Long-term outcomes in pediatric appendiceal carcinoids: Turkey experience

Characteristics and Management of Children with Appendiceal Neuroendocrine Neoplasms: A Single-Center Study

BACKGROUND/OBJECTIVES

Appendiceal neuroendocrine neoplasms (ANENs) are usually found incidentally during histology examination after appendectomy for appendicitis. Due to their rarity in pediatric populations, there is no consensus on treatment or follow-up. The analysis of patients with ANENs of our and other studies will increase the understanding of this tumor.

METHODS

Pediatric patients with ANENs were uniformly managed at our center between 1998 and 2023. Patients' presenting symptoms, surgery, tumor histology, post-surgical work-up, follow-up and outcome were analyzed.

RESULTS

Our report describes 17 patients with a diagnosis of ANEN after appendectomy. The median age was 14 years (range of 4-17 years). Tumors were located at the tip of the appendix in 58.8% of cases and only one had a diameter >1 cm. All were well-differentiated tumors with free resection margins. The submucosa was invaded in five cases, muscularis propria in eight and subserosa in four. Post-appendectomy work-up included tumor marker measurement, abdominal ultrasound and computed tomography or magnetic resonance imaging, chest X-ray and octreotide scintigraphy. No residual tumors or metastases were detected. Additional surgery was not necessary. Follow-up was carried out for a median duration of 6 years (range of 1-10 years). Only one patient was lost to follow-up and all other patients are alive without tumor recurrence.

CONCLUSIONS

The tumor characteristics of our patients confirmed data from the literature. With the lack of a sufficient number of large prospective trials, it is important to add more information to confirm the benign nature and excellent outcome of this tumor, even without additional surgery. Consensus guidelines are needed for ANENs in pediatric populations.

Lymph node metastases are more frequent in paediatric appendiceal NET ≥1.5 cm but without impact on outcome - Data from the German MET studies

BACKGROUND

Paediatric appendiceal neuroendocrine tumours (appNET) are very rare tumours, mostly detected incidentally by histopathological evaluation after appendectomy. Treatment recommendations are based on adult data considering high-risk NET as defined by European Neuroendocrine Tumour Society (ENETS) guidelines for completion right-sided hemicolectomy (RHC). Recent data suggest that less aggressive therapy may be justified.

PROCEDURE

Analysis of children and adolescents with appNET prospectively registered with the German Malignant Endocrine Tumour (MET) studies between 1997 and 2022.

RESULTS

By December 2022, 662 patients (64.7% females, 35.3% male) had been reported. Median age was 13.3 years [4.5-17.9], median duration of follow-up 2.2 years [0-10.9]. No distant metastases were reported. Tumour size was <1 cm in 63.5%, 1-2 cm in 33.2%, and >2 cm in 3.2% of patients. WHO grade 1 and 2 tumours were diagnosed in 76.9% and 23.1% of patients, respectively. Lymphovascular invasion and lymph node metastases were associated with tumour size ≥1.5 cm. 27.0% of patients presented with high-risk NET according to ENETS criteria. Of those, only 55.9% underwent secondary oncological right hemicolectomy. Neither distant metastases, nor recurrences or disease-related deaths occurred in patients with appendectomy only as well as in patients with completion RHC. Overall and event-free survival were both 100%.

CONCLUSIONS

Internationally harmonized consensus recommendations on treatment of children and adolescents with appendiceal NET are urgently needed to avoid completion RHC in high-risk patients.

Incidence and Management of Appendiceal Neuroendocrine Tumors in Pediatric Population: A Bicentric Experience with 6285 Appendectomies

BACKGROUND

Neuroendocrine tumors (NETs) are rare tumors that arise from neuroendocrine cells and are the most common tumors of the appendix. NETs of the appendix usually cause no symptoms and often go unnoticed until they cause acute appendicitis or are discovered during an accidental appendectomy. As the trend towards the conservative treatment of acute appendicitis increases in the pediatric population, the question arises as to whether the majority of NETs go undetected and are only discovered at an advanced stage. The purpose of the proposed study is to review the incidence and outcomes of treatment for NETs of the appendix in children and include the data presented in the data pool for further review.

METHODS

From 1 January 2009 to 1 November 2023, a total of 6285 appendectomies were performed in two large pediatric centers in Croatia. After a retrospective review of the case records and histopathologic findings, a total of 31 children (0.49%) were diagnosed with NET of the appendix and included in the further analysis. The primary outcome of this study was the incidence and treatment outcome of pediatric patients diagnosed with NET of the appendix. Secondary outcomes included the patients' demographic, clinical, and laboratory data and the histopathologic characteristics of tumor species.

RESULTS

The overall incidence of NETs of the appendix was stable over the study years, with minor fluctuations. The median age of patients was 14 (interquartile range-IQR: 12, 16) years, with a female predominance (64.5%). The majority of patients (96.8%) presented with acute abdominal pain and underwent appendectomy because acute appendicitis was suspected. Acute appendicitis was confirmed by histopathology in 18 (58%) cases. NETs of the appendix were not detected preoperatively in any of the patients. Among patients with confirmed acute appendicitis, most (n = 14; 77.8%) were found to have non-perforated acute appendicitis. In most children, the tumor was located at the tip of the appendix (n = 18; 58.1%), and the majority of tumors had a diameter of less than 1 cm (n = 21, 67.7%). The mitotic count (n = 25, 80.6%) and Ki-67 proliferation index (n = 23, 74.2%) were low in most patients, so most tumors were classified as NET G1 (n = 25, 80.6%), while NET G2 and NET G3 were found in four (12.9%) and two (6.5%) patients, respectively. All children were treated with appendectomy only. The median follow-up time was 54 (IQR: 24, 95) months.

CONCLUSIONS

The incidence of appendiceal NET among pediatric patients is very low. NET occurs most frequently in adolescents, with a female predominance. Most tumors are less than 1 cm in diameter, located at the tip, and associated with non-perforated appendicitis. Appendectomy is the treatment of choice, and major surgery was not necessary in our cohort.

Management and outcome of high-risk neuroendocrine tumors of the appendix in children; A systematic review

This study systematically reviewed the literature to investigate the value of secondary surgery for children with a high-risk neuroendocrine tumor (NET) of appendix. A systematic search was performed in PubMed, Embase and Web of Science. All randomized controlled trials, cohort studies, and case series reporting on the management and outcomes of patients (<20 years) with a histopathologically proven NET of the appendix were eligible for inclusion. Two authors independently selected eligible articles, assessed risk of bias, and extracted data. The outcomes of patients with a high-risk NET treated with secondary surgery were compared to those treated without secondary surgery. Primary outcomes were recurrence rate and disease-free survival. The literature search yielded 667 articles, of which 29 were included. These studies reported on 1112 patients, of whom 145 (13%) had high-risk NET. Heterogeneity between studies was large and risk of bias was serious in 26 and moderate in three studies. Secondary surgery after primary appendectomy was performed in 64 of 145 patients (44%). Length of follow-up ranged between 0 and 612 months. In both treatment groups no recurrences were reported, and thus disease-free survival was 100%. Based on current literature, the value of secondary surgery for pediatric high-risk NET of the appendix may be questioned. However, evidence is scarce, of low-quality, and heterogeneity between studies is large. Large international studies with adequate follow-up are needed to generate high-quality evidence on this topic.

Delayed Detection of a Carcinoid Tumor after Conservative Therapy for Appendicitis in a 13-Year-Old Boy and a 17-Year-Old Girl

Acute appendicitis is common in children and adolescents. Recently, conservative antibiotic treatment is regarded to be a safe approach to treat uncomplicated appendicitis. It is already established as initial treatment in cases of perforated appendicitis with perityphlitic abscess, commonly followed by interval appendectomy. We report on a 13-year-old boy with uncomplicated appendicitis and a 17-year-old girl with complicated, perforated appendicitis and perityphlitic abscess in whom initially successful antibiotic treatment led to a delay in detection of a carcinoid tumor (neuroendocrine tumor, NET) of the appendix. NET of the appendix, with an incidence of 0.03 to 0.8% in the pediatric population undergoing appendectomy for acute appendicitis, are usually incidental findings after appendectomy with no secure method for detection prior to surgery. Raising concern about this rare but severe disease, we recommend information of patients and their parents about the potential risk of belated diagnosis before opting for conservative their treatment of acute appendicitis. Furthermore, patients successfully treated conservatively require a close follow-up by ultrasound. In presence of any conspicuous finding, especially on imaging, appendectomy should be considered.

Appendiceal carcinoid in a pediatric patient with Peutz-Jeghers syndrome: A case report and comprehensive literature review

RATIONALE

Peutz-Jeghers syndrome (PJS), a rare autosomal dominant disorder, is characterized by mucocutaneous pigmentations, hamartomatous polyps in the gastrointestinal tract, and a high risk of developing various malignancies. To the best of our knowledge, only 1 case of appendiceal carcinoid associated with PJS has been previously reported in the pediatric population.

PATIENT CONCERNS

We report a 7-year-old girl who was admitted for severe, intermittent abdominal pain and cramps, nausea, and vomiting. Multiple brown melanotic macules on the lips, buccal mucosa, and the tongue were noted.

DIAGNOSIS

A plain abdominal X-ray in a standing position revealed dilated intestinal loops with multiple air-fluid levels. A computed tomography scan of the abdomen showing a "coffee bean" appearance of the jejunal loop with a transition point to the duodenal loop. Axial-contrast-enhanced computed tomography scan of the abdomen showing dilated jejunum loops, filled with fluid with the swirled appearance of mesentery typical for volvulus. The diagnosis of PJS was based on clinical findings along with the histopathologic confirmation of the hamartomatous polyps.

INTERVENTIONS

An emergency laparotomy was performed, revealing a jejunojejunal intussusception starting 40 cm from the duodenojejunal flexure. Jejunotomy revealed that a lead-point intussusception was a necrotic hamartomatous polyp. After resecting the involved jejunal necrotic segment, including the polyp, end-to-end jejuno-jejunal anastomosis was performed. Further exploration revealed the presence of a jejunal mass 80 cm from the duodenojejunal flexure identified as another hamartomatous pedunculated polyp. The polyp was resected, and the enterotomy was then closed transversely. The grossly normal appendix was also removed.

OUTCOMES

Clinical findings along with the histopathologically confirmed hamartomatous polyps were consistent with PJS. An appendiceal carcinoid (well-differentiated neuroendocrine tumor, European Neuroendocrine Tumor Society stage pT2) was incidentally detected during histological examination of the appendix. The patient and parents were counseled accordingly, focusing on active surveillance and control of symptoms. Two additional hamartomatous polyps (gastric and jejunal) were detected endoscopically and resected in the fourth postoperative week. A regular, 1-year follow-up and surveillance revealed no complications or recurrences.

LESSONS

Unusual neoplasms can occasionally be encountered in well-defined syndromes such as PJS. Therefore, active follow-up and surveillance are mandatory for all patients with PJS.

Management of pediatric appendiceal carcinoid: a single institution experience from 5000 appendectomies

AIM OF THE STUDY

Appendiceal carcinoid (neuroendocrine tumor or NET) is a rare neuroendocrine neoplasm often found incidentally following appendectomy for appendicitis. Surgery for appendicitis is currently under scrutiny and children are increasingly managed conservatively with antibiotics alone. Herein, we aimed to review our experience with the management of appendiceal carcinoids at our institution.

METHODS

Following ethical approval, we reviewed the charts of all patients who underwent appendectomy for appendicitis at our institution between 2000 and 2018. The pathology registry was consulted to identify children diagnosed with appendiceal carcinoid. Outcome measures included incidence, demographics, and management.

MAIN RESULTS

During the study period, 32 children (23 female) had an appendiceal carcinoid confirmed at pathology. Of these, 13 were initially treated with appendectomy (total of 5,059 appendectomies: 0.3% incidence). The other 19 had an appendectomy elsewhere by an adult general surgeon and were referred to our institution for further management. Overall, the mean age at diagnosis was 13 ± 2.7 years and all patient had a preoperative diagnosis of appendicitis, none of suspected carcinoid. Most children (75%) had acute non-perforated appendicitis. The overall mean size of the lesion was 1 ± 0.9 cm, with a > 2 cm lesion in 3 patients. Following diagnosis, 12 children (38%) underwent an ileocolic resection, due to carcinoid size, invasiveness, and margin clearance.

CONCLUSIONS

In our cohort, the incidence of appendiceal carcinoid among children with appendicitis is very low. Most carcinoids are small, located at the tip, associated with non-perforated appendicitis, and present in girls. Most were treated with appendectomy alone, with more extensive surgery performed in one third of children.