Endocrine Abstracts

Introduction: Diagnosis of NETs (neuroendocrine tumors) is based on clinical manifestations, peptide and amine secretion, specialized radiological and nuclear imaging, secured by detailed histology and immunohistochemistry, which should be obtained whenever possible. Biomarkers are still the mainstay in the diagnosis and follow-up of patients with NETs.

Case report: We present the case of a 36-year-old patient with no significant pathological personal history, diagnosticated in 2015 with amesenteric tumor/jejunal GIST (gastrointestinal stromal tumor) and lymphadenopathies adjacent to the II–III jejunal branches. Surgery was performed, with good postoperative evolution. The histopathological exam shows malignant proliferation with solid and cordial architecture, areas of intratumoral necrosis and multiple images of vascular invasion; five lymph nodes present tumor metastasis. Immunohistochemistry assays decelerate synaptophysin, CD99 positive in most tumor cells, rare positive NSE and negative cromogranin; Ki67 positive in 10% of tumor cells. The final diagnosis was neuroendocrine tumor (NET G2). The patient met the criteria for inclusion in somatostatin analog therapy, but it was schedule on demand. Between 2016 and October 2017: chromogranin A, serotonin and 5-hydroxy indolacetate were negative, no recidives on CT scan. In November 2017, the patient was admitted for weight loss, abdominal pain, nausea. Biologically, the carcinoembryonic antigen was over the upper limit, with anemia and important inflammatory syndrome. CT scan describes adenopathies in the left flank, with central necrosis and tendency to confluence, and three new hepatic nodular lesions, suspected of secondary dissemination. Surgically reintervention with the excision of the hepatic formations and the lymph node was performed; immunohistochemistry detects synaptophysin, CD56, NSE positive in the hepatic lesions with negative cromogranin; negative synaptophysin, cromogranin and CD99, with positive CD56, NSE in lymph nodes and Ki67 20% in both sites. SSTR2 and SSTR5 receptors were also positive. A Tektrotyd (Technetium 99mTc-HYNIC-Tyr3-Octreotide) scan confirmed the presence of the radiopharmaceutical pathological capture in the hepatic VI and III segment, grade Krenning 3, with a limited tumor dissemination score. Considering the aggressive progression of the disease, the dissemination rate, the Ki67 increase from 10% to 20% in a short time, we opt for somatostatin therapy and PRRT treatment initiation, the patient fulfilling the inclusion criteria (Krenning score> 2).

Conclusions: The diagnosis delay, the trap of negative usual neuroendocrine markers and the refusing of the specific treatment, lead to unfavorable disease progression, aggressive growth of Ki67, which together can lead to therapeutic failure.

Keyword: neuroendocrine tumor, negative markers, Ki67