Pancreatic Neuroendocrine Tumor Detected by 99mTc-MIBI SPECT/CT: A Case Report
Abstract: Pancreatic neuroendocrine tumor (NET) accounts for about 1% to 2% of pancreatic tumors and for about 8% of all NETs. CT, MR imaging, and endoscopic ultrasound are common imaging modalities for the pancreatic NETs diagnosis. Somatostatin receptor imaging is of great value for diagnosing pancreatic NETs. We herein report a 57-year-old woman who presented with pancreatic NET detected by 99mTc-MIBI SPECT/CT. The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET. 99mTc-MIBI SPECT/CT seems to be a valuable tool to detect pancreatic NET.
Key Words: Neuroendocrine Tumors; Pancreas, Technetium Tc 99m Sestamibi; SPECT; X-Ray Computed Tomography
- Introduction
Neuroendocrine tumors (NETs) are relatively rare tumors arising from cells in the diffuse neuroendocrine system, which mainly occur in the gastroenteropancreatic (GEP) tract and lungs [1]. The GEP tract is the most common site of NETs [2]. Pancreatic NET accounts for about 1% to 2% of pancreatic tumors [3] and about 8% of all NETs [4]. The diagnostic imaging modalities for pancreatic NET include CT, MR imaging, endoscopic ultrasound, and somatostatin receptor imaging [5]. However, there is no report about the application of 99mTc-MIBI SPECT/CT in detecting pancreatic NET.
- Case Report
In October 2022, a 57-year-old woman with a 1-day history of persistent upper abdomen distending pain presented to our hospital. The upper abdomen distending pain aggravated after eating, with nausea and retching. The patient underwent abdominal traumatic exploratory surgery more than 30 years ago.
Routine blood test showed high level of neutrophil percentage (88.40%, reference value 40.00%-75.00%), low levels of leukomonocyte percentage (9.00%, reference value 20.00%-50.00%), monocyte percentage (1.90%, reference value 3.00%-10.00%), leukomonocyte count (0.60×109, reference value 1.10-3.20×109), and eosinophil count (0.01×109, reference value 0.02-0.52×109). Urine routine and stool routine tests were normal. The levels of electrolyte sodium, chlorine, calcium and magnesium were normal. Amylase, liver and kidney function, tumor markers alpha-fetoprotein, carcinoembryonic antigen, cancer antigen 125 (CA125), CA72-4, CA19-9, CA153 were also normal.
2.1 Plain CT and Contrast-enhanced CT of the abdomen
Abdominal plain CT showed a mass with multiple calcifications between the pancreas and the spleen. The boundary between the mass and pancreas and spleen was ill-defined (Figure 1). The maximum cross section of the mass was about 9.0 cm ×8.6 cm. Contrast-enhanced CT revealed that the upper abdominal mass was unevenly enhanced (Figure 2).
2.2 99mTc-MIBI SPECT/CT of the abdomen
99mTc-MIBI SPECT/CT was performed 5 days after the contrast-enhanced CT. Scanning began 30 minutes after 740 MBq of 99mTc- MIBI injection, 99mTc- MIBI SPECT/CT of the abdomen was performed using PRECEDENCE SPECT/CT (Philips Medical Systems, Eindhoven, Netherland). CT was performed in a spiral mode with 250 mAs/slice, 120 Kv, and slice thickness 3.0 mm, covering the entire abdomen. Immediately follow-on the CT scan, SPECT acquisition of the abdomen was done. The SPECT was equipped with low-energy, high-resolution, parallel-hole collimators. The SPECT acquisition adopted elliptic orbit with step-and-shoot acquisition using 64 angles over 360° (180° per detector), and a 20s per frame acquisition time. The SPECT data were reconstructed with attenuation correction using the CT acquisition with iterative reconstruction using the software AutoSPECT Pro and Astonish with four iterations and 16 subsets. The 99mTc- MIBI SPECT/CT fusion imaging was processed using the procedure of Fusion viewer. The SPECT slice thickness was the same as the CT.
99mTc-MIBI SPECT/CT showed that a focal radioactive concentration, with mild radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail (Figure 3).
2.3 Histopathological results
Excision of the pancreatic body and tail, upper abdominal mass and spleen was performed 2 days after 99mTc-MIBI SPECT/CT. During the operation, a pancreatic lesion was seen to expand outward and extend into the spleen. The pathology of the pancreatic lesion indicated well differentiated pancreatic NET in hematoxylin and eosin stain (Figure 4). The pathology of the spleen showed the normal spleen cells in hematoxylin and eosin stain (Figure 5). The KI-67 proliferative index was assessed at 10% (Figure 6).
- Discussion
Pancreatic NETs are often divided into functional and nonfunctional pancreatic NETs. The majority pancreatic NETs are nonfunctional [5]. The symptoms of nonfunctional pancreatic NET include abdominal or back pain, nausea, vomiting, pancreatitis, and obstructive jaundice [5]. Patients with functional pancreatic NETs often manifest symptoms caused by hormone production of the tumor, leading to an earlier diagnosis [8].
CT, MR imaging and endoscopic ultrasound are common imaging modalities for the pancreatic NETs diagnosis. In addition, somatostatin receptor imaging is of great value for the diagnosis of pancreatic NETs [9], but the method is not easily available in our country. Here we present a case of pancreatic NETs detected by 99mTc-MIBI SPECT/CT.
99mTc-MIBI is a lipophilic univalent cationic agent. Driven by the cytoplasmic and mitochondrial transmembrane potential gradients, 99mTc-MIBI penetrates reversibly into the cytoplasm and then concentrates in mitochondria [6]. There were greater electrical gradients from outside the cell to mitochondria in carcinoma cells than in normal epithelial cells, and the uptake of 99mTc-MIBI can increase tenfold in the carcinoma cells [6]. 99mTc-MIBI SPECT/CT may be effective for detecting lymph node and lung metastases in patients with differentiated thyroid carcinoma [10]. 99mTc-MIBI SPECT can also be used in differentiating benign from malignant solitary pulmonary nodes and thyroid nodes [11,12]. Lu C et al [7] had reported a case of mediastinal typical carcinoid tumor detected by 99mTc-MIBI SPECT/CT.
Our patient was 57 years old, and the symptoms started 1 day previously. The age for the occurrence of pancreatic NETs is equivalent to the mean age previously identified for this type of tumor [5]. Abdominal plain CT showed a mass with multiple calcifications between the pancreas and spleen. The boundary between the mass and pancreas and spleen was ill-defined. These findings indicated that the tumor might originate from the spleen or pancreas. Contrast-enhanced CT revealed that the mass was unevenly enhanced. This indicated the possibility of malignant tumor. However, 99mTc-MIBI SPECT/CT showed that a focal radioactive concentration, with mild radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail. This sign strongly suggests that the upper abdominal mass originaed from the pancreas. The CT manifestations of the pancreatic tissue corresponding to the focal radioactive concentration were solid and homogenous. Previous study reported that pancreatic NETs tended to appear as solid and homogenous lesions in CT imaging [9]. The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.
- Conclusions
99mTc-MIBI SPECT/CT seems to be valuabe in diagnosing pancreatic NETs. Anyway, subsequent large sample studies are needed to confirm it.
Author Contributions: C.J.L.: conception of the idea and design of the research, data analysis, manuscript writing, and approval of the final version. Y.C.P., D.Y.H.: data analysis, manuscript writing. All authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: This retrospective study was approved by the local ethical and radiation safety committees and was conducted in compliance with the Helsinki Declaration 20.
Informed Consent Statement: Informed consent was obtained from the subject at the time of admission.
Data Availability Statement: Not applicable.
Conflicts of Interest: The authors declare no conflict of interest.
References
[1] Ohmoto, A.; Morizane, C. Genomic Profiles and Current Therapeutic Agents in Neuroendocrine Neoplasms. Curr Drug Targets. 2020, 21, 389-405.
[2] Iabichino, G.; Di Leo, M.; Arena, M.; Rubis Passoni, GG.; Morandi, E.; Turpini, F.; Viaggi, P.; Luigiano, C.; De Luca, L. Diagnosis, treatment, and current concepts in the endoscopic management of gastroenteropancreatic neuroendocrine neoplasms. World J Gastroenterol. 2022, 28, 4943-4958.
[3] Ito, T.; Sasano, H.; Tanaka. M.; Osamura, R.Y.; Sasaki, I.; Kimura, W.; Takano, K.; Obara, T.; Ishibashi, M.; Nakao, K.; et al. Epidemiological study of gastroenteropancreatic neuroendocrine tumors in Japan. J Gastroenterol. 2010, 45, 234-243.
[4] Dasari, A.; Shen, C.; Halperin, D.; Zhao, B.; Zhou, S.; Xu, Y.; Shih, T.; Yao, J.C. Trends in the Incidence, Prevalence, and Survival Outcomes in Patients With Neuroendocrine Tumors in the United States. JAMA Oncol. 2017, 3, 1335-1342.
[5] Scott, A.T.; Howe, J.R. Evaluation and Management of Neuroendocrine Tumors of the Pancreas. Surg Clin North Am. 2019, 99, 793-814.
[6] Moretti, J.L.; Hauet, N.; Caglar, M.; Rebillard, O.; Burak, Z. To use MIBI or not to use MIBI? That is the question when assessing tumour cells. Eur J Nucl Med Mol Imaging 2005, 32, 836-842.
[7] Lu, C.; Wang, Z.; Wang, G.; Wang, X.; Liu, X. Superior mediastinal typical carcinoid detected by 99mTc-MIBI SPECT/CT imaging: A case report. Medicine (Baltimore). 2017, 96, e9457.
[8] Halfdanarson, T.R.; Rabe, K.G.; Rubin, J.; Petersen, G.M. Pancreatic neuroendocrine tumors (PNETs): incidence, prognosis and recent trend toward improved survival. Ann Oncol. 2008, 19, 1727– 1733.
[9] Hu, H.F.; Li, Z.; Chen, K.; Liu, M.Q.; Ye, Z.; Chen, X.M.; Zhang, Y.; Yu, X.J.; Xu, X.W.; Ji, S.R. Multimodality imaging differentiation of pancreatic neuroendocrine tumors and solid pseudopapillary tumors with a nomogram model: A large single-center study. Front Surg. 2022, 9，970178.
[10] Okudan, B.; Seven, B.; Gülaldı, N.C.M.; Çapraz, M.; Açıkgöz, Y. The Value of 99mTc-MIBI SPECT/CT in the Postoperative Assessment of Patients with Differentiated Thyroid Carcinoma. Curr Med Imaging. 2022, 18, 404-408.
[11] Xia, G.; An, C.; Ming, Z.; Guo, H.; Liu, L.; Li, Y. 18F-FDG-PET/CT versus 99Tcm-MIBI-SPECT: which is better for detection of solitary pulmonary nodules? J BUON. 2017, 22, 1246-1251.
[12] Schenke, S.A.; Campennì, A.; Tuncel, M.; Bottoni, G.; Sager, S.; Bogovic Crncic, T.; Rozic, D.; Görges, R.; Özcan, P.P.; Groener, D.; et al. Diagnostic Performance of 99mTc-Methoxy-Isobuty-Isonitrile (MIBI) for Risk Stratification of Hypofunctioning Thyroid Nodules: A European Multicenter Study. Diagnostics (Basel). 2022, 12, 1358.
Figure 1. Abdominal plain CT. A mass with multiple calcifications between the pancreas and spleen. The boundary between the mass and pancreas and spleen was ill-defined.
Figure 2. Abdominal CT with contrast: (A) arterial time, (b) venous time. The upper abdominal mass was unevenly enhanced.
Figure 3. 99mTc-MIBI SPECT/CT of abdomen. A focal radioactive concentration, with faint radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail. (A) (B) (C) transverse axis, (D) (E) (F) coronal axis.
Figure 4. The pathology the focal radioactive concentration of the pancreatic body and tail shown on 99mTc-MIBI SPECT/CT indicated well differentiated pancreatic NET in hematoxylin and eosin stain, ×200.
Figure 5. The pathology of the upper abdominal mass shown on CT indicated well differentiated pancreatic NET in hematoxylin and eosin stain, ×200.
Figure 6. Normal spleen cells in hematoxylin and eosin stain, ×100.
Figure 7. The immunohistochemical staining (Envision technique) showed KI-67 of 10%, ×400.
- Neuroendocrine Tumors
- Pancreas
- Technetium Tc 99m Sestamibi
- SPECT
- X-Ray Computed Tomography
Abstract: Pancreatic neuroendocrine tumor (NET) accounts for about 1% to 2% of pancreatic tumors and for about 8% of all NETs. CT, MR imaging, and endoscopic ultrasound are common imaging modalities for the pancreatic NETs diagnosis. Somatostatin receptor imaging is of great value for diagnosing pancreatic NETs. We herein report a 57-year-old woman who presented with pancreatic NET detected by 99mTc-MIBI SPECT/CT. The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET. 99mTc-MIBI SPECT/CT seems to be a valuable tool to detect pancreatic NET.
Key Words: Neuroendocrine Tumors; Pancreas; Technetium Tc 99m Sestamibi; SPECT; X-Ray Computed Tomography
- Introduction
Neuroendocrine tumors (NETs) are relatively rare tumors arising from cells in the diffuse neuroendocrine system, which mainly occur in the gastroenteropancreatic (GEP) tract and lungs [1]. The GEP tract is the most common site of NETs [2]. Pancreatic NET accounts for about 1% to 2% of pancreatic tumors [3] and about 8% of all NETs [4]. The diagnostic imaging modalities for pancreatic NET include CT, MR imaging, endoscopic ultrasound, and somatostatin receptor imaging [5]. However, there is no report about the application of 99mTc-MIBI SPECT/CT in detecting pancreatic NET.
- Case Report
In October 2022, a 57-year-old woman with a 1-day history of persistent upper abdomen distending pain presented to our hospital. The upper abdomen distending pain aggravated after eating, with nausea and retching. The patient underwent abdominal traumatic exploratory surgery more than 30 years ago.
Routine blood test showed high level of neutrophil percentage (88.40%, reference value 40.00%-75.00%), low levels of leukomonocyte percentage (9.00%, reference value 20.00%-50.00%), monocyte percentage (1.90%, reference value 3.00%-10.00%), leukomonocyte count (0.60×109, reference value 1.10-3.20×109), and eosinophil count (0.01×109, reference value 0.02-0.52×109). Urine routine and stool routine tests were normal. The levels of electrolyte sodium, chlorine, calcium and magnesium were normal. Amylase, liver and kidney function, tumor markers alpha-fetoprotein, carcinoembryonic antigen, cancer antigen 125 (CA125), CA72-4, CA19-9, CA153 were also normal.
2.1 Plain CT and Contrast-enhanced CT of the abdomen
Abdominal plain CT showed a mass with multiple calcifications between the pancreas and the spleen. The boundary between the mass and pancreas and spleen was ill-defined (Figure 1). The maximum cross section of the mass was about 9.0 cm ×8.6 cm. Contrast-enhanced CT revealed that the upper abdominal mass was unevenly enhanced (Figure 2).
2.2 99mTc-MIBI SPECT/CT of the abdomen
99mTc-MIBI SPECT/CT was performed 5 days after the contrast-enhanced CT. Scanning began 30 minutes after 740 MBq of 99mTc- MIBI injection, 99mTc- MIBI SPECT/CT of the abdomen was performed using PRECEDENCE SPECT/CT (Philips Medical Systems, Eindhoven, Netherland). CT was performed in a spiral mode with 250 mAs/slice, 120 Kv, and slice thickness 3.0 mm, covering the entire abdomen. Immediately follow-on the CT scan, SPECT acquisition of the abdomen was done. The SPECT was equipped with low-energy, high-resolution, parallel-hole collimators. The SPECT acquisition adopted elliptic orbit with step-and-shoot acquisition using 64 angles over 360° (180° per detector), and a 20s per frame acquisition time. The SPECT data were reconstructed with attenuation correction using the CT acquisition with iterative reconstruction using the software AutoSPECT Pro and Astonish with four iterations and 16 subsets. The 99mTc- MIBI SPECT/CT fusion imaging was processed using the procedure of Fusion viewer. The SPECT slice thickness was the same as the CT.
99mTc-MIBI SPECT/CT showed that a focal radioactive concentration, with mild radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail (Figure 3).
2.3 Histopathological results
Excision of the pancreatic body and tail, upper abdominal mass and spleen was performed 2 days after 99mTc-MIBI SPECT/CT. During the operation, a pancreatic lesion was seen to expand outward and extend into the spleen. The pathology of the pancreatic lesion indicated well differentiated pancreatic NET in hematoxylin and eosin stain (Figure 4). The pathology of the spleen showed the normal spleen cells in hematoxylin and eosin stain (Figure 5). The KI-67 proliferative index was assessed at 10% (Figure 6).
- Discussion
Pancreatic NETs are often divided into functional and nonfunctional pancreatic NETs. The majority pancreatic NETs are nonfunctional [5]. The symptoms of nonfunctional pancreatic NET include abdominal or back pain, nausea, vomiting, pancreatitis, and obstructive jaundice [5]. Patients with functional pancreatic NETs often manifest symptoms caused by hormone production of the tumor, leading to an earlier diagnosis [8].
CT, MR imaging and endoscopic ultrasound are common imaging modalities for the pancreatic NETs diagnosis. In addition, somatostatin receptor imaging is of great value for the diagnosis of pancreatic NETs [9], but the method is not easily available in our country. Here we present a case of pancreatic NETs detected by 99mTc-MIBI SPECT/CT.
99mTc-MIBI is a lipophilic univalent cationic agent. Driven by the cytoplasmic and mitochondrial transmembrane potential gradients, 99mTc-MIBI penetrates reversibly into the cytoplasm and then concentrates in mitochondria [6]. There were greater electrical gradients from outside the cell to mitochondria in carcinoma cells than in normal epithelial cells, and the uptake of 99mTc-MIBI can increase tenfold in the carcinoma cells [6]. 99mTc-MIBI SPECT/CT may be effective for detecting lymph node and lung metastases in patients with differentiated thyroid carcinoma [10]. 99mTc-MIBI SPECT can also be used in differentiating benign from malignant solitary pulmonary nodes and thyroid nodes [11,12]. Lu C et al [7] had reported a case of mediastinal typical carcinoid tumor detected by 99mTc-MIBI SPECT/CT.
Our patient was 57 years old, and the symptoms started 1 day previously. The age for the occurrence of pancreatic NETs is equivalent to the mean age previously identified for this type of tumor [5]. Abdominal plain CT showed a mass with multiple calcifications between the pancreas and spleen. The boundary between the mass and pancreas and spleen was ill-defined. These findings indicated that the tumor might originate from the spleen or pancreas. Contrast-enhanced CT revealed that the mass was unevenly enhanced. This indicated the possibility of malignant tumor. However, 99mTc-MIBI SPECT/CT showed that a focal radioactive concentration, with mild radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail. This sign strongly suggests that the upper abdominal mass originaed from the pancreas. The CT manifestations of the pancreatic tissue corresponding to the focal radioactive concentration were solid and homogenous. Previous study reported that pancreatic NETs tended to appear as solid and homogenous lesions in CT imaging [9]. The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.
- Conclusions
99mTc-MIBI SPECT/CT seems to be valuabe in diagnosing pancreatic NETs. Anyway, subsequent large sample studies are needed to confirm it.
Author Contributions: C.J.L.: conception of the idea and design of the research, data analysis, manuscript writing, and approval of the final version. Y.C.P., D.Y.H.: data analysis, manuscript writing. All authors have read and agreed to the published version of the manuscript.
Funding: This research received no external funding.
Institutional Review Board Statement: This retrospective study was approved by the local ethical and radiation safety committees and was conducted in compliance with the Helsinki Declaration 20.
Informed Consent Statement: Informed consent was obtained from the subject at the time of admission.
Data Availability Statement: Not applicable.
Conflicts of Interest: The authors declare no conflict of interest.
References
[1] Ohmoto, A.; Morizane, C. Genomic Profiles and Current Therapeutic Agents in Neuroendocrine Neoplasms. Curr Drug Targets. 2020, 21, 389-405.
[2] Iabichino, G.; Di Leo, M.; Arena, M.; Rubis Passoni, GG.; Morandi, E.; Turpini, F.; Viaggi, P.; Luigiano, C.; De Luca, L. Diagnosis, treatment, and current concepts in the endoscopic management of gastroenteropancreatic neuroendocrine neoplasms. World J Gastroenterol. 2022, 28, 4943-4958.
[3] Ito, T.; Sasano, H.; Tanaka. M.; Osamura, R.Y.; Sasaki, I.; Kimura, W.; Takano, K.; Obara, T.; Ishibashi, M.; Nakao, K.; et al. Epidemiological study of gastroenteropancreatic neuroendocrine tumors in Japan. J Gastroenterol. 2010, 45, 234-243.
[4] Dasari, A.; Shen, C.; Halperin, D.; Zhao, B.; Zhou, S.; Xu, Y.; Shih, T.; Yao, J.C. Trends in the Incidence, Prevalence, and Survival Outcomes in Patients With Neuroendocrine Tumors in the United States. JAMA Oncol. 2017, 3, 1335-1342.
[5] Scott, A.T.; Howe, J.R. Evaluation and Management of Neuroendocrine Tumors of the Pancreas. Surg Clin North Am. 2019, 99, 793-814.
[6] Moretti, J.L.; Hauet, N.; Caglar, M.; Rebillard, O.; Burak, Z. To use MIBI or not to use MIBI? That is the question when assessing tumour cells. Eur J Nucl Med Mol Imaging 2005, 32, 836-842.
[7] Lu, C.; Wang, Z.; Wang, G.; Wang, X.; Liu, X. Superior mediastinal typical carcinoid detected by 99mTc-MIBI SPECT/CT imaging: A case report. Medicine (Baltimore). 2017, 96, e9457.
[8] Halfdanarson, T.R.; Rabe, K.G.; Rubin, J.; Petersen, G.M. Pancreatic neuroendocrine tumors (PNETs): incidence, prognosis and recent trend toward improved survival. Ann Oncol. 2008, 19, 1727– 1733.
[9] Hu, H.F.; Li, Z.; Chen, K.; Liu, M.Q.; Ye, Z.; Chen, X.M.; Zhang, Y.; Yu, X.J.; Xu, X.W.; Ji, S.R. Multimodality imaging differentiation of pancreatic neuroendocrine tumors and solid pseudopapillary tumors with a nomogram model: A large single-center study. Front Surg. 2022, 9，970178.
[10] Okudan, B.; Seven, B.; Gülaldı, N.C.M.; Çapraz, M.; Açıkgöz, Y. The Value of 99mTc-MIBI SPECT/CT in the Postoperative Assessment of Patients with Differentiated Thyroid Carcinoma. Curr Med Imaging. 2022, 18, 404-408.
[11] Xia, G.; An, C.; Ming, Z.; Guo, H.; Liu, L.; Li, Y. 18F-FDG-PET/CT versus 99Tcm-MIBI-SPECT: which is better for detection of solitary pulmonary nodules? J BUON. 2017, 22, 1246-1251.
[12] Schenke, S.A.; Campennì, A.; Tuncel, M.; Bottoni, G.; Sager, S.; Bogovic Crncic, T.; Rozic, D.; Görges, R.; Özcan, P.P.; Groener, D.; et al. Diagnostic Performance of 99mTc-Methoxy-Isobuty-Isonitrile (MIBI) for Risk Stratification of Hypofunctioning Thyroid Nodules: A European Multicenter Study. Diagnostics (Basel). 2022, 12, 1358.
Figure 1. Abdominal plain CT. A mass with multiple calcifications between the pancreas and spleen. The boundary between the mass and pancreas and spleen was ill-defined.
Figure 2. Abdominal CT with contrast: (A) arterial time, (b) venous time. The upper abdominal mass was unevenly enhanced.
Figure 3. 99mTc-MIBI SPECT/CT of abdomen. A focal radioactive concentration, with faint radioactive concentration extended into the upper abdominal mass, was presented at the pancreatic body and tail. (A) (B) (C) transverse axis, (D) (E) (F) coronal axis.
Figure 4. The pathology the focal radioactive concentration of the pancreatic body and tail shown on 99mTc-MIBI SPECT/CT indicated well differentiated pancreatic NET in hematoxylin and eosin stain, ×200.
Figure 5. The pathology of the upper abdominal mass shown on CT indicated well differentiated pancreatic NET in hematoxylin and eosin stain, ×200.
Figure 6. Normal spleen cells in hematoxylin and eosin stain, ×100.
Figure 7. The immunohistochemical staining (Envision technique) showed KI-67 of 10%, ×400.