Endocrine Abstracts

Introduction: Chromogranin A continues to be one of the most valuable markers for neuroendocrine tumors (NETs) however, it has several limitations, including its reduced specificity.

Methods: The authors present the case of a patient diagnosed with a midgut NET, during follow-up.

Results: Male patient, 61 years old, with chronic renal disease (CRD), underwent right hemicolectomy owing to ileo-cecal valve lesion; histological result consistent with NET. Pre-operatory staging: without metastatic disease on thoracic-abdominal CT; octreoscan with elevated expression of somatostatin receptors on ileo-cecal valve topography; CgA 32 nmol/l (<6.0), NSE 14 ng/ml (<15.0). Anatomopathological examination of surgical specimen: well-differentiated G1 NET; mesenteric infiltration and metastization in 1 of 20 lymph nodes (T3N1Mx; AJCC-IIB; R0). After 3 years of stable disease, the patient presented CgA of 1173.8 ng/ml (<85), with impaired CRD (Cr 4.42 mg/dl), on dyalisis. 3 months later: CgA 1619.0 pg/ml and Calcitonin 26 pg/ml (<10). In additional investigation, cervical-thoracic-abdominal CT and 68 Ga-PET rated negative for relapse. Total colonoscopy, including evaluation of ileocolonic anastomosis, didn’t demonstrate alterations. The patient maintained follow-up with clinical stability, showing in the last evaluation CgA 272.3 ng/ml, Calcitonin 38 pg/ml, NSE 12 ng/ml (<15) and Cr 6.88 mg/dl.

Conclusions: Evaluation of CgA in end stage renal disease is not reliable. Although it’s postulated that higher the degree of renal failure, higher the CgA concentration, it wasn’t verified such correlation. In NET patients, renal function should be carefully evaluated and ruled out the potential impact on the concentration of CgA.