An increased calcitonin serum level is suggestive of a medullary thyroid cancer (MTC), but is not pathognomonic. The possibility of false positives or other calcitonin-secreting neuroendocrine neoplasms (NENs) should be considered. Serum calcitonin levels are generally assessed by immunoradiometric and chemiluminescent assays with high sensitivity and specificity; however, slightly moderately elevated levels could be attributable to various confounding factors. Calcitonin values >100 pg/mL are strongly suspicious of malignancy, whereas in patients with moderately elevated values (10–100 pg/mL) a stimulation test may be applied to improve diagnostic accuracy. Although the standard protocol and the best gender-specific cut-offs for calcium-stimulated calcitonin are still controversial, the fold of the calcitonin increase after stimulation seems to be more reliable. Patients with MTC show stimulated calcitonin values at least three to four times higher than the basal values, whereas calcitonin-secreting NENs can be distinguished from a C-cell disease by the absence of or <two-fold response to stimulation. The measurement of calcitonin in fine-needle aspirate washout (FNA-CT) and calcitonin immunocytochemical staining from thyroid nodules are ancillary methods that may significantly improve MTC diagnosis. The present review examines the gray areas in the interpretation of calcitonin measurement in order to provide a tool to clarify the origin of calcitonin secretion and differentiate the behavior of the two-faced Janus of neuroendocrinology: intra-thyroid (MTC) and extra-th9yroid NENs.
Elisa Giannetta, Valentina Guarnotta, Barbara Altieri, Concetta Sciammarella, Elia Guadagno, Pasqualino Malandrino, Giulia Puliani, Tiziana Feola, Andrea M Isidori, Annamaria Anita Livia Colao, and Antongiulio Faggiano
Alessia Cozzolino, Tiziana Feola, Ilaria Simonelli, Giulia Puliani, Valeria Hasenmajer, Marianna Minnetti, Elisa Giannetta, Daniele Gianfrilli, Patrizio Pasqualetti, Andrea Lenzi, and Andrea M Isidori
Neurosurgery is the first-line treatment for acromegaly. Whether metabolic disorders are reversible after neurosurgery is still debated. The meta-analysis aimed to address the following questions: (i) Does neurosurgery affect glycolipid metabolism? (ii) Are these effects related to disease control or follow-up length?
A meta-analysis and systematic review of the literature.
Three reviewers searched databases until August 2019 for prospective trials reporting glycometabolic outcomes after neurosurgery. Three other extracted outcomes, all assessed the risk of bias.
Twenty studies were included. Neurosurgery significantly reduced fasting plasma glucose (FPG) (effect size (ES): −0.57 mmol/L, 95% CI: −0.82 to −0.31; P < 0.001), glucose load (ES: −1.10 mmol/L, 95% CI: −1.66 to −0.53; P < 0.001), glycosylated haemoglobin (HbA1c) (ES: −0.28%, 95% CI: −0.42 to −0.14; P < 0.001), fasting plasma insulin (FPI) (ES: −10.53 mU/L, 95% CI: −14.54 to −6.51; P < 0.001), homeostatic model assessment of insulin resistance (HOMA-IR) (ES: −1.98, 95% CI: −3.24 to −0.72; P = 0.002), triglycerides (TGDs) (ES: −0.28 mmol/L, 95% CI: −0.36 to −0.20; P < 0.001) and LDL-cholesterol (LDLC) (ES: −0.23 mmol/L, 95% CI: −0.45 to −0.02 mmol/L); P = 0.030) and increased HDL-cholesterol (HDLC) (ES: 0.21 mmol/L, 95% CI: 0.14 to 0.28; P < 0.001). Meta-regression analysis showed that follow-up length – not disease control – had a significant effect on FPG, with the greatest reduction in the shortest follow-up (beta = 0.012, s.e. = 0.003; P = 0.001).
Neurosurgery improves metabolism with a significant decrease in FPG, glucose load, HbA1c, FPI, HOMA-IR, TGDs, and LDLC and increase in HDLC. The effect on FPG seems to be more related to follow-up length than to disease control.