Pulmonary Neuroendocrine Tumor with Pancreatic Metastasis: A Case Report

Neuroendocrine tumors are a group of tumors that share
morphological, immunohistochemical and ultrastructural
pathology and molecular features...


Introduction
Neuroendocrine tumors are a group of tumors that share morphological, immunohistochemical and ultrastructural pathology and molecular features. The incidence of pulmonary neuroendocrine tumor is gradually increasing, leading to distant metastasis of liver, bone, brain, and adrenal gland [1]. However, pancreatic metastasis is rare, which accounted for about 0.7% [2].
We herein reported a case report of pancreatic metastases from pulmonary neuroendocrine tumor with abdominal symptoms and elevated serum CA19-9 levels. Previous studies were reviewed in order to provide some experiences regarding the diagnosis and treatment of such diseases.

Case Presentation
A 56-year-old male was admitted to the People's Hospital of Suichang County on May 10, 2019 with epigastric dull pain radiating into the posterior back for more than 20 days and had no obvious aggravation and relief factors. There were no nausea or any change in bowel movement habits and weight, and no pulmonary and nerve system symptoms were observed. Some medications for gastritis were taken by him, but no effect was achieved. 0-5ng/ml), and CA19-9 44.50U/ml(reference range: 0-37U/ml).
Enhanced CT scan showed multiple pancreatic tumors with lymph node metastasis in the retroperitoneum. Pulmonary CT showed left lung tumor with multiple metastasis (of lung in the left chest wall and lymph nodes in the hilum, mediastinum, axilla). ( Figure   1) Cranial MR suggested multiple abnormal signal nodules in both cerebellar hemispheres and considered it as metastatic. The total survival time is 9 months. Patient's informed consent was obtained to publish this case report. c. HE, x400.
The cell layers were clustered and nested, and organ-like structures were seen. The cells were small with less cytoplasm, unclear nucleoli, partial vacuoles in the nucleus and chromatin. Karyokinesis was observed with local coagulation necrosis. Primary pulmonary neuroendocrine tumors are more prone to distant metastases, and the most common tissues included liver, bone, brain, and adrenal [1,12,13]. But pancreatic metastasis is quite rare, which accounted for about 0.7% [2]. Most of the metastases are still dominated by pulmonary symptoms, which might be related to the fact that the tumor cells metastasize to the pancreas through hematogenous or lymphatic routes, but there was no infiltration of the biliopancreatic duct wall. In this case, abdominal symptoms (abdominal pain) were the first symptoms, which were relatively rare, and may be related to the tumor compression of biliopancreatic duct. In addition, different from primary pancreatic cancer, majority of the patients with metastatic pancreatic cancer had normal serum CA19-9 levels While the evidence supporting pancreatic metastases is as follows:

3.
Good condition and
Follow-up CT after four courses of chemotherapy showed that the lesions in the lung, pancreas and left chest wall were obviously shrunken. However, the patient's lung lesions developed later and eventually died of respiratory failure. The total survival time is 9 months.

Conclusion
We herein reported a case of pancreatic metastases from small cell carcinoma of the lung with abdominal symptoms and slightly elevated serum CA19-9 levels. The possibility of other rare tumors should be considered in patients with multiple systemic metastases but were in good general condition. Pathology and immunohistochemistry should adequately used by considering such situations.

Ethics Approval and Consent to Participate
The study protocol was approved by the Ethics Committees of the people's hospital of Suichang county, and all participants provided written informed consent.

Consent for Publication
Not applicable.

Availability of Data and Materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Competing Interests
All authors declare that they have no any conflict of interests.

Funding
The study supported by the Zhejiang Medical and Health Science and Technology Plan Project (No. 2019KY396). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript Author's Contribution WH W and YL T collected information and drafted the manuscript. All authors read and approved the final manuscript.