Liver metastases of neuroendocrine tumors: is it possible to diagnose different histologic subtypes depending on multiphasic CT features?

Hypovascular pancreatic neuroendocrine tumor with hepatic metastases: A case report and literature review

“…Typically, the imaging findings of hepatic NET metastases include multiple solid lesions that are hypervascular. The cystic degeneration of a metastatic hepatic NET can be observed due to necrosis [13 , 14] . In hepatic NET metastases, calcification is uncommon, and hepatic tumors with a fluid-fluid level are highly suggestive of NET metastases [5] .…”

“…In hepatic NET metastases, calcification is uncommon, and hepatic tumors with a fluid-fluid level are highly suggestive of NET metastases [5] . According to Gulpinar et al [14] , arterial phase imaging is especially crucial in patients with NET metastases from the pancreas because 100% of patients with NETs metastases were hyperattenuating on the arterial phase, whereas 80.2% of patients were isoattenuating on the portal venous phase. According to Abdallah et al [5] , the enhancement pattern can suggest the site of the primary NET: a hypervascular tumor without washout on the portal venous phase suggests that the pancreas is the primary tumor site, whereas a hypervascular lesion with washout on the portal venous phase indicates a gastrointestinal origin.…”

Radioembolization for Metastatic Neuroendocrine Tumors

“…Explanted livers treated with TARE (whether yttrium-90 ( 90 Y) resin or glass microspheres) demonstrated preferential accumulation of the radioactive microspheres mainly at the periphery and in nonnecrotic parts of tumors as opposed to normal liver parenchyma. 15,16 NETLMs, especially from GEP-NETs, are usually hypervascular on arterial phase of multiphasic cross-sectional imaging, 17 which theoretically make them an ideal target of intra-arterial delivery of therapy. However, a basic approach of evaluating one time point of arterial hyperenhancement did not correlate with outcome of TARE in a small study of 17 patients with NETLMs.…”

“…21 Unfortunately, this study did not include any patients with metastatic NET, and therefore, extrapolation of the findings to NETLMs is limited. The majority of GEP-NETs are hypervascular as determined by angiography and basic enhancement pattern on cross-sectional imaging 17 (►Fig. 1).…”

“…18 This lack of correlation between tumoral enhancement at one time-point multiphasic imaging and post-TARE outcomes was also noted when studying 137 patients with multiple histologies (only 19 with NETLMs). 19 These findings could be related to the small number of patients included in these retrospective studies, wide variety of tumor types, different imaging characteristics and tumor enhancement depending on the site of origin, 17 and/or subjective basic imaging techniques used in determining tumor vascularity. 19 Other more sophisticated techniques investigating arterial tumor enhancement fraction (the quotient of arterial phase enhancement divided by portal venous phase enhancement) predicted response to TARE in colorectal cancer.…”