Pituitary incidentaloma : An Endocrine Society Clinical Practice Guideline

in Journal of Clinical Endocrinology and Metabolism (2011)

Clinical Characteristics and Therapeutic Responses in Patients with Germ-Line AIP Mutations and Pituitary Adenomas - An International Collaborative Study

in Journal of Clinical Endocrinology and Metabolism (2010), 95(11),

Context: AIP mutations (AIPmut) give rise to a pituitary adenoma predisposition that occurs in familial isolated pituitary adenomas and less often in sporadic cases. The clinical and therapeutic features ... [more ▼]

Context: AIP mutations (AIPmut) give rise to a pituitary adenoma predisposition that occurs in familial isolated pituitary adenomas and less often in sporadic cases. The clinical and therapeutic features of AIPmut-associated pituitary adenomas have not been studied comprehensively. Objective: The objective of the study was to assess clinical/therapeutic characteristics of AIPmut pituitary adenomas. Design: This study was an international, multicenter, retrospective case collection/database analysis. Setting: The study was conducted at 36 tertiary referral endocrine and clinical genetics departments. Patients: Patients included 96 patients with germline AIPmut and pituitary adenomas and 232 matched AIPmut-negative acromegaly controls. Results: The AIPmut population was predominantly young and male (63.5%); first symptoms occurred as children/adolescents in 50%. At diagnosis, most tumors were macroadenomas (93.3%); extension and invasion was common. Somatotropinomas comprised 78.1% of the cohort; there were also prolactinomas (n = 13), nonsecreting adenomas (n = 7), and a TSH-secreting adenoma. AIPmut somatotropinomas were larger (P = 0.00026), with higher GH levels (P = 0.00068), more frequent extension (P = 0.018) and prolactin cosecretion (P = 0.00023), and occurred 2 decades before controls (P < 0.000001). Gigantism was more common in the AIPmut group (P < 0.000001). AIPmut somatotropinoma patients underwent more surgical interventions (P = 0.00069) and had lower decreases in GH (P = 0.00037) and IGF-I (P = 0.028) and less tumor shrinkage with somatostatin analogs (P < 0.00001) vs. controls. AIPmut prolactinomas occurred generally in young males and frequently required surgery or radiotherapy. Conclusions: AIPmut pituitary adenomas have clinical features that may negatively impact treatment efficacy. Predisposition for aggressive disease in young patients, often in a familial setting, suggests that earlier diagnosis of AIPmut pituitary adenomas may have clinical utility. [less ▲]

TAC3 and TACR3 defects cause hypothalamic congenital hypogonadotropic hypogonadism in humans.

in Journal of Clinical Endocrinology and Metabolism (2010), 95(5), 2287-95

CONTEXT: Missense loss-of-function mutations in TAC3 and TACR3, the genes encoding neurokinin B and its receptor NK3R, respectively, were recently discovered in kindreds with nonsyndromic normosmic ... [more ▼]

CONTEXT: Missense loss-of-function mutations in TAC3 and TACR3, the genes encoding neurokinin B and its receptor NK3R, respectively, were recently discovered in kindreds with nonsyndromic normosmic congenital hypogonadotropic hypogonadism (CHH), thus identifying a fundamental role of this pathway in the human gonadotrope axis. OBJECTIVE: The objective of the study was to investigate the consequences on gonadotrope axis of TAC3 deletion and TACR3 truncation in adult patients with normosmic complete CHH. RESULTS: We identified three unrelated patients with the same homozygous substitution in the TAC3 intron 3 acceptor splicing site (c.209-1G>C) and three siblings who bore a homozygous mutation in the TACR3 intron 2 acceptor splicing site (c.738-1G>A). We demonstrated that these two mutations, respectively, deleted neurokinin B and truncated its receptor NK3R. We found in three patients with TAC3 mutation originating from Congo and Haiti a founding event in a more distant ancestor by means of haplotype analysis. We calculated that time to this common ancestor was approximately 21 generations. In several patients we observed a dissociation between the very low LH and normal or nearly normal FSH levels, this gonadotropin responding excessively to the GnRH challenge test. This particular hormonal profile, suggests the possibility of a specific neuroendocrine impairment in patients with alteration of neurokinin B signaling. Finally, in these patients, pulsatile GnRH administration normalized circulating sex steroids, LH release, and restored fertility in one subject. CONCLUSION: Our data demonstrate the hypothalamic origin of the gonadotropin deficiency in these genetic forms of normosmic CHH. Neurokinin B and NK3R therefore both play a crucial role in hypothalamic GnRH release in humans. [less ▲]

Pioglitazone Use in Combination with Insulin in the Prospective Pioglitazone Clinical Trial in Macrovascular Events Study (PROactive19).

in Journal of Clinical Endocrinology and Metabolism (2010)

Objective: In this post hoc analysis, we examined insulin requirements and regimens, glycemic control, cardiovascular outcomes, and safety in the patients treated with insulin at baseline in the ... [more ▼]

Objective: In this post hoc analysis, we examined insulin requirements and regimens, glycemic control, cardiovascular outcomes, and safety in the patients treated with insulin at baseline in the Prospective Pioglitazone Clinical Trial in Macrovascular Events study. Design: The Prospective Pioglitazone Clinical Trial in Macrovascular Events study was a double-blind, placebo-controlled outcome study (mean follow-up 34.5 months) in 5238 high-risk patients with type 2 diabetes randomized to pioglitazone (force titrated to 45 mg) or placebo. One third of the total population (pioglitazone 864; placebo 896) were receiving insulin at baseline. Results: A rapid and sustained decrease in insulin dose was observed with pioglitazone vs. a progressive increase with placebo. By study end, the mean insulin dose was lower with pioglitazone (42 vs. 55 U/d with placebo; P < 0.0001). The insulin regimen (number on insulin, need for multiple injections, and reduction in oral agents) had been simplified vs. placebo; nevertheless, a greater glycosylated hemoglobin reduction was observed with pioglitazone (-0.93%) vs. placebo (-0.45%; P < 0.0001). At the final visit, insulin had been discontinued in 9% of pioglitazone vs. 2% of placebo patients (P < 0.0001). More insulin-resistant patients (defined as poorly controlled type 2 diabetes despite high doses of insulin) in the pioglitazone plus insulin group showed the greatest glycosylated hemoglobin decline. There were nonsignificant reductions with pioglitazone relative to placebo in the cardiovascular primary (hazard ratio 0.86; 95% confidence interval 0.71, 1.04; P = 0.1198) and main secondary (hazard ratio 0.85; 95% confidence interval 0.67, 1.08; P = 0.1831) end points in insulin-treated patients. The rates of overall heart failure, edema, and hypoglycemia were higher with pioglitazone [13.5 vs 10.5% (P = 0.0489); 30.8 vs. 18.2% (P < 0.0001); and 42.1 vs 29.0% (P < 0.0001), respectively], but there were no significant differences in serious events. Conclusions: Pioglitazone use in combination with insulin resulted in a sustained improved glycemic control and allowed the treatment regimens to be simplified and the insulin doses reduced. [less ▲]

A coherent organization of differentiation proteins is required to maintain an appropriate thyroid function in the Pendred thyroid.

in Journal of Clinical Endocrinology and Metabolism (2010), 95(8), 4021-30

CONTEXT: Pendred syndrome is caused by mutations in the gene coding for pendrin, an apical Cl-/I- exchanger. OBJECTIVE: To analyze intrathyroidal compensatory mechanisms when pendrin is lacking, we ... [more ▼]

CONTEXT: Pendred syndrome is caused by mutations in the gene coding for pendrin, an apical Cl-/I- exchanger. OBJECTIVE: To analyze intrathyroidal compensatory mechanisms when pendrin is lacking, we investigated the thyroid of a patient with Pendred syndrome. The expression of proteins involved in thyroid hormone synthesis, markers of oxidative stress (OS), cell proliferation, apoptosis, and antioxidant enzymes were analyzed. RESULTS: Three morphological zones were identified: nearly normal follicles with iodine-rich thyroglobulin in the colloid (zone 1.a), small follicles without iodine-rich thyroglobulin in lumina (zone 1.b), and destroyed follicles (zone 2). In zones 1.a, dual oxidase (Duox) and thyroid peroxidase (TPO) were localized at the apical pole, OS and cell apoptosis were absent, but ClC-5 expression was strongly increased. In zones 1.b, Duox and TPO were aberrantly present and increased in the cytosol and associated with high OS, apoptosis, cell proliferation, and increased expression of peroxiredoxin-5, catalase, and dehalogenase-1 but moderate ClC-5 expression. CONCLUSION: In conclusion, the absence of pendrin is accompanied by increased ClC-5 expression that may transiently compensate for apical iodide efflux. In more affected follicles, Duox and TPO are relocated in the cytosol, leading to abnormal intracellular thyroid hormone synthesis, which results in cell destruction presumably because intracellular OS cannot be buffered by antioxidant defenses. [less ▲]

Chorionic Gonadotropin Stimulation of Angiogenesis and Pericyte Recruitment

in Journal of Clinical Endocrinology and Metabolism (2009), 94(11), 4567-74

During the periimplantation period, human chorionic gonadotropin (hCG) plays a key role by increasing the uterine blood flow through uterine vessel vasodilatation but also through angiogenesis. Indeed, we ... [more ▼]

During the periimplantation period, human chorionic gonadotropin (hCG) plays a key role by increasing the uterine blood flow through uterine vessel vasodilatation but also through angiogenesis. Indeed, we previously demonstrated that hCG contributes to endothelial cell recruitment and vessel formation. OBJECTIVE: In this study, hCG was proposed as an arteriogenic factor that could promote perivascular cell recruitment and vessel stabilization. DESIGN: The aortic ring assay, a three-dimensional ex vivo angiogenesis system mimicking all the steps of the angiogenesis process was used to study the impact of hCG on pericyte recruitment and vessel maturation. SETTING: The study was conducted at a university hospital laboratory. MAIN OUTCOME MEASURES: Perivascular cell proliferation, migration, and apposition were quantified by computerized image analysis. RESULTS: Physiological concentrations of hCG (10-400 IU/ml) significantly enhanced pericyte sprouting and migration and gave rise to the maturation and coverage of endothelial capillaries. In a three-dimensional coculture model of endothelial and perivascular cells, hCG enhanced vessel tube formation and endothelial/mural cell adhesion. In addition, hCG stimulated the proliferation of human umbilical vein endothelial cells and smooth muscle cells. The specificity of these effects was determined by using an anti-hCG blocking antibody. Signaling pathways implicated on this hCG effect is protein kinase A and phospholipase C/protein kinase C dependent for the proliferative effect but only phospholipase C/protein kinase C for the migrative process. CONCLUSIONS: Our findings highlight a novel paracrine role of this early embryonic signal in vessel maturation by stimulating perivascular cell recruitment, migration, and proliferation. [less ▲]

Persistence of an intact endometrial matrix and vessels structure in women exposed to VA-2914, a selective progesterone receptor modulator.

in Journal of Clinical Endocrinology and Metabolism (2008), 93(11), 4525-31

Background: VA-2914 is a selective progesterone receptor modulator with potential contraceptive activity that induces amenorrhea, whereas progestins cause endometrial spotting and bleeding. This abnormal ... [more ▼]

Background: VA-2914 is a selective progesterone receptor modulator with potential contraceptive activity that induces amenorrhea, whereas progestins cause endometrial spotting and bleeding. This abnormal bleeding due to progestins is a consequence of focal stromal proteolysis by an increase in naked vessel size and density. Objective: Our objective was to quantify the effects of VA-2914 on endometrial vascularization, fibrillar matrix, and vascular endothelial growth factor (VEGF)-A expression in endometrial biopsies from 41 women before and after 12 wk daily treatment with a placebo, or 2.5, 5, or 10 mg VA-2914. Methods: Collagen fibrillar network was stained by silver impregnation. Vessel area, density, and structure were quantified with a computer-assisted image analysis system after double immunostaining using an anti-von Willebrand factor (endothelial cells) and an anti- smooth muscle actin (vascular smooth muscle cells) marker antibody. VEGF-A mRNAs were quantified by RT-PCR and localized by immunohistochemistry. Results: The endometrial vessels, collagen network, and mRNA levels of VEGF-A were identical during the luteal phase at baseline and in VA-2914 treated women. VEGF-A distribution was unchanged. Conclusions: VA-2914 does not alter the endometrial matrix and cells, and does not modify the endometrial vessel morphology as compared with baseline biopsies. [less ▲]

Relationship between bone mineral density changes and fracture risk reduction in patients treated with strontium ranelate

in Journal of Clinical Endocrinology and Metabolism (2007), 92(8), 3076-3081

Objective: Our objective was to analyze the relationship between bone mineral density (BMD) changes and fracture incidence during 3-yr treatment with strontium ranelate. Patients: Women from the strontium ... [more ▼]

Objective: Our objective was to analyze the relationship between bone mineral density (BMD) changes and fracture incidence during 3-yr treatment with strontium ranelate. Patients: Women from the strontium ranelate arm of the Spinal Osteoporosis Therapeutic Intervention study and the TReatment Of Peripheral OSteoporosis study were evaluated. Outcome Measures: The outcome measures included BMD at the lumbar spine, femoral neck, and total proximal femur assessed at baseline and after a follow-up of 1 and 3 yr; semiquantitative visual assessment of vertebral fractures; and nonvertebral fractures based on written documentation. Results: After 3 yr of strontium ranelate treatment, each percentage point increase in femoral neck and total proximal femur BMD was associated with a 3%(95% adjusted confidence interval, 1-5%) and2% (1-4%) reduction in risk of a new vertebral fracture, respectively. The 3- yr changes in femoral neck and total proximal femur BMD explained 76% and 74%, respectively, of the reduction in vertebral fractures observed during the treatment. Three-year changes in spine BMD were not statistically associated with the incidence of new vertebral fracture (P = 0.10). No significant associations were found between 3- yr changes in BMD and incidence of new nonvertebral fractures, but a trend was found for femoral neck BMD (P = 0.09) and for total proximal femur BMD (P = 0.07). An increase in femoral neck BMD after 1 yr was significantly associated with the reduction in incidence of new vertebral fractures observed after 3 yr (P = 0.04). Conclusion: During 3-yr strontium ranelate treatment, an increase in femoral neck BMD was associated with a proportional reduction in vertebral fracture incidence. [less ▲]

Mutations in the aryl hydrocarbon receptor interacting protein gene are not highly prevalent among subjects with sporadic pituitary adenomas.

in Journal of Clinical Endocrinology and Metabolism (2007), 92(5), 1952-5

CONTEXT: Limited screening suggests that three germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene are not involved in sporadic pituitary tumorigenesis. Multiple novel ... [more ▼]

CONTEXT: Limited screening suggests that three germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene are not involved in sporadic pituitary tumorigenesis. Multiple novel mutations of this gene have since been identified in familial isolated pituitary adenoma cohorts. OBJECTIVE: The objective of the study was to undertake full AIP coding sequence screening to assess for the presence of germline and somatic mutations in European Union subjects with sporadic pituitary tumors. DESIGN: The study design was the analysis of DNA from peripheral blood lymphocytes and analysis of exons 1-6 and paraexonic intron sequences of AIP. Multiplex ligation-dependent probe amplification was used to screen separate sporadic pituitary tumor tissue samples for discrete and extensive deletions or mutations of the AIP gene. Setting: The study was conducted in university tertiary referral Clinical Genetics, Molecular Biology, and Endocrinology Departments. RESULTS: In 107 patients [prolactinomas (n =49), nonfunctioning tumors (n = 29), somatotropinomas (n = 26), ACTH-secreting tumors (n = 2), TSH-secreting tumors (n = 1)], no germline mutations of AIP were demonstrated. Among a group of 41 tumor samples from other subjects, a novel AIP mutation (R22X) was found in one sample in which the corresponding allele was deleted; follow-up screening of the patient demonstrated a germline R22X AIP mutation. CONCLUSIONS: AIP mutations do not appear to play a prominent role in sporadic pituitary tumorigenesis in this population of European subjects. [less ▲]

Clinical characterization of familial isolated pituitary adenomas.

in Journal of Clinical Endocrinology and Metabolism (2006), 91(9), 3316-23

CONTEXT: Familial pituitary adenomas occur rarely in the absence of multiple endocrine neoplasia type 1 (MEN1) and Carney complex (CNC). OBJECTIVE: Our objective was to characterize the clinical and ... [more ▼]

CONTEXT: Familial pituitary adenomas occur rarely in the absence of multiple endocrine neoplasia type 1 (MEN1) and Carney complex (CNC). OBJECTIVE: Our objective was to characterize the clinical and genealogical features of non-MEN1/CNC familial isolated pituitary adenomas (FIPA). DESIGN AND SETTING: We conducted a retrospective study of clinical and genealogical characteristics of FIPA cases and performed a comparison with a sporadic population at 22 university hospitals in Belgium, Italy, France, and The Netherlands. RESULTS: Sixty-four FIPA families including 138 affected individuals were identified [55 prolactinomas, 47 somatotropinomas, 28 nonsecreting adenomas (NS), and eight ACTH-secreting tumors]. Cases were MEN1/PRKAR1A-mutation negative. First-degree relationships predominated (75.6%) among affected individuals. A single tumor phenotype occurred in 30 families (homogeneous), and heterogeneous phenotypes occurred in 34 families. FIPA cases were younger at diagnosis than sporadic cases (P = 0.015); tumors were diagnosed earlier in the first vs. the second generation of multigenerational families. Macroadenomas were more frequent in heterogeneous vs. homogeneous FIPA families (P = 0.036). Prolactinomas from heterogeneous families were larger and had more frequent suprasellar extension (P = 0.004) than sporadic cases. Somatotropinomas occurred as isolated familial somatotropinoma cases and within heterogeneous FIPA families; isolated familial somatotropinoma cases represented 18% of FIPA cases and were younger at diagnosis than patients with sporadic somatotropinomas. Familial NS cases were younger at diagnosis (P = 0.03) and had more frequently invasive tumors (P = 0.024) than sporadic cases. CONCLUSIONS: Homogeneous and heterogeneous expression of prolactinomas, somatotropinomas, NS, and Cushing's disease can occur within families in the absence of MEN1/CNC. FIPA and sporadic cases have differing clinical characteristics. FIPA may represent a novel endocrine neoplasia classification that requires further genetic characterization. [less ▲]