Perioperative hypothalamic pituitary adrenal function in patients with silent corticotroph adenomas

Aggressive nonfunctioning pituitary neuroendocrine tumors

Nonfunctioning pituitary neuroendocrine tumors (NF-PitNETs) are tumors that are not associated with clinical evidence of hormonal hypersecretion. According to the World Health Organization (WHO), there are some subtypes of PitNETs that exhibit more aggressive behavior than others. Among the types of potentially aggressive PitNETs, three are nonfunctional: silent sparsely granulated somatotropinomas, silent corticotropinomas, and poorly differentiated PIT-1 lineage tumors. Several biological markers have been investigated in NF-PitNETs. However, there is no single biomarker able to independently predict aggressive behavior in NF-PitNETs. Thus, a more complex and multidisciplinary proposal of a comprehensive definition of aggressive NF-PitNETs is necessary. Here, we suggest a combined and more complete criterion for the NF-PitNETs classification. We propose that aggressiveness is due to a multifactorial combination, and we emphasize the need to include new emerging markers that are involved in the aggressiveness of NF-PitNETs and the need to identify.

A clinicoradiological analysis of silent corticotroph adenomas after the introduction of pituitary-specific transcription factors

BACKGROUND

Silent corticotroph adenomas (SCAs) are a rare subtype of non-functional pituitary adenoma. While it has been suggested that they are more aggressive and recur more frequently following excision, there is limited literature on the optimum treatment strategy for these tumors, especially regarding the role of radiation therapy in incompletely resected tumors.

METHOD

We assimilated data from 62 SCAs and 238 other non-functional adenomas (ONAs), defined according to the WHO 2017 criteria that incorporates transcription factor analysis. We compared their clinicoradiological characteristics, such as hormonal levels, tumor configuration, size, and invasiveness. For 52 SCAs and 205 ONAs with serial follow-up imaging, we studied outcomes for progression after subtotal resection with or without radiation therapy or recurrence after gross total resection. Kaplan Meier analysis for recurrence or progression was used to determine the need for a differential treatment strategy for SCAs compared with other non-functional adenomas specifically concerning the role of radiotherapy.

RESULTS

Patients with SCAs present at a younger age than ONAs (43.9 years vs. 48.2 years, p = 0.014), with larger (14.9 cc vs. 9.7 cc, p = 0.006) and more invasive adenomas (61.2% vs. 45.8%, p = 0.021). Overall, SCAs are more likely to recur or progress (48.7 vs. 15.7%, p < 0.001) following excision than ONAs, with significantly poorer event-free survival (Log rank test p < 0.001). Early adjuvant radiotherapy provides favorable outcomes among SCAs with postoperative residual tumor, on par with ONAs. Multivariate analysis identified male gender (HR: 2.217; p = 0.017), MIB index ≥ 3% (HR: 2.116; p = 0.012), and SCA tumor pathology (HR: 3.787; p < 0.001) as factors predicting recurrence.

CONCLUSIONS

Based on the results of this retrospective, single-center review of 300 non-functional adenomas, we conclude that silent corticotroph adenomas are an aggressive subtype of non-functional pituitary adenomas that are larger, more likely to be invasive, and tend to recur more frequently after a subtotal excision compared with other non-functional adenomas. A gross total resection must be attempted whenever possible and earlier adjuvant radiation is recommended when re-surgery for residual tumor is difficult.

Clinico-Radiological Features of Tumor-like Lesions of the Upper Limbs: don't worry about those lumps

Tumor-like lesions of the upper limb are more frequent than malignant neoplastic lesions and they represent a wide and heterogeneous group of disorders. The combination of clinical evaluation and imaging is the first pivotal step to attempt a distinction between benign and malignant masses, since there are important implications for further management, such as the requirement for conservative or interventional treatment. The classification of these pseudo tumoral lumps remains arbitrary and is still a matter of debate, currently based on a conjunct clinico-radiologic approach. In this article, we review various types of tumor-like lesions of the upper limb in terms of imaging approach and related clinic features, proponing a descriptive classification, useful in clinical practice to recognize these disorders, and to avoid unnecessary or potentially harmful procedures.

Aggressive Cushing's Disease: Molecular Pathology and Its Therapeutic Approach

Cushing's disease is a syndromic pathological condition caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (ACTHomas) mediated by hypercortisolemia. It may have a severe clinical course, including infection, psychiatric disorders, hypercoagulability, and metabolic abnormalities, despite the generally small, nonaggressive nature of the tumors. Up to 20% of ACTHomas show aggressive behavior, which is related to poor surgical outcomes, postsurgical recurrence, serious clinical course, and high mortality. Although several gene variants have been identified in both germline and somatic changes in Cushing's disease, the pathophysiology of aggressive ACTHomas is poorly understood. In this review, we focused on the aggressiveness of ACTHomas, its pathology, the current status of medical therapy, and future prospects. Crooke's cell adenoma (CCA), Nelson syndrome, and corticotroph pituitary carcinoma are representative refractory pituitary tumors that secrete superphysiological ACTH. Although clinically asymptomatic, silent corticotroph adenoma is an aggressive ACTH-producing pituitary adenoma. In this review, we summarize the current understanding of the pathophysiology of aggressive ACTHomas, including these tumors, from a molecular point of view based on genetic, pathological, and experimental evidence. The treatment of aggressive ACTHomas is clinically challenging and usually resistant to standard treatment, including surgery, radiotherapy, and established medical therapy (e.g., pasireotide and cabergoline). Temozolomide is the most prescribed pharmaceutical treatment for these tumors. Reports have shown that several treatments for patients with refractory ACTHomas include chemotherapy, such as cyclohexyl-chloroethyl-nitrosourea combined with 5-fluorouracil, or targeted therapies against several molecules including vascular endothelial growth factor receptor, cytotoxic T lymphocyte antigen 4, programmed cell death protein 1 (PD-1), and ligand for PD-1. Genetic and experimental evidence indicates that some possible therapeutic candidates are expected, such as epidermal growth factor receptor tyrosine kinase inhibitor, cyclin-dependent kinase inhibitor, and BRAF inhibitor. The development of novel treatment options for aggressive ACTHomas is an emerging task.

Perioperative Glucocorticoid Therapy for Patients with Adrenal Insufficiency: Dosing Based on Pharmacokinetic Data

BACKGROUND

Perioperative glucocorticoid therapy for patients with adrenal insufficiency (AI) is currently based on anecdotal reports, without supporting pharmacokinetic data.

METHODS

We determined the half-life, clearance, and volume of distribution of 2 consecutive intravenously (IV)-administered doses of hydrocortisone (15 or 25 mg every 6 hours) to 22 dexamethasone-suppressed healthy individuals and used the data to develop a novel protocol to treat 68 patients with AI who required surgical procedures. Patients received 20 mg of hydrocortisone orally 2 to 4 hours before intubation and were started on 25 mg of IV hydrocortisone every 6 hours for 24 hours and 15 mg every 6 hours during the second day. Nadir cortisol concentrations were repeatedly measured during that period.

RESULTS

In healthy individuals, cortisol half-life was longer when the higher hydrocortisone dose was administered (2.02 ± 0.15 vs 1.81 ± 0.11 hours; P < 0.01), and in patients with AI, the half-life was longer than in healthy individuals given the same hydrocortisone dose. In both populations, the cortisol half-life increased further with the second hormone injection. Prolongation of cortisol half-life was due to decreased hydrocortisone clearance and an increase in its volume of distribution. Nadir cortisol levels determined throughout the 48 postoperative hours were within the range of values and often exceeded those observed perioperatively in patients without adrenal dysfunction.

CONCLUSIONS

Cortisol pharmacokinetics are altered in the postoperative period and indicate that lower doses of hydrocortisone can be safely administered to patients with AI undergoing major surgery. The findings of this investigation call into question the current practice of administering excessive glucocorticoid supplementation during stress.

Clinical, Laboratory, and Treatment Profiles of Silent Corticotroph Adenomas That Have Transformed to the Functional Type: A Case Series With a Literature Review

Purpose: Silent corticotroph adenoma (SCA) is clinically non-functional pituitary adenoma with expression of corticotropin or Tpit. To further understand the characteristics of this rare type of SCA transforming to a functional SCA, we retrospectively reviewed SCAs that converted to typical Cushing's syndrome at a tertiary medical center and the relevant literature. Methods: Patients were identified based on the diagnosis of pituitary adenoma without symptoms of hypercortisolism at the initial visit with positive Immunohistochemical (IHC) staining for corticotropin or Tpit after surgery and subsequent transformation to functional SCAs during the follow-up period from March 1990 to January 2020 at Peking Union Medical College Hospital and in the literature. The characteristics of the clinical manifestations, biochemical results, imaging findings, pathology findings and outcome were analyzed. Results: Altogether, 16 patients were included in the study with an average age of 42.0 ± 12.48 (18-65) years at the first visit. Females were slightly predominant (F:M = 1.3:1). The median time of conversion from the nonfunctional to the functional type was 30 (13.0, 68.3) months. Once a functional SCA developed, the adrenocorticotropic hormone (ACTH) level and 24-h urine free cortisol were increased 3.8- (2.6, 12.9) and 5.3- (2.6, 19.3) fold, respectively, above the normal range. Approximately 50% of the patients had macrocystic changes on pituitary MRI. All 16 patients experienced 1-5 surgeries with a median of 2.5 (2.0, 4.0) surgeries. The proportion of patients with Ki-67 ≥ 3% increased from 22.2% (2/9) at the beginning to 50% (7/14) at the time of functional SCA diagnosis. Thirteen patients received radiotherapy, and 4 patients (30.8%) achieved remission. Four patients with refractory functional SCAs received temozolomide treatment with the normalization of cortisol in 4 cases and reduced tumor volume in 3 cases. Conclusion: In this study, all cases that transformed to functional SCAs were macroadenomas. Hypercortisolism was more severe in functional SCA patients. The tumors tended to have frequent recurrence and were highly invasive. Temozolomide could be a promising treatment for refractory functional SCA cases. Long-term follow-up is needed for nonfunctional SCAs since some cases have the potential to transform to clinical Cushing's syndrome.

Clinical and Pathological Aspects of Silent Pituitary Adenomas

CONTEXT

Silent pituitary adenomas are anterior pituitary tumors with hormone synthesis but without signs or symptoms of hormone hypersecretion. They have been increasingly recognized and represent challenging diagnostic issues.

EVIDENCE ACQUISITION

A comprehensive literature search was performed using MEDLINE and EMBASE databases from January 2000 to March 2018 with the following key words: (i) pituitary adenoma/tumor and nonfunctioning; or (ii) pituitary adenoma/tumor and silent. All titles and abstracts of the retrieved articles were reviewed, and recent advances in the field of silent pituitary adenomas were summarized.

EVIDENCE SYNTHESIS

The clinical and biochemical picture of pituitary adenomas reflects a continuum between functional and silent adenomas. Although some adenomas are truly silent, others will show some evidence of biochemical hypersecretion or could have subtle clinical signs and, therefore, can be referred to as clinically silent or "whispering" adenomas. Silent tumors seem to be more aggressive than their secreting counterparts, with a greater recurrence rate. Transcription factors for pituitary cell lineages have been introduced into the 2017 World Health Organization guidelines: steroidogenic factor 1 staining for gonadotroph lineage; PIT1 (pituitary-specific positive transcription factor 1) for growth hormone, prolactin, and TSH lineage, and TPIT for the corticotroph lineage. Prospective studies applying these criteria will establish the value of the new classification.

CONCLUSIONS

A concise review of the clinical and pathological aspects of silent pituitary adenomas was conducted in view of the new World Health Organization classification of pituitary adenomas. New classifications, novel prognostics markers, and emerging imaging and therapeutic approaches need to be evaluated to better serve this unique group of patients.

Increased androgen secretion in patients with prolactinomas: the impact of altered HPA function

BACKGROUND AND OBJECTIVES

Earlier studies suggested that hyperprolactinemia was associated with elevated serum DHEA-S levels. The importance of DHEA-S measurements in the diagnosis of adrenal insufficiency prompted us to assess adrenal androgen levels in hyperprolactinemic subjects with normal or impaired function.

METHODS

Prospective study including 122 medically treated and 26 surgically patients with prolactinomas. Serum PRL, DHEA and DHEA-S levels were measured before and repeatedly after cabergoline therapy and also in the perioperative period of surgically treated patients.

RESULTS

Serum PRL levels decreased (P < 0.001) in all 101 medically treated patients with normal HPA function from 728.3 ± 1507 reaching 29.1 ± 39 and 14.9 ± 24.4 µg/L at 3 and 12 months, respectively. Concurrently serum DHEA-S levels decreased (P < 0.001) from 245.9 ± 196 to 216.2 ± 203.3 and to 169.7 ± 121.1 µg/dl at 3 and 12 months, respectively. These effects were reversed in 19 patients who discontinued treatment and were re-demonstrated after therapy resumption. Among the 22 surgically treated patients with normal HPA, peri-operative PRL levels decreased rapidly (P < 0.001) with a parallel decline in serum DHEA-S levels (P = 0.03). Strong correlations were noted between PRL and DHEA-S decrements observed with medical or surgical therapy. Medically (n = 21) and surgically (n = 4) patients with impaired HPA function had very low DHEA-S values that were unchanged despite marked reductions in PRL secretion.

CONCLUSION

Hyperprolactinemia is associated with a reproducible and reversible increase in serum DHEA-S that was observed in medically- and surgically-treated patients with normal HPA function. Thus, a normal age- and gender-adjusted serum DHEA-S level continues to imply normal HPA function even among hyperprolactinemic subjects.

Alterations in hypothalamic-pituitary-adrenal function immediately after resection of adrenal adenomas in patients with Cushing's syndrome and others with incidentalomas and subclinical hypercortisolism

BACKGROUND

Patients with cortisol secreting adrenal adenomas present with Cushing's syndrome (CS), while 5-15% of subjects with adrenal incidentalomas have subclinical hypercortisolism (SH) as they have biochemical abnormalities suggesting autonomous cortisol secretion without associated clinical features of CS.

GOALS

Examine HPA function immediately after resection of either of these adenomas and utilize the data to decide on initiating glucocorticoid replacement.

METHODS

ACTH, cortisol, and DHEA-S levels were measured frequently for 8 h after adrenalectomy in 14 patients with CS and 19 others with incidentalomas + SH. Glucocorticoids were withheld before/during surgery and administered 6-8 h postoperatively to those who had cortisol levels of <3 ug/dL (83 nmol/L).

RESULTS

Preoperatively, incidentalomas + SH patients had larger tumors, higher ACTH, and DHEA-S but lower dexamethasone-suppressed serum cortisol levels than those with CS. Postoperatively, ACTH levels increased in both groups: (90.1 ± 31.6; 24.1 ± 14.4 ng/L, respectively; P < 0.001). Postoperative ACTH levels correlated negatively with preoperative Dexamethasone-suppressed cortisol concentrations in both groups. Patients with CS had steeper decline in cortisol concentrations than those with incidentalomas + SH. All patients with CS had hypocortisolemia requiring glucocorticoid therapy for several months, while only 5/19 with incidentalomas + SH had cortisol levels <3 ug/dL;(83 nmol/L) 6-8 h after adrenalectomy and received hydrocortisone replacement therapy for ≤4 weeks.

CONCLUSIONS

Surgical stress stimulates HPA function even in patients with hypercortisolemia. Patients with incidentalomas + SH have incomplete HPA suppression that allows more robust response to surgical stress than that observed in patients with CS. HPA assessment immediately after surgical resection of adrenal incidentalomas identified those requiring glucocorticoid replacement before discharge.

Silent corticotroph adenomas

PURPOSE

Silent corticotroph adenomas (SCAs) present clinically as non-functioning adenomas (NFAs) but are immunopositive for adrenocorticotrophic hormone (ACTH) without biochemical and clinical manifestation of hypercortisolism. Pathologic examination of resected NFAs that demonstrate positive ACTH and/or TPIT expression confirms its corticotroph lineage. SCAs comprise up to 20% of NFAs and exhibit a higher rate of recurrence. Studies of molecular mechanisms have generated multiple hypotheses on SCA tumorigenesis, pathophysiology, and growth that as yet remain to be proven. An improved understanding of their pathologic and clinical characteristics is needed.

METHODS

A literature review was performed using PubMed to identify research reports and clinical case series on SCAs.

RESULTS

Up to date findings regarding epidemiology, mechanisms of pathogenesis, differentiation, progression, and growth, as well as clinical presentation, postoperative course, and treatment options for patients with SCAs are presented. Pooled results demonstrate that 25-40% of cases show cavernous sinus invasion, preoperative hypopituitarism, new-onset hypopituitarism, and recurrence.

CONCLUSION

This article reviews the incidence, molecular pathology, and clinical behavior of these unique non-functioning pituitary corticotroph adenomas, and highlights the need for rigorous monitoring for recurrences and hypopituitarism in patients with SCAs.

The Value of Perioperative Levels of ACTH, DHEA, and DHEA-S and Tumor Size in Predicting Recurrence of Cushing Disease

CONTEXT AND OBJECTIVES

Despite the development of hypocortisolemia after corticotroph surgical adenomectomy, 15% to 20% patients have recurrence of Cushing disease (CD). In this study, we investigated the effect of tumor size and the value of perioperative assessment of corticotropin (ACTH) and adrenal steroid levels in predicting recurrence.

DESIGN

Perioperatively, no glucocorticoids were administered until the serum cortisol was ≤3 μg/dL. Blood samples were obtained before and repeatedly after adenomectomy in 79 patients with CD. Of these, 66 had a nadir serum cortisol of ≤3.0 μg/dL and clinical and biochemical remissions. During a median follow-up of 131 months, 11 of 66 had disease recurrence (REC), whereas 55 of 66 did not (NO-REC).

RESULTS

Preoperative hormone levels in the REC and NO-REC groups were similar. After adenomectomy, a brief and similar increase in ACTH, cortisol, and dehydroepiandrosterone (DHEA) levels was observed in both groups followed by gradual decline in those levels. Although REC and NO-REC patients had similar cortisol levels (3.4 ± 1.7 μg/dL vs 2.9 ± 2.2 μg/dL) at the 36th postoperative hour, their respective ACTH (33 ± 7.1 ng/L vs 12.1 ± 5.4 ng/L; P < 0.0001), DHEA (3.8 ± 1.7 ng/mL vs 1.2 ± 1.1 ng/mL; P = 0.005), and dehydroepiandrosterone sulphate (DHEA-S) (143.9 ± 45.2 μg/dL vs 48.9 ± 38.2 μg/dL; P < 0.0001) were higher. At nadir hypocortisolemia, perioperative ACTH levels were >20 in all REC patients and <20 ng/L in the NO-REC group. Patients with REC had larger tumors than those with NO-REC.

CONCLUSION

Recurrent CD is characterized by persistent perioperative ACTH secretion after adenomectomy. Higher perioperative levels of ACTH, DHEA, and DHEA-S are highly predictive of future disease recurrence, particularly in those with profound hypocortisolemia.