Duodenal neuroendocrine tumors: retrospective evaluation of CT imaging features and pattern of metastatic disease on dual-phase MDCT with pathologic correlation

Abstract

Purpose The purpose of the study is to evaluate the CT appearance and pattern of metastatic disease of patients with surgically resected well-differentiated duodenal neuroendocrine tumors who underwent pre-operative dual-phase CT. Methods Clinical and pathologic records and CT images of 28 patients (average age 58.0 years) following Whipple procedure were retrospectively reviewed. The size, morphology (polypoid, intraluminal mass or wall thickening, intramural mass), location, CT attenuation in the arterial and venous phases, and the presence of lymph node or liver metastases were recorded. Results On CT, 19 patients (67.8%) had neuroendocrine tumors manifested as polypoid or intraluminal masses (38 lesions, multiple tumors in 3 patients), 4 patients (14.3%) had tumors manifested as wall thickening or intramural masses, and in 5 patients (17.9%), the primary tumor was not visualized. Lesions not seen at CT were less than 0.8 cm on pathologic diagnosis. The mean size of polypoid tumors on CT was 1.2 cm (range 0.3–3.8 cm); 24 tumors were 1.0 cm or smaller, and 14 tumors were larger than 1.0 cm. Most lesions were hypervascular in the arterial phase (19/23 patients) with an increase in tumor enhancement in the venous phase in 14 patients (60.9%), decrease in enhancement in 7 patients (30.4%), and no change in enhancement in 2 patients (8.7%). Thirteen patients (46.4%) had metastatic disease from carcinoid tumor, most commonly regional enhancing lymphadenopathy. Conclusion Duodenal carcinoid tumors commonly appear as an enhancing mass in either the arterial or venous phases. If a primary tumor is not seen in the duodenum, adjacent enhancing lymphadenopathy can be a clue to the presence of a duodenal carcinoid tumor.

Gastrointestinal neuroendocrine neoplasms (GI-NENs): hot topics in morphological, functional, and prognostic imaging

“…CT enterography has been shown to be useful in depicting small bowel parietal abnormalities and to be superior to conventional CT in this field; it has already been described by Kamaoui et al that the sensitivity of CT enteroclysis in identifying small bowel NENs is 100% with a specificity of 96% [31]. At the time of diagnosis, approximately, half of patients with GI-NENs manifest advanced disease with metastases, most frequently localized to loco-regional lymph node stations, liver parenchyma, or bone [12][13][14][15] (Figs. 3, 4).…”

“…Radiologic imaging plays a key role in the diagnosis, staging, and follow-up of GI-NENs [ 4 , 14 , 15 ].…”

“…Diagnostic imaging plays an important role in diagnosis, staging, and follow-up of GI-NENs [4,14]. Several imaging techniques are used for this objective, in particular in the field of morphology imaging, we have abdominal ultrasound (US), contrast-enhanced computed tomography (CECT), and magnetic resonance imaging (MRI); for functional imaging, we rely on somatostatin receptor scintigraphy with 111 Indium-pentetreotide ( 111 In-Octreoscan), 68 Ga-labelledsomatostatin analogues ( 68 Ga-DOTA-peptides) positron emission tomography/computed tomography (PET/TC), and 18 FFluorodeoxyglucose-positron emission tomography ( 18 F-FDG-PET) [11,14].…”

Diagnostic imaging of gastrointestinal neuroendocrine tumours (GI-NETs): relationship between MDCT features and 2010 WHO classification

“…Contrast-enhanced MDCT has allowed an optimization of scan protocols, with many advantages, including (1) very rapid scan times reducing movement artefacts; (2) contrast-enhanced images with arterial and portal phase and (3) the ability to reformat the images in thinner slices, in order to improving resolution and allowing the images to be viewed optimally in different anatomical planes. For these reasons, contrast-enhanced MDCT is the main imaging modality for diagnosis, staging, preoperative evaluation and post-treatment follow-up of NET [2][3][4]. MDCT images of GI-NETs usually appear as a hyper-enhancing nodular mass arising from the bowel wall or as a regional uniform bowel wall thickening [4,5].…”

Extra‐pulmonary primary small‐cell neuroendocrine carcinoma arising from the duodenum: rare tumor, unusual location

“…Although the majority of duodenal NETs are sporadic, they may occasionally be associated with distinct syndromes such as neurofibromatosis type 1 (NF‐1) or multiple endocrine neoplasia type 1 (MEN‐1) . According to a retrospective study of 28 patients who underwent surgical resection for well‐differentiated duodenal NETs, all tumors were noted to demonstrate both arterial and venous phase enhancement during CT examination . This is in contrast to an adenocarcinoma, which is hypovascular and hence nonenhancing.…”