Primary hepatic neuroendocrine neoplasm diagnosed by somatostatin receptor scintigraphy: A case report

Abstract

BACKGROUND Primary hepatic neuroendocrine neoplasm (NEN) is a rare condition, and it is difficult to differentiate between primary and metastatic hepatic NENs. Herein, we report a case of primary hepatic NEN that initially mimicked a hemangioma but showed a gradual increase in size on long-term careful observation. CASE SUMMARY A 47-year-old woman was incidentally diagnosed with a 12-mm liver mass, suspected to be a hemangioma. Since then, regular follow-up had been carried out. Ten years later, she was referred to our institute due to the tumor (located in segment 4) having increased to 20 mm. Several imaging studies depicted no apparent extrahepatic lesion. Positron emission tomography (PET)/computed tomography exhibited significant accumulation in the mass lesion, which made us consider the possibility of malignancy. Left hepatectomy was performed. The histopathological diagnosis was neuroendocrine tumor grade 2, with somatostatin receptor 2a/5 positivity. Postoperative somatostatin receptor scintigraphy (SRS) showed no other site, leading to the diagnosis of NEN of primary hepatic origin. The gradual growth of the hepatic NEN over 10 years suggested that it was likely to be a primary liver tumor. CONCLUSION In this case, positivity on PET and postoperative SRS may have helped determine whether the tumor was primary or metastatic.

Primary Hepatic Neuroendocrine Carcinoma: A Rare Entity

“… 8 Contrast-enhanced CT scans often show primary NETs as cystic lesions with arterial phase contrast and portal phase washout due to hypervascularity, similar to HCC. 8 , 9 On magnetic resonance imaging, they typically appear hypointense on T1-weighted images and hyperintense on T2-weighted images. 9 Distinguishing primary from extrahepatic NETs relies on radiographic studies, as histology alone is insufficient.…”

“… 8 , 9 On magnetic resonance imaging, they typically appear hypointense on T1-weighted images and hyperintense on T2-weighted images. 9 Distinguishing primary from extrahepatic NETs relies on radiographic studies, as histology alone is insufficient. 8 Positron emission tomography scans using 11 C-5 hydroxytryptophan tracer have successfully identified the primary tumor in 84% of cases but are limited to a few medical centers.…”

“… 7 Surgical intervention has shown superior efficacy with a 74% 5-year survival rate and an 18% recurrence rate, depending on the tumor's size and location. 7 , 9 Alternative modalities such as selective hepatic artery embolization, radiofrequency ablation, or hepatectomy with liver transplantation may be necessary for tumors involving both liver lobes. 7 Medical options for unsuitable surgical transarterial chemoembolization candidates include transarterial chemoembolization, chemotherapy, local ablation, or somatostatin analogs.…”

Extended Left Hemihapatectomy with Right Hepatic Artery Reconstruction for Primary Hepatic Neuroendocrine Neoplasm: A Brief Report

“…Noro et al reported a case of PHNEN in 2023, but in their case the tumor exhibited liquid components and mural solid nodules and was initially diagnosed as mucinous cystic carcinoma [13]. In a case reported by Yahia et al, the tumor presentation on imaging was akin to hepatocellular carcinoma or cholangiocarcinoma [14], and Akabane et al reported a lesion that mimicked a hemangioma [15]. To the best of our knowledge, this is the first report of a case that presented with IgG4related disease.…”