CT- and ultrasound-characteristics of hepatic lesions in patients with multiple endocrine neoplasia syndrome. A retrospective image review of 25 cases

Abstract

Introduction Liver metastases from neuroendocrine tumors in multiple endocrine neoplasia syndrome are common (75%) and significantly impairs the prognosis. Characterisation of liver lesions in these patients is challenging, as liver metastases are difficult to differentiate from benign liver lesions such as haemangioma. Methods In this study we aimed to characterize the radiological findings of hepatic metastases in MEN patients. The findings of contrast-enhanced CT were considered for the main diagnosis. We retrospectively evaluated 25 patients with MEN-syndrome (10 MEN1/ 15 MEN2) including 11 men and 14 women between 28–62 years of age. Results Liver metastases (48%, 12/25) and hemangioma (40%, 10/25) were the most common liver lesions among our patients. The most common primary tumors in our MEN1 and MEN2 patients with liver metastases were of pancreatic neuroendocrine tumor (70%, 7/10) und medullary thyroid carcinoma (100%, 15/15) origin, respectively. CT-characteristics were grouped into three main categories, depending on contrast dynamics. The majority of hepatic metastases (75%, 14/25) are presented as multiple lesions with a slow growth in an average 5 years of follow-up-period. We were able to find a common CT pattern and categorise these for each MEN-syndrome. Hepatic metastases in MEN1 presented commonly a blurred arterial enhancement with a low portal venous enhancement and less frequently a prominent enhancement in the arterial phase, which mimics the classical haemangioma. In MEN2 the liver metastases exhibited disseminated mixed hyper- and hypo-enhanced lesions in CT-scans. Moreover, lesion calcifications are pathognomonic in MEN2. The main limitation of this study is the missing histopathological confirmation in the majority of cases. Conclusions In this retrospective imaging study, we were able to categorise and find a common CT pattern for hepatic lesions in patients with MEN-syndrome. In order to differentiate these lesions sufficiently, a combination of a 3-phasic CT-scan with US is required. Other liver specific imaging modalities (MRI, CEUS, SMS-PET/CT) should complement the diagnosis in individual cases.

18F-FDG-PET/CT Findings of a Primary Hepatic Neuroendocrine Tumor: A Case Report and Literature Review

“…In contrast, In-111 octreotide scanning and 68 Ga-DOTA-somatostatin analogue-PET/CT are specific receptor imaging techniques for neuroendocrine tumors with a higher positive imaging rate for grade 1 and grade 2 tumors. They may also be useful for diagnosing and staging grade 3 tumors [9][10][11].…”

Liver Imaging in Gastroenteropancreatic Neuroendocrine Neoplasms

“…30 Peptide receptor radionuclide therapy has proven to be an effective treatment for metastatic GEP-NETs. 31 18 F-FDG PET-CT has a lower sensitivity for detecting small and well-differentiated NETs (G1 and G2) but remains important for staging, prognostication, and treatment response evaluation of high-grade NENs (Fig. 6).…”

“…In particular, tumor-to-liver ratio, calculated as SUVmax divided by SUVmean of the liver, has been proven to be the only independent prognostic factor for patients who receive lanreotide therapy 30 . Peptide receptor radionuclide therapy has proven to be an effective treatment for metastatic GEP-NETs 31 …”