Synchronous neuroendocrine tumors in both the pancreas and ileum: A case report

Metachronous double primary neuroendocrine tumors in larynx and lung: a case report

When a patient harbors two or more neuroendocrine tumors (NETs), it can be difficult to determine whether they are double primary tumors or metastases. A 60-year-old man complained of voice change lasting 1 month. On physical examination and imaging, a 1.8-cm mass was observed in his epiglottis, and a laser epiglottectomy was performed. Upon microscopic examination, the tumor consisted of medium-sized ovoid or short spindle cells. Immunohistochemical staining of the tumor cells was positive for synaptophysin, chromogranin, and calcitonin but negative for CD56; the Ki-67 proliferation index was approximately 5%. The patient was diagnosed with atypical carcinoid tumor. In 2015, a hypermetabolic endobronchial tumor was identified in the left lower lobe by positron emission tomography-computed tomography. Bronchoscopic biopsy revealed palisading large tumor cells with high nuclear-cytoplasmic ratio, frequent mitoses, and necrosis. The tumor cells were positive for CD56 and negative for cytokeratin-7, thyroid transcription factor-1, P40, synaptophysin, chromogranin, and calcitonin; the Ki-67 proliferation index was approximately 90%. Overall histologic findings were consistent with large cell neuroendocrine carcinoma rather than metastatic atypical carcinoid tumor. Detailed clinical and pathological review are essential to differentiate between metastatic NET and double primary NETs and, therefore, to provide the best management of the patient.

Neuroendocrine neoplasms of gastrointestinal tract and secondary primary synchronous tumors: A systematic review of case reports. Casualty or causality?

BACKGROUND

Neuroendocrine neoplasms (NENs) can arise in most of the epithelial organs of the body and are not a rare condition in the gastrointestinal tract (GIT). The presence of NENs in GIT associated with other secondary primary malignancies (SPM) has been considered an exotic event. This study aims to describe the case reports of NENs accompanied by synchronous primary tumors.

METHODS AND FINDINGS

We performed a systematic literature search of the databases Scopus, PubMed, Scielo and LILACS to identify case reports that described the presence of NENs in GIT with SPM. 78 case reports were included. The mean of age of the cases was 60.2 years. 60% were male. 95.4% were NENs G1. 17 cases of NENs had metastasis. 80% of SPM were recognized in the GIT (36% in stomach, 27% in large intestine, 11.2% in small intestine, and 5.6% in esophagus). The most common type of SPM was adenocarcinoma (49.4%), followed by GIST (13.5%), other NENs in different GIT segment (7.9%), lymphoma (6.8%), and squamous cell carcinoma (4.5%). The most common tumor in GIT was adenocarcinoma (97.6%) and the presence of adenocarcinoma in the same segment of GIT was found in 68.4% of the cases. Association between adenocarcinomas and NENs in GIT (p:<0.0001) and adenocarcinoma and tumor in the same segment of GIT location were observed (p<0.001).

CONCLUSION

These results demonstrate that NENs with SPM are not a rare condition. Several theories have been proposed to explain this association; one of these is the ability of NENs to generate synchronous tumors by autocrine and paracrine effect. We observed an association between adenocarcinomas and NENs in the same segment of GIT.

The Pancreas as a Site of Metastasis or Second Primary in Patients with Small Bowel Neuroendocrine Tumors

BACKGROUND

The small bowel and pancreas are the most common primary sites of neuroendocrine tumors (NETs) giving rise to metastatic disease. Some patients with small bowel NETs (SBNETs) present with synchronous or metachronous pancreatic NETs (PNETs), and it is unclear whether these are separate primaries or metastases from one site to the other.

METHODS

A surgical NET database including patients undergoing operations for SBNETs or PNETs was reviewed. Patients with synchronous or metachronous tumors in both the small bowel and pancreas were identified, and available tissues from primary tumors and metastases were examined using a 4-gene quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC) panel developed for evaluating NETs of unknown primary.

RESULTS

Of 338 patients undergoing exploration, 11 had NETs in both the small bowel and pancreas. Tissues from 11 small bowel tumors, 9 pancreatic tumors, and 10 metastases were analyzed. qPCR and IHC data revealed that three patients had separate SBNET and PNET primaries, and five patients had SBNETs that metastasized to the pancreas. Pancreatic tissue was unavailable in two patients, and qPCR and IHC gave discrepant results in one patient.

CONCLUSIONS

NETs in both the small bowel and pancreas were found in 3% of our patients. In nearly two-thirds of evaluable patients, the pancreatic tumor was a metastasis from the SBNET primary, while in the remaining one-third of patients it represented a separate primary. Determining the origin of these tumors can help guide the choice of systemic therapy and surgical management.