Complete remission of recurrent multiple insulin-producing neuroendocrine tumors of the pancreas with somatostatin analogs: a case report and literature review.

Hyperinsulinemic hypoglycemia is most commonly caused by a single, sporadic insulinoma. Multicentric insulinoma disease (insulinomatosis) as well as metachronous neuroendocrine tumors of the pancreas, known also as neuroendocrine adenomatosis, represent a very rare condition, if not associated with multiple endocrine neoplasia type 1 syndrome (MEN1) or Von Hippel Lindau disease. We report a 9-year follow-up of a 41-year-old woman, initially presenting with hypoglycemic syndrome caused by two insulin-producing tumors, who underwent subtotal pancreasectomy in 2012, with histology compatible with multiple small neuroendocrine tumors. An approximately 1-cm insulin-producing tumor recurred at subsequent biochemical and radiological follow-up, and was cured with the somatostatin analog octreotide as a single treatment, until remission of symptoms and complete regression of the pancreatic lesion achieved after only 16 months of treatment. The possible mechanisms for these findings are discussed and the literature is briefly reviewed.

Multifocality in Sporadic Medullary Thyroid Carcinoma: An International Multicenter Study.

BACKGROUND: Current surgical standard of care in sporadic medullary thyroid carcinoma (sMTC) consists of a minimum of total thyroidectomy with central neck dissection. Some have suggested thyroid lobectomy with isthmusectomy and central neck dissection for patients with sMTC, given their lower frequency of bilateral disease, although this topic has not been thoroughly studied. This study assessed the prevalence of multifocality in sMTC via a large international multi-institutional retrospective review to quantify this prevalence, including the impact of geography, to assess more accurately the risks associated with alternative surgical approaches. METHODS: A retrospective chart review of sMTC patients from 11 institutions over 29 years (1983-2011) was undertaken. Data regarding focality, extent of disease, RET germline analysis plus family and clinical history for multiple endocrine neoplasia type 2 (MEN2), and demographic data were collected and analyzed. RESULTS: Patients from four continents and seven countries were included in the sample. Data for 313 patients with documented sMTC were collected. Of these, 81.2% were confirmed with negative RET germline testing, while the remaining 18.8% demonstrated a negative family history and no manifestations of MEN2 syndromes other than MTC. Bilateral disease was identified in 17/306 (5.6%) patients, while multifocal disease was noted in 50/312 (16.0%) sMTC patients. When only accounting for germline negative patients, these rates were not significantly different (5.6% and 17%, respectively). Among them, when disease was unifocal in the ipsilateral lobe and isthmus, bilateral disease was present in 6/212 (2.8%) cases. When disease was multifocal in the ipsilateral lobe or isthmus, then bilateral disease was present in 8/37 (21.6%) cases (p < 0.001). No geographic differences in focality were identified. CONCLUSIONS: The 5.6% prevalence of bilateral foci in sMTC suggests that total thyroidectomy should remain the standard of care for initial surgery, as less complete thyroid surgery may fail to address fully the primary site of disease. Whether ipsilateral tumor focality should be an independent factor determining the need for completion thyroidectomy when sMTC is diagnosed after hemithyroidectomy remains to be determined.

Circulating miRNA95 and miRNA190 are sensitive markers for the differential diagnosis of thyroid nodules in a Caucasian population.

CONTEXT: MicroRNA (miRNAs) are nonprotein-encoding RNAs that regulate gene expression and enable the distinction of benign from malignant tissues in human cancers. OBJECTIVE: We investigated the role of miRNA circulating in the blood for the differential diagnosis of thyroid nodules. SETTING AND DESIGN: miRNA profiling was assessed by TaqMan Array Human MicroRNA A Cards v2.0 in pooled sera from 12 healthy subjects (HS), 12 nodular goiters (NG), and 12 patients with papillary thyroid cancer (PTC) (cohort 1). From this analysis, we selected eight miRNAs that were validated in individual samples (same of cohort 1) by qRT-PCR. Four miRNAs were confirmed differentially expressed in PTC and were analyzed in a larger second cohort. RESULTS: The profiling analysis revealed eight miRNAs (miRNA579, -95, -29b, 5-01-3p, -548d-5p down-regulated, and miR190, -362-3p, -518a-5p up-regulated) which differ in PTC compared with NG and HS. After the validation in individual samples, we confirmed as differentially expressed miRNA579, -95, -29b, and miRNA190. These miRNAs were further validated in a second cohort of sera from 79 PTC, 80 NG, and 41 HS. MiRNA95 had a sensitivity of 94.9%, which reached 100% in a multivariate risk model combined with miRNA190. We developed a mathematical formula that calculates the probability of malignancy with a cut-off value of 0.5 above which the patient was at high risk of malignancy. CONCLUSIONS: We have identified for the first time two miRNAs differently expressed in serum of PTC patients who in combination allow the differential diagnosis of thyroid nodules with great accuracy in our study population. Additional studies are required; however, to define whether these results will also be generalized across other patient populations."

Fine needle aspiration and medullary thyroid carcinoma: the risk of inadequate preoperative evaluation and initial surgery when relying upon FNAB cytology alone.

OBJECTIVES: To evaluate the diagnostic accuracy of fine-needle aspiration biopsy (FNAB) to preoperatively diagnose medullary thyroid cancer (MTC) among multiple international centers and evaluate how the cytological diagnosis alone could impact patient management. METHODS: We performed a retrospective chart review of sporadic MTC (sMTC) patients from 12 institutions over the last 29 years. FNAB cytology results were compared to final pathologic diagnoses to calculate FNAB sensitivity. To evaluate the impact of cytology sensitivity for MTC according to current practice and to avoid confounding results by local treatment protocols, changes in treatment patterns over time, and the influence of ancillary findings (e.g., serum calcitonin), therapeutic interventions based on FNAB cytology alone were projected into 1 of 4 treatment categories: total thyroidectomy (TT) and central neck dissection (CND), TT without CND, diagnostic hemithyroidectomy, or observation. RESULTS: A total of 313 patients from 4 continents and 7 countries were included, 245 of whom underwent FNAB. FNAB cytology revealed MTC in 43.7% and possible MTC in an additional 2.4%. A total of 113 (46.1%) patients with surgical pathology revealing sMTC had FNAB findings that supported TT with CND, while 37 (15.1%) supported TT alone. In the remaining cases, diagnostic hemithyroidectomy and observation were projected in 32.7% and 6.1%, respectively. CONCLUSION: FNAB is an important diagnostic tool in the evaluation of thyroid nodules, but the low sensitivity of cytological evaluation alone in sMTC limits its ability to command an optimal preoperative evaluation and initial surgery in over half of affected patients.

Telomere length in neoplastic and nonneoplastic tissues of patients with familial and sporadic papillary thyroid cancer.

INTRODUCTION: Many studies have found an association between altered telomere length (TL), both attrition or elongation, and cancer phenotype. Recently, we have reported that patients with the familial form of papillary thyroid cancer (FPTC) have short telomeres in blood leucocytes. AIM: To evaluate relative TL (RTL) at somatic level in neoplastic and nonneoplastic tissues of patients with FPTC (n = 30) and sporadic PTC (n = 46). METHODS: RTL was measured by quantitative PCR in neoplastic thyroid tissues, in the corresponding nontumor thyroid tissues (normal contralateral thyroid), and in other extrathyroidal tissues (lymph nodes, muscles, or buccal mucosa). RTL was also measured in adenomas and hyperplastic nodules. In a subset of samples, telomerase expression was measured by quantitative PCR. RESULTS: Mean ± SD RTL of FPTC patients was short in neoplastic thyroid tissues (0.87 ± 0.2) with no difference from the normal contralateral thyroid tissues (0.85 ± 0.11) and extrathyroidal tissues (0.85 ± 0.31). On the contrary, in patients with sporadic PTC, the mean ± SD RTL in the neoplastic tissues (1.73 ± 0.63) was significantly shorter than that found in normal contralateral tissues (2.58 ± 0.89) and extrathyroidal tissues (2.5 ± 0.86). For all tissue samples (cancer, normal thyroid, and nonthyroidal tissues) the mean ± SD RTL of familial cases was shorter (P < 0.0001) than that found in tissues from sporadic PTC. RTL of FPTC was also lower (P < 0.0001) than that of 23 follicular adenomas (1.6 ± 0.7) and 24 hyperplastic nodules (2.2 ± 0.9). CONCLUSIONS: Our results demonstrate that short telomeres are a consistent feature of PTC, which in familial cases, is not restricted to the tumor tissue. This finding suggests that FPTC has a distinct, heritable, genetic background.

Impact of proto-oncogene mutation detection in cytological specimens from thyroid nodules improves the diagnostic accuracy of cytology.

CONTEXT: Fine-needle aspiration cytology (FNAC) is the gold standard for the differential diagnosis of thyroid nodules but has the limitation of inadequate sampling or indeterminate lesions. OBJECTIVE: We aimed to verify whether search of thyroid cancer-associated protooncogene mutations in cytological samples may improve the diagnostic accuracy of FNAC. STUDY DESIGN: One hundred seventy-four consecutive patients undergoing thyroid surgery were submitted to FNAC (on 235 thyroid nodules) that was used for cytology and molecular analysis of BRAF, RAS, RET, TRK, and PPRgamma mutations. At surgery these nodules were sampled to perform the same molecular testing. RESULTS: Mutations were found in 67 of 235 (28.5%) cytological samples. Of the 67 mutated samples, 23 (34.3%) were mutated by RAS, 33 (49.3%) by BRAF, and 11 (16.4%) by RET/PTC. In 88.2% of the cases, the mutation was confirmed in tissue sample. The presence of mutations at cytology was associated with cancer 91.1% of the times and follicular adenoma 8.9% of the time. BRAF or RET/PTC mutations were always associated with cancer, whereas RAS mutations were mainly associated with cancer (74%) but also follicular adenoma (26%). The diagnostic performance of molecular analysis was superior to that of traditional cytology, with better sensitivity and specificity, and the combination of the two techniques further contributed to improve the total accuracy (93.2%), compared with molecular analysis (90.2%) or traditional cytology (83.0%). CONCLUSIONS: Our findings demonstrate that molecular analysis of cytological specimens is feasible and that its results in combination with cytology improves the diagnostic performance of traditional cytology.