Cushing's disease due to somatic USP8 mutations: a systematic review and meta-analysis.

PURPOSE: Cushing's disease (CD) is a severe illness generally caused by microcorticotropinomas (MICs) and in approximately 7-20% of patients by macrocorticotropinomas (MACs). USP8-mutations have been identified as a major genetic cause of CD (~ 50%). Few studies have reported the distribution between MICs-MACs related to USP8-mutations and their genotype-phenotype correlations. Therefore, we aimed to evaluate USP8-mutations in a cohort of MICs-MACs from a unique center and to perform a systematic review and meta-analysis. METHODS: DNA-tumor-tissues from 47 corticotropinomas (16 MICs and 31 MACs) were sequenced. Clinical-biochemical data, radiological imaging data and remission/recurrence rates were evaluated. In addition, we performed a meta-analysis of nine published series (n = 630). RESULTS: We identified four different USP8-mutations previously described, in 11 out of 47 (23.4%) corticotropinomas; 8 out of 11 were MACs. The urinary cortisol levels of our patients with corticotrophin USP8-mutated-alleles were lower than those of patients with wild-type (WT) alleles (p ≤ 0.017). The frequency of USP8-mutated-alleles among the series was approximately 30% with a higher prevalence in female-patients (p < 0.1 × 10-4). Among the 5 series, the remission rates were higher in patients with USP8-mutated-alleles than in those with the USP8-WT-alleles (p < 0.1 × 10-4). CONCLUSION: Our data, as well as the retrospective review of CD series associated with USP8-mutated alleles, show heterogeneous findings among the series. Several drawbacks included the lack of a systematic protocol to evaluate these patients before surgery and follow-up. Further prospective studies using a systematic protocol will provide more consistent information about the influence of the corticotropinomas with USP8-mutated alleles on the phenotype, responses to treatment and outcome of patients with CD.

Management of hypopituitarism: a perspective from the Brazilian Society of Endocrinology and Metabolism.

Hypopituitarism is a disorder characterized by insufficient secretion of one or more pituitary hormones. New etiologies of hypopituitarism have been recently described, including head trauma, cerebral hemorrhage, and drug-induced hypophysitis. The investigation of patients with these new disorders, in addition to advances in diagnosis and treatment of hypopituitarism, has increased the prevalence of this condition. Pituitary hormone deficiencies can induce significant clinical changes with consequent increased morbidity and mortality rates, while hormone replacement based on current guidelines protects these patients. In this review, we will first discuss the different etiologies of hypopituitarism and then address one by one the clinical aspects, diagnostic evaluation, and therapeutic options for deficiencies of TSH, ACTH, gonadotropin, and GH. Finally, we will detail the hormonal interactions that occur during replacement of pituitary hormones.

Management of pituitary incidentaloma.

Pituitary incidentalomas (PIs) represent a modern clinical entity increasingly recognized due to advances and easier accessibility to imaging techniques. By definition, PIs should be detected during brain imaging performed for investigation of a non-pituitary disease. Although anatomic variations, technical artefacts or pituitary hyperplasia might also be interpreted as PIs, the most relevant incidentally detected lesions are those that fulfill radiological criteria for a pituitary adenoma in asymptomatic patients or in the presence of subclinical diseases. The natural history of PIs is not fully determined, but there is a wealth of evidence indicating that most microincidentalomas (lesions < 10 mm) have a benign course, whereas macroincidentalomas (≥10 mm) deserve more attention due to an increased risk for hormone abnormalities and mass effects. This concept is important to keep in mind for an optimal diagnostic and therapeutic management of PIs that avoids harmful iatrogenesis and unnecessary health care costs.

Thymus hyperplasia after resolution of hypercortisolism in ACTH-dependent Cushing's syndrome: the importance of thymic vein catheterization.

Thymic hyperplasia has been described after the resolution of hypercortisolism from several etiologies, causing great diagnostic dilemmas. We describe a case where the catheterization of the thymic vein was essential for the differential diagnosis of a thymic enlargement in an adrenalectomized patient with ACTH-dependent Cushing's syndrome. The patient was a 48-year-old female with clinical and laboratorial data suggesting Cushing's disease. She underwent a transsphenoidal surgery with no tumor visualization and no remission of the syndrome. Histopathological studies disclosed a normal pituitary. She underwent a bilateral adrenalectomy and 8 months later a chest CT showed an increase of left thymic lobe, which was previously non-existent. After a negative (111)In-pentetreotide scintigraphy, the patient underwent simultaneous and bilateral catheterism of the petrosus sinuses and catheterization of the thymic and inominate veins and no ACTH gradient was shown among the sites of collection. She did not undergo thoracotomy and a follow-up was established. During the evolution, there was a spontaneous regression of the thymic lesion 38 months after the diagnosis. The ACTH gradient during the catheterization of thymic vein was essential for the differential diagnosis of the thymic enlargement tumor after hypercortisolism resolution in ACTH-dependent Cushing's syndrome, especially in this case, where the ACTH source was occult, thus avoiding an invasive surgical procedure for a benign entity with spontaneous resolution.

Medical management of pituitary adenomas: the special case of management of the pregnant woman.

The development of efficacious surgical and medical therapies for pituitary adenomas as well as the improvement of hormone therapy for ovulation induction has made pregnancy possible for women harboring pituitary tumors. However, gestational risks due to the possibility of tumor growth during pregnancy, mainly in women with macroadenomas, raise a concern. Bromocriptine has a well-established role for prolactinoma treatment before and during pregnancy, even when a symptomatic tumor increase occurs. It can also be used in acromegaly, despite its poorer results. Somatostatin analogs have been used in acromegaly even during pregnancy with uneventful outcomes, but their safety in pregnancy is not well established, yet. The largest experience with medical treatment for Cushing's disease during pregnancy involves metyrapone, a steroidogenesis inhibitor, without descriptions of congenital abnormalities. Concerning clinically non-functioning pituitary tumors, ovulation induction or even in vitro fertilization are frequently needed. The purpose of this review is to provide an update on therapeutic strategies to restore fertility as well as gestational and post-gestational management of patients with pituitary adenomas, focusing mainly on the role of medical treatment for different tumor types.