68Ga-DOTATATE PET/CT versus 111In-octreotide scintigraphy in patients with neuroendocrine tumors: a prospective study

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.

Neuroendocrine Tumors: Diagnostics

Neuroendocrine neoplasms (NEN) are rare tumors arising from neuroendocrine cells. NEN are ideally suited for a theragnostic approach due to their specific expression of somatostatin receptors (SSTR). SSTR imaging of NEN dates back to the 1980s, but has evolved recently due to the introduction of more sensitive SSTR PET radiotracers. SSTR PET is a primary imaging modality for identifying NEN and characterizing SSTR expression. SSTR PET is complementary to anatomic imaging for assessing tumor response to treatment. SSTR PET is mandated to determine eligibility for peptide receptor radionuclide therapy. Here, the role of imaging to aid management of NEN is reviewed.

Synchronous Endometrial Cancer Detected on 68 Ga-DOTATATE PET/CT

ABSTRACT

A 50-year-old woman with history of metastatic neuroendocrine tumor underwent a follow-up PET/CT with 68 Ga-DOTATATE. An enlarged uterus with diffuse increased uptake warranted further investigation with an MRI that showed mass-like thickening of the endometrium, T2 hyperintensity, lobulated contour, and invasion of more than 50% of the myometrium. Biopsy revealed endometrial carcinoma with mucinous features. Mild to moderate uptake of the 68 Ga-DOTATATE by the uterus can be a normal physiological finding; however, it should prompt further investigation, particularly in a postmenopausal woman with concerning imaging or clinical findings.