (CT) scan demonstrated a large parastomal hernia and an ill-defined oblong infiltrating mass in the small bowel mesentery measuring 11 cm in length and 3 cm in diameter, consistent with a desmoid tumor.

Ileoscopy evaluated the distal 40 cm of the ileum without abnormality. Baseline CEA level was 5.2 ng/mL.

Surgical management consisted of a partial small bowel resection including the adenocarcinoma at the ileostomy site and repair of parastomal hernia with excision of the hernia sac and primary closure of the fascia. Plastic surgery was on standby in the event that the patient would require resiting of the ileostomy along with a complex abdominal wall closure. A closed surgical drain was used.

The patient recovered well and was discharged home on postoperative day 4 with the drain in place. This drain was removed on postoperative day 13. She presented 5 days later with a subcutaneous abscess adjacent to the ileostomy. This was managed with intravenous antibiotics and percutaneous drainage with resolution.

This case is an 86-year-old male with a history of multiple medical problems. Initially, he had a right colectomy for carcinoid tumor in 2001; he recovered well from the first surgery. In 2005, he was diagnosed with descending colon cancer; he had completion colectomy and end ileostomy. In 2013, he presented with abnormal growth at the mucocutaneous junction and ileostomy bleeding. Biopsy of the growth showed mucinous adenocarcinoma for which he underwent a resection with relocation of ileostomy.

This case is a 64-year-old female with a history of low rectal cancer and right colon cancer. She underwent total proctocolectomy and end ileostomy. Sixteen months later, she presented with ileostomy irritation, and a biopsy confirmed adenocarcinoma. She was treated with wide excision and ileostomy relocation. The follow-up PET scan was negative.

Since the introduction of permanent ileostomy as a surgical treatment option, a number of complications have been observed including skin excoriations, retraction or prolapse of the stoma, stenosis, intestinal obstruction, abscess, fistula, ileitis, and inflammatory polyps.⁸  Malignancy at the ileostomy site is also a known but rare complication.^1,3,9,11 

The incidence of small bowel malignancy in the general population is 0.7 per 100,000.¹  The ileum is most frequently involved (49%) followed by the jejunum (29%) and duodenum (22%). In contrast, adenocarcinoma of the small bowel is least commonly found in the ileum (22%), followed by the jejunum (38%) and duodenum (40%). Suarez et al estimated the incidence of ileostomy carcinomas in Britain to be 2–4 per 1000 ileostomies.^5,7 

Primary adenocarcinoma at the ileostomy site aftertotal proctocolectomy for FAP is even more unusual, with a very low number of published cases.⁶ 

Our first case report illustrates the complicated management of a patient with 2 rare manifestations of FAP. Carcinomas of the upper gastrointestinal tract in FAP are rare.¹  Furthermore, the operative decision making was complicated by the presence of high BMI and a large parastomal hernia. Fortunately, there was a large amount of small bowel and mesentery in the parastomal hernia, and this allowed for an adequate oncologic resection without a need for laparotomy. Primary closure of the fascia was feasible, obviating the need for a laparotomy and additional intra-abdominal surgical trauma that may have accelerated the growth of the desmoid. A more extensive repair of the hernia would have likely required a complex abdominal wall closure. The tradeoff was accepting a higher risk of recurrence of the parastomal hernia, but we considered this to be preferable than the potential progression of the desmoid.

Our search showed that the most common malignancy at ileostomy site is adenocarcinoma.¹ 

We found 57 cases of adenocarcinoma reported in the literature¹ : 42 adenocarcinoma after TPC for UC and 15 adenocarcinoma after TPC for FAP,⁴  6 cases were SCC, and 1 case was lymphoma.¹ 

Our second and third reported cases has no history of UC or FAP.

Symptoms are bleeding, difficulty fitting the stoma appliance, and bowel obstruction.^1,4 

The differential diagnosis is Crohn's disease, ileitis, or backwash ileitis at the stoma, pseudoepitheliomatous hyperplasia, extensive pseudopolyposis or granulationtissue, pyoderma gangrenosum, and squamous cell carcinoma.¹ 

On examination, a polypoidal friable bleeding mass or ulcerative lesion at the mucocutaneous junction of the ileostomy.^1,4 

The etiology of ileostomy adenocarcinoma is unclear.^1,9  Patients with a long-standing ileostomy following TPC for UC and FAP appear to be at a greater risk of developing adenocarcinoma at the ileostomy site than patients with an end ileostomy because of other non-UC and/or no FAP disease.⁴ 

Possible etiologies are mentioned in the literature: chronic irritation may predispose the ileal mucosa to colonic metaplasia, dysplasia, and frank malignant change,^1,2,4  and the disease process that precipitated the formation of ileostomy may play a causative role in carcinoma formation.⁴  Changes in the bacterial flora also have been reported to be associated with cancer occurrence, as well as an association between ileitis or backwash ileitis and mucosal dysplasia and cancer transformation.^1,9 

Malignant transformation in a preexisting benign adenoma.³  Some authors have hypothesized that ileostomies created more than 20 years ago are at an increased risk. The potential for this malignant transformation should serve as a reminder to monitor the ileostomy in these patients and biopsy any mucosal abnormalities.⁴ 

Two of our reported cases had no UC or FAP, which suggests that ileostomy adenocarcinoma development could occur regardless of the primary etiology that led to creation of the permanent ileostomy.

The treatment remains surgical. An en bloc wide local excision of the ileostomy with the adjacent anterior abdominal wall with or without transposition of the stoma to a new site has been shown to provide the best prognosis for an adenocarcinoma arising from an ileostomy,^1,2,4,10  with an 85% survival rate.^1,2 

Lymph node involvement is reported in 19% of cases, and in this group of patients, adjuvant therapy may have additional benefit.¹ 

Table 1 summarizes all the reported ileostomy adenocarcinoma cases; the last 3 cases in the table are the cases reported in this paper.

Although ileostomy adenocarcinoma is rare, its incidence seems to be on the rise with increasing number of case reports in the last few years.¹ 

The patient, ostomy nurse, and surgeon should be aware of this late complication, and an annual examination for ileostomy is advised.^1,9  Any abnormal growth and/or nonhealing wound should be considered for biopsy. Treatment is wide excision with lymph node sampling, and overall prognosis seems to be good.