Imaging and pathological features of primary hepatic neuroendocrine carcinoma: An analysis of nine cases and review of the literature

Abstract

The present study aimed to analyze the imaging features and pathological basis of primary hepatic neuroendocrine carcinoma (PHNEC). A retrospective analysis of the imaging and pathological features of nine PHNEC cases was carried out at The Second Xiangya Hospital of Central South University (Changsha, China). The nine patients were subjected to dynamic contrast-enhanced computed tomography (CT) scanning of the liver and pathological diagnosis of the tissue samples. In addition, two patients were subjected to magnetic resonance imaging (MRI). CT scanning revealed the presence of single or multiple masses in the liver with a maximum diameter of 1-10 cm. These hepatic masses were of low density as showed by plain CT. These masses showed uneven or annular enhancement at their margins in the arterial phase. The venous portal phase showed consistent or declined enhancement and the delayed phase showed light enhancement in these masses. In addition, multiple intrahepatic nodules with long T1 and T2 signal intensities and obvious enhancement were observed by MRI in one patient, while intrahepatic lesions with moderate length T2 signal intensities and light enhancement not visible on the T1 image were observed in another patient. Pathological analysis revealed that the tumor cells exhibited morphological diversity. Immunohistochemical staining revealed that the tumor cells were chromogranin A- and synaptophysin-positive, and carcinoembryonic antigen-, hepatocytic antigen- and α-fetoprotein-negative. Imaging methods, including CT and MRI, are useful for the diagnosis of PHNEC; however, pathological examination is required for a final, definite diagnosis.

Keywords: computed tomography; magnetic resonance imaging; pathology; primary hepatic neuroendocrine carcinoma.

Figure 1

Poorly differentiated neuroendocrine carcinoma in a 57-year-old male. (A) Precontrast computed tomography showed a single mass in the left hepatic lobe with a maximum cross-section size of 6.5×5.0 cm, clear boundaries and uneven density. A liquefied necrotic area in the center of the focus was observed. (B) In enhancement scanning, a mild and uneven enhancement was observed at the edge of the mass in the arterial phase. (C and D) A decline in enhancement was observed in the portal venous and delayed phases, respectively. (E and F) Hematoxylin-eosin staining (magnification, ×100 and 200, respectively) showed the poorly differentiated cancer cells to be smaller, with less cytoplasm, angular and trachychromatic nuclei and karyokinesis.

Figure 2

Well-differentiated neuroendocrine carcinoma in a 34-year-old female. (A) Precontrast computed tomography showed multiple lumps of various sizes in the right and left hepatic lobes with a maximum cross-section size of 6×5 cm, clear boundaries and uneven density. A liquefied necrotic area in the center of the largest focus was observed. (B) In enhancement scanning, an annular enhancement was observed in the arterial phase. (C and D) A decline in the enhancement was observed in the portal venous and delayed phases, respectively. (E–J) Magnetic resonance imaging showed multiple long T1 and T2 signal foci in the liver, which were nodular and lumpy which were markedly enhanced. (K and L) Hematoxylin-eosin staining (magnification, ×100 and 200, respectively) revealed morphological diversity of the tumor cells and vessel-like arrangement in parts, with similar morphological features and limited interstitial substance.

Figure 3

Carcinoid in a 24-year-old female. (A) Precontrast computed tomography showed multiple lumps of various sizes in the right and left hepatic lobes with obscure boundaries, uniform density and a maximum diameter of 7.5 cm. (B) In enhancement scanning, obvious enhancement was observed in the arterial phase and an annular enhancement was shown in the largest mass. (C and D) A decline in enhancement was observed in the portal venous and delayed phases, respectively. (E and F) Hematoxylin-eosin staining (magnification, ×100) and immunohistochemical staining, respectively. The tumor cells showed morphological diversity and vessel-like arrangement in parts, with similar morphological features and limited interstitial substance.

Figure 4

Poorly differentiated neuroendocrine carcinoma in a 46-year-old female. (A) Precontrast computed tomography showed multiple lumps of various sizes in the right and left hepatic lobes with obscure boundaries, uniform density and a maximum diameter of 10 cm. (B) In enhancement scanning, obvious enhancement was observed in the arterial phase and an annular enhancement was identified in the largest mass. (C and D) The enhancement was observed to decline in the portal venous and delayed phases, respectively. (E and F) Hematoxylin-eosin staining (magnification, ×200 and 100, respectively) revealed the poorly differentiated cancer cells to be smaller, with less cytoplasm, angular and trachychromatic nuclei and karyokinesis.

Figure 5

Well-differentiated neuroendocrine carcinoma in a 43-year-old female. (A) Precontrast computed tomography showed multiple intrahepatic lumps with clear boundaries, uniform density and diameters of <2cm. (B) In enhancement scanning, an annular enhancement was observed in the arterial phase and (C and D) the enhancement was seen to decline in the portal venous and delayed phases, respectively. (E) Hematoxylin-eosin staining (magnification, ×100) revealed morphological diversity of the tumor cells and vessel-like arrangement in parts, with similar morphological features and limited interstitial substance.

Figure 6

Poorly differentiated neuroendocrine carcinoma in a 57-year-old male. Foci were (A) not visible in plain computed tomography, (B) were clearly visible in the arterial phase and (C) disappeared in the portal venous and (D) delayed phases. No multiple intrahepatic nodules were observed in (E) magnetic resonance imaging T1- and (F) T2-weighted images. Relatively long signals were observed in (G) T2-weighted fat suppression and (H) T1 enhancement images. (H) The foci were unevenly enhanced in T1 enhancement scanning. (J and K) HE staining (magnification, ×100 and 200, respectively) and (L) immunohistochemical staining revealed a number of tumor cells to be uniformly small- to medium in size, with unclear cytoplasmic boundaries and round and regular nuclei arranged flakily, uniformly and in clusters, or like a chrysanthemum.