Intestinal obstruction caused by low-grade appendiceal mucinous neoplasm: A case report and review of the literature

Complete small intestinal obstruction due to band formation in low-grade appendiceal mucinous neoplasm: A rare case report and literature review

INTRODUCTION

Intestinal obstruction due to external compression is a rare condition, and those caused by appendiceal neoplasms like low-grade appendiceal mucinous neoplasms are extremely rare.

PRESENTATION OF CASE

A 67-year-old post-menopausal female, with no history of prior abdominal surgery, presented to the emergency room with constipation for 2 days, and peri-umbilical pain and non-projectile bilious vomiting for 19 h. There was mild abdominal distension and diffuse tenderness. After ultrasonography and Computed Tomography (CT) of the abdomen and pelvis, a provisional diagnosis of complete small bowel obstruction secondary to perforated mucinous neoplasm of the appendix was made. An emergency exploratory laparotomy was performed followed by ileo-cecal resection and ileocolic anastomosis. Intraoperative findings revealed bands extending from the appendix to the ileum forming a closed loop with gangrenous spots in the distal ileum and ascitic fluid with mucin. Later, histopathological examination findings were consistent with low-grade appendiceal mucinous neoplasm (LAMN).

DISCUSSION

We reviewed three cases of intestinal obstruction, caused by compression from a LAMN, including the presented case. Preoperative diagnosis of the cause of small intestinal obstruction on CT is sometimes challenging. Hence, in patients with intestinal obstruction with a transition point in the right lower quadrant of the abdomen on CT, a high index of suspicion for an appendiceal etiology is required.

CONCLUSION

LAMN with an associated band should be considered as one of the differential diagnoses in the patient presenting with symptoms of complete small intestinal obstruction without prior abdominal surgery.

Blind loop mucocele of a side-to-end colorectal anastomosis as a rare cause of large bowel obstruction

Large bowel obstruction (LBO) after colorectal surgery draws wide differentials. To our knowledge, LBO due to blind colonic limb mucocele of a side-to-end colorectal anastomosis has not yet been described. We report a man in his late 50s presenting with pain, abdominal distension and constipation. He had extensive surgical history; notably, a side-to-end colorectal anastomosis was fashioned following Hartmann-type colostomy reversal. CT and MRI suggested a mucus-filled short blind colonic segment compressing the anastomotic site and causing LBO. Flexible sigmoidoscopy under general anaesthesia showed external rectal compression and lumen narrowing. Transrectal needle aspiration of the blind segment yielded 145 mL of mucoid fluid. The patient's symptoms improved and he was discharged with outpatient Gastrografin enema and flexible sigmoidoscopy which confirmed successful blind segment emptying. This case highlights that blind colonic loop mucoceles in colorectal anastomosis can rarely cause obstruction, and endoscopic management is feasible when accurate diagnosis is confirmed on imaging.

Appendiceal Mucinous Tumor Presenting as Recurrent Bowel Obstruction

Appendiceal mucinous tumors are rare, with variable malignant potential, and they are usually found incidentally. Clinical symptoms are nonspecific. Rarely, appendiceal mucinous neoplasm causes bowel obstruction and makes diagnosis more difficult. We present a case of an 84-year-old female who came to our emergency department having had abdominal fullness and constipation for 5 days. Ileus, due to an affected adhesion band, was diagnosed initially, and symptoms improved gradually under conservative treatment. However, 3 months later she presented to the emergency department again with abdominal pain and distension; small bowel obstruction due to adhesion was again diagnosed. Recurrent bowel obstruction prompted emergent surgery. Operative findings showed a whitish appendiceal tumor adhering to and directly invading the adjacent ileum, with a segment of herniated small bowel wedged in between, causing the obstruction. Upon reviewing the initial computed tomography scan, the dilated tubular structure of appendiceal tumor was misrecognized as small bowel loop; there was no surrounding inflammatory sign, leading to diagnosis difficulty. Instead of a common cause of bowel obstruction, such as adhesion band, this case revealed bowel obstruction can be caused by the direct invasion of an appendiceal tumor. Awareness of this condition with careful image evaluation of small bowel obstruction is essential for diagnosis.

Spectrum of computed tomography manifestations of appendiceal neoplasms: acute appendicitis and beyond

Appendiceal neoplasms are rare and often only discovered incidentally during surgery performed for acute appendicitis. Computed tomography (CT) has been demonstrated to be a reliable technique for accurately establishing the preoperative diagnosis of appendiceal neoplasms that manifest as acute appendicitis through the presence of certain imaging findings. Other manifestations of appendiceal neoplasms include appendiceal mass, mucocoele, localised abscess formation, ileus, increasing abdominal girth from pseudomyxoma peritonei, and intussusception. This pictorial essay illustrates varied CT findings of neoplasms of the appendix, with emphasis on the more commonly encountered manifestations of these tumours.

A Case of Strangulation Ileus Due to a Low-Grade Appendiceal Mucinous Neoplasm

BACKGROUND Strangulation ileus is caused by external obstruction to the small bowel, which results in ischemia and loss of bowel peristalsis. Low-grade appendiceal mucinous neoplasm (LAMN) is a low-grade adenocarcinoma that arises in the appendix. LAMN is usually asymptomatic but can present with appendiceal rupture and pseudomyxoma peritonei (PMP). This report is of a rare presentation of LAMN with strangulation ileus in a 92-year-old man. CASE REPORT A 92-year-old man was admitted to the emergency room with sudden onset of lower abdominal pain and abdominal distension. Laboratory investigations showed a leukocytosis with a white blood cell (WBC) count of 14.6×10³/μL with 85.5% neutrophils, blood urea nitrogen (BUN) of 26.6 mg/dL, and serum creatinine of 2.6 mg/dL, consistent with acute renal failure. Arterial blood gas analysis showed lactic acidosis (pH of 7.11) with a base excess of -20.8 mmol/L and lactate of 13.7 mmol/L. Abdominal computed tomography (CT) showed ascites and a dilated obstructed closed loop of the distal ileum associated with an external mass (3.9×2.8 cm). An initial diagnosis was of strangulation ileus due to Meckel's diverticulum. Emergency ileocecal resection was performed. Histopathology showed a low-grade mucinous tumor arising from the mucosa of the appendix, consistent with LAMN. At a 13-month follow-up, the patient was well with no tumor recurrence. CONCLUSIONS This report is of a rare case of LAMN that presented as a surgical emergency with strangulation ileus.

Mucocele of the appendix presenting as an exacerbated chronic tubo-ovarian abscess: A case report and comprehensive review of the literature

RATIONALE

Appendiceal mucocele is a rare entity of mucinous cystic dilatation of the appendix. It has no typical clinical presentation and is considered a potentially premalignant condition.

PATIENT CONCERNS

We present a case of accidental intraoperative finding of an appendiceal mucocele in a 54-year old woman that clinically presented with an exacerbated chronic tubo-ovarian abscess.

DIAGNOSES

Trans-vaginal ultrasonography showed an encapsulated, oval, unilocular mass above the uterus with a heteroechogenic structure, homogeneous fluid content, and smooth regular walls without inner proliferation. The histopathologic diagnosis was consistent with an appendiceal cystadenoma.

INTERVENTIONS

The patient underwent a simple appendectomy.

OUTCOMES

There were no clinical, biochemical or imaging signs of the disease recurrence at 6 months follow up.

LESSONS

To our knowledge, this is the only well-documented case of appendiceal mucocele mimicking exacerbated chronic tubo-ovarian abscess reported in the literature. Awareness of a rare entity such as an appendiceal mucocele, which is frequently misdiagnosed as a potential cause of acute abdomen, is necessary for the appropriate management strategy in order to prevent complications.