Pituitary Incidentalomas Research Articles

Who and how to screen for endogenous hypercortisolism in adrenal and pituitary incidentaloma.

Adrenal incidentalomas (AIs) and pituitary incidentalomas (PIs) have become frequent findings in the last two decades due to the widespread use of cross-sectional imaging in clinical practice. This review investigates the prevalence of endogenous hypercortisolism in patients with AIs and PIs. We aim to underscore the importance of early detection and management of endogenous hypercortisolism in this subset of patients to mitigate associated cardiometabolic complications and reduce mortality. We performed a PubMed literature search to provide updates regarding the prevalence of endogenous hypercortisolism in patients with AIs and PIs, the demographic and clinical characteristics of the studied populations, and the diagnostic test accuracy for early identification of endogenous hypercortisolism. Hypercortisolism, especially mild autonomous cortisol secretion (MACS), was identified in a notable proportion of patients with AIs. MACS was associated with increased cardiometabolic risks, contributing to an elevated overall mortality rate in this cohort. Furthermore, PIs were found to be linked with Cushing's disease in a subset of patients, emphasizing the need for thorough evaluation and monitoring. Early diagnosis and appropriate management of endogenous hypercortisolism are essential in preventing complications and improving patient outcomes. As the presence of undetected hypercortisolism is associated with clinical complications over time, the accurate identification of high-risk populations to screen remains crucial.

A Real-World Longitudinal Study in Non-Functioning Pituitary Incidentalomas: A PRECES Micro-Adenomas Sub-Analysis.

Background. Incidentalomas have an increasing incidence all over the world due to a larger access to imaging assessments, and endocrine incidentalomas make no exception in this matter, including pituitary incidentalomas (PIs). Objective. Our objective was to analyse the dynamic changes amid a second computed tomography (CT) scan after adult patients were initially confirmed with a PI (non-functioning micro-adenoma). Methods. This was a multi-centric, longitudinal, retrospective study in adults (aged between 20 and 70 y) amid real-world data collection. We excluded patients who experienced baseline pituitary hormonal excess or deficiency or those with tumours larger than 1 cm. Results. A total of 117 adults were included (94.02% females) with a mean age of 43.86 ± 11.99 years, followed between 6 and 156 months with a median (M) of 40 months (Q1 Q3: 13.50, 72.00). At the time of PI diagnosis, the transverse diameter had a mean value of 0.53 ± 0.16 cm, the longitudinal mean diameter was 0.41 ± 0.13 cm, and the largest diameter was 0.55 ± 0.16 cm. No PI became functioning during follow-up, neither associated hypopituitarism nor increased >1 cm diameter. A total of 46/117 (39.32%) patients had a larger diameter during follow-up (increase group = IG) versus a non-increase group (non-IG; N = 71, 60.68%) that included the subjects with stationary or decreased diameters. IG had lower initial transverse, longitudinal, and largest diameter versus non-IG: 0.45 ± 0.12 versus 0.57 ± 0.17 (p < 0.0001), 0.36 ± 0.11 versus 0.43 ± 0.13 (p = 0.004), respectively, 0.46 ± 0.12 versus 0.6 ± 0.16 (p < 0.0001). IG versus non-IG had a larger period of surveillance: M (Q1, Q3) of 48 (24, 84) versus 32.5 (12, 72) months (p = 0.045) and showed similar age, pituitary hormone profile, and tumour lateralisation at baseline and displayed a median diameter change of +0.14 cm versus -0.03 cm (p < 0.0001). To conclude, a rather high percent of patients might experience PI diameter increase during a longer period of follow-up, including those with a smaller initial size, while the age at diagnosis does not predict the tumour growth. This might help practitioners with further long-term surveillance protocols.

Multifaceted profile of PTH excess-related secondary osteoporosis: customized therapy and rehabilitation approach

Many causes of secondary osteoporosis have been identified; endocrine types (such as those linked to male hypogonadism, Cushing’s syndrome, acromegaly, thyrotoxicosis, primary hyperparathyroidism, etc.) represent one of the most challenging ailments since a personalized approach of the endocrine disease is simultaneous required. We aimed to introduce the case of a senior lady who was diagnosed with secondary osteoporosis that was associated with primary hyperparathyroidism and a conservative approach was decided, from anti-osteoporosis drug and calcium lowering agents to the physical rehabilitation and lifestyle recommendations. She also presented double unilateral adrenal incidentaloma and a pituitary incidentaloma as well as a suspected ovarian cyst that she further declined to investigate. Mitigating the non-surgical management in primary hyperparathyroidism showcase (in addition to the zoledronic acid for both osteoporosis and hypercalcemia) a complex program of rehabilitation that included a diet intervention in terms of an adequate hydration and a personalized nutrition for kidney stones primary and secondary prevention, mild physical exercise, avoidance of calcium supplements and keeping a daily chole-calciferol replacement.

Adenomas hipofisarios no funcionantes. Incidentaloma hipofisario

Non-functioning pituitary adenomas (NFPAs) are tumors of the pituitary gland that are usually benign and show no clinical or biochemical signs of excessive hormone production. These tumors manifest clinically when they are large enough to exert pressure on surrounding structures. Among pituitary incidentaloma, NFPAs are the most common, as they are often diagnosed accidentally during imaging tests performed for other reasons. To properly evaluate these tumors and their relationship to other structures, the use of contrast-enhanced MRI is preferred. In addition, it is necessary to perform a hormonal analysis to rule out hormonal alterations and a neuro-ophthalmological examination in those cases in which the adenomas are close to the optic chiasm or cavernous sinuses, or in patients who present vision problems. In cases where the tumors are symptomless, observation is an option. However, transsphenoidal surgery is the first-line treatment for patients with symptoms or large tumors. Other options include radiation therapy and medical treatment with dopaminergic agonists and other drugs that are being explored more recently.

Clinical and biochemical data for the diagnosis of endogenous hypercortisolism: the "Cushingomic" approach.

The clinical presentation of Cushing's syndrome (CS) overlaps with common conditions. Recommended screening tests are serum cortisol after 1-mg overnight dexamethasone suppression test (DST), urinary free cortisol (UFC), and late-night salivary cortisol (LNSC). We analyzed the diagnostic accuracy of screening tests in 615 patients without CS (263 suspected CS, 319 adrenal and 33 pituitary incidentaloma) and 40 with CS. Principal component analysis, K-means clustering, and neural network were used to compute an integrated analysis among tests, comorbidities, and signs/symptoms of hypercortisolism. The diagnostic accuracy of screening tests for CS was high, DST and UFC were slightly superior to LNSC. The threshold of DST should be adapted to the population considered, especially in adrenal incidentaloma with mild autonomous cortisol secretion: the cutoff to differentiate CS should be increased to 196 nmol/L. Diabetes, hypertension, and obesity were more common in patients without CS: the direction of their vectors was not aligned and their correlation with screening tests was poor. Clustering allowed us to differentiate those patients without CS in cluster one (aged osteoporotic patients with impaired screening tests), cluster two (hypertensive and metabolic phenotype), and cluster three (young subjects with a low likelihood of overt CS). A neural network model that combined screening tests and clinical presentation was able to predict the CS diagnosis in the validation cohort with 99% precision and 86% accuracy. Despite the high diagnostic accuracy of screening tests to detect CS, cortisol-related comorbidities or adrenal incidentaloma should be considered when interpreting a positive test.

Pituitary Incidentaloma Complicated by Pan Hypopituitarism at the Health Reference Centre of Commune III of the District of Bamako: Case Report

A frequent mode of discovery since the improvement of imaging techniques is the pituitary incidentaloma, defined as the discovery of a pituitary adenoma without clinical signs on a scanner or magnetic resonance imaging (MRI) performed for another reason. We report a case of pituitary macroadenoma complicated by panhypopituitarism, discovered incidentally as part of the macroangiopathic complications of type 2 diabetes at the reference health centre in commune III of the Bamako district. It has poor semiological characteristics but poses a diagnostic problem. In our case, the patient presented with physical asthenia and headaches. On biology, the patient presented with 5 lines of anteropituitary insufficiency. A scan revealed a pituitary adenoma measuring 27x22. Anatomopathological examination of the surgical specimen concluded that it was a pituitary adenoma. The patient received hydrocortisone and thyroid hormones prior to excision. This case highlights the delay in the diagnosis and management of pituitary adenomas.

Obesity-Related pseudo-cushing syndrome and pituitary incidentaloma: a case study

Obesity-Related pseudo-cushing syndrome and pituitary incidentaloma: a case study

Pseudoacromegaly-A challenging entity in the endocrine clinic: A systematic review.

Pseudoacromegaly encompasses conditions with features of acromegaly/gigantism, but no growth hormone (GH) or insulin-like growth factor-1 (IGF-1) excess. We aimed to review published pseudoacromegaly cases evaluated due to clinical suspicion of acromegaly. PubMed/Medline search was conducted to identify reported pseudoacromegaly cases, which were systematically reviewed to ensure they met eligibility criteria: (1) presentation suggestive of acromegaly; (2) acromegaly excluded based on normal GH, IGF-1 and/or GH suppression on oral glucose tolerance test (OGTT-GH); (3) diagnosis of the pseudoacromegaly condition was established. Data were retrieved from each case and analysed collectively. Of 76 cases, 47 were males, mean ages at presentation and at first acromegaloid symptoms were 28 ± 16 and 17 ± 10 years, respectively. Most common conditions were pachydermoperiostosis (47%) and insulin-mediated pseudoacromegaly (IMP) (24%). Acromegaloid facies (75%) and acral enlargement (80%) were the most common features. Measurement of random GH was reported in 65%, IGF-1 in 79%, OGTT-GH in 51%. GH excess was more frequently excluded based on two tests (53%). Magnetic resonance imaging (MRI) was performed in 30 patients, with pituitary adenoma or hyperplasia being reported in eight and three patients, respectively. Investigations differed between cases managed by endocrine and non-endocrine specialists, the former requesting more often IGF-1, OGTT-GH and pituitary MRI. Pseudoacromegaly is a challenging entity that may be encountered by endocrinologists. Pachydermoperiostosis and IMP are the conditions most often mimicking acromegaly. Adequate assessment of GH/IGF-1 is crucial to exclude acromegaly, which may be better performed by endocrinologists. Pituitary incidentalomas are common and require careful judgement to prevent unnecessary pituitary surgery.

Suggestion of Follow-Up Period in Nonfunctioning Pituitary Incidentaloma Based on MRI Characteristics.

For patients diagnosed with asymptomatic, non-functional pituitary incidentaloma (PI), periodic follow-up is generally proposed. However, the recommended follow-up period differs among existing guidelines and consensus is lacking. Thus, this study aimed to suggest follow-up periods for PI based on MRI characteristics. Between 2007 and 2023, 245 patients who were diagnosed with PI were retrospectively assessed. Their mean clinical and neuroradiological follow-up periods were 74.2 and 27.3 months, respectively. Their baseline clinical and neuroradiological characteristics were analyzed. These 245 patients were divided into two groups: those with PI size progression and those without PI size progression. Additionally, neuroradiological features of each group were analyzed according to presumptive diagnoses of PI. PI size increased in 33 of 245 patients. For the remaining 212 patients, PI size decreased or stayed unchanged. Of the 33 patients with PI size progression, ten underwent surgery. Stalk deviation (p<0.001) and lesion enhancement (p=0.001) were significantly more observed in those with PI size progression than in those without PI size progression. MRI morphological factors were not related to changes in PI size in the presumptive Rathke's cleft cyst group. In the presumptive pituitary adenoma group, absence of tumor enhancement (p<0.001) and stalk deviation (p<0.001) were significantly associated with tumor reduction and progression, respectively. Our findings support an additional guideline for patients with asymptomatic non-functional PI without stalk deviation and enhancement. For these patients, the clinical and neuroradiological follow-up periods could be reduced.

Clinically functioning gonadotropin-secreting pituitary adenoma.

Gonadotroph adenomas are the most common type of nonfunctional pituitary adenomas. However, functioning gonadotroph adenomas causing clinical manifestations are rare. We present the case of a 42-year-old man with an incidental finding of a pituitary gland mass. A pituitary MRI revealed a 3 cm macroadenoma, and laboratory investigations revealed elevated follicle-stimulating hormone (FSH) and total testosterone levels. A diagnosis of functioning FSH-secreting pituitary adenoma was considered, with possible concomitant luteinizing hormone secretion, given the elevated testosterone, prompting further evaluation. Testicular ultrasound showed bilaterally enlarged testicles, and visual field testing revealed a monocular superior temporal defect. Transsphenoidal resection of pituitary adenoma was the treatment of choice. Histopathology assessment confirmed the diagnosis of gonadotroph-secreting adenoma, with positive staining for FSH. Within the 12-week postoperative period, FSH and testosterone levels normalized, and the patient experienced significant improvement in vision, along with the resolution of macroorchidism. While functional gonadotroph adenomas are rare, patients can present with a wide range of symptoms that are often unnoticeable due to their slow development. Careful evaluation can help guide multidisciplinary management to achieve full remission. Endocrine evaluation is indicated in all cases of pituitary incidentalomas to determine functional status. Clinically functioning gonadotroph adenomas, while rare, pose a diagnostic challenge and require careful clinical evaluation. Transsphenoidal surgery is the mainstay of treatment of functioning gonadotroph adenomas, with the involvement of a multidisciplinary team to achieve desirable outcomes.

Suggestion of follow-up period in nonfunctioning pituitary incidentaloma based on MRI characteristics

Suggestion of follow-up period in nonfunctioning pituitary incidentaloma based on MRI characteristics

Strikingly low prevalence of pituitary incidentalomas in a teaching hospital in Uruguay.

Pituitary incidentalomas are an occurrence documented in 10.6% of post-mortem examinations, 4%-20% of computed tomography (CT) scans, and 10%-38% of magnetic resonance imaging (MRI) cases, primarily consisting of microincidentalomas (<1 cm in size). However, the prevalence of pituitary incidentalomas in Uruguay remains unexplored. This study aimed to ascertain the prevalence of pituitary incidentalomas at our hospital. In this investigation, we retrospectively identified patients who underwent brain CT and MRI at our hospital over a 1-year span due to conditions other than suspected or known pituitary disorders. The time frame covered was from 1 January to 31 December 2017. Our analysis encompassed all scans, and we conducted interviews with patients discovered to have pituitary incidentalomas. Furthermore, we conducted biochemical assessments in accordance with clinical and imaging traits. During the study period, a total of 3,894 patients underwent imaging procedures. Of these, 1,146 patients underwent MRI scans, and 2,748 underwent CT scans. The mean age was 53.1 ± 19 years, with a relatively even distribution between genders (50.6% women). The majority of imaging requisitions originated from the emergency department (43%), followed by outpatient clinics (29%), and inpatient wards (28%). Common reasons for imaging requests included trauma (20.4%), headaches (11.3%), and stroke (10.9%). Among these cases, two pituitary incidentalomas were detected, resulting in a prevalence of 5 cases per 10,000 individuals annually (0.051%). Both of these cases were initially identified through CT scans, with subsequent MRI scans performed for further assessment. The final diagnoses were a vascular aneurysm and a sellar meningioma, with the latter patient also exhibiting secondary hypothyroidism. Notably, no instances of pituitary adenomas were encountered. The prevalence of pituitary incidentalomas within our hospital was notably low. Further research is necessary to more comprehensively investigate the occurrence of pituitary incidentalomas in our country.

Automated volumetric assessment of pituitary adenoma

PurposeAssessment of pituitary adenoma (PA) volume and extent of resection (EOR) through manual segmentation is time-consuming and likely suffers from poor interrater agreement, especially postoperatively. Automated tumor segmentation and volumetry by use of deep learning techniques may provide more objective and quick volumetry.MethodsWe developed an automated volumetry pipeline for pituitary adenoma. Preoperative and three-month postoperative T1-weighted, contrast-enhanced magnetic resonance imaging (MRI) with manual segmentations were used for model training. After adequate preprocessing, an ensemble of convolutional neural networks (CNNs) was trained and validated for preoperative and postoperative automated segmentation of tumor tissue. Generalization was evaluated on a separate holdout set.ResultsIn total, 193 image sets were used for training and 20 were held out for validation. At validation using the holdout set, our models (preoperative / postoperative) demonstrated a median Dice score of 0.71 (0.27) / 0 (0), a mean Jaccard score of 0.53 ± 0.21/0.030 ± 0.085 and a mean 95th percentile Hausdorff distance of 3.89 ± 1.96./12.199 ± 6.684. Pearson’s correlation coefficient for volume correlation was 0.85 / 0.22 and −0.14 for extent of resection. Gross total resection was detected with a sensitivity of 66.67% and specificity of 36.36%.ConclusionsOur volumetry pipeline demonstrated its ability to accurately segment pituitary adenomas. This is highly valuable for lesion detection and evaluation of progression of pituitary incidentalomas. Postoperatively, however, objective and precise detection of residual tumor remains less successful. Larger datasets, more diverse data, and more elaborate modeling could potentially improve performance.

Acromegaly screening in patients with hyperprolactinemia and pituitary adenoma

Hyperprolactinemia accompanies growth hormone hypersecretion in approximately 25-39% of cases. There is a recommendation to determine the level of prolactin in clinical guidelines for diagnosis and treatment of acromegaly. However, there is no understanding of the necessity to investigate the IGF-1 level in patients with hyperprolactinemia and a pituitary adenoma. Determining the proportion of patients with hyperprolactinemia and pituitary adenoma, who were examined for IGF-1 levels, and identifying the proportion of patients with acromegaly among this cohort. Between December 2019 and December 2022 a single-center observational single-stage single-sample uncontrolled study was conducted. At the first stage of the study, the proportion of patients with pituitary adenoma and hyperprolactinemia with studied IGF-1 levels was determined, according to medical records. At the second stage of the study, patients without known indicators of IGF-1 were determined. The concentration of growth hormone was studied during the oral glucose load in the case of increased IGF-1 levels. At the first stage, 105 patients were included in the study. The level of IGF-1 was determined in 41/105 (39%) cases. There were 22/41 (53.7%) cases in the subgroup with pituitary incidentalomas and 19/64 (29.7%) cases in the subgroup with hyperprolactinemia among them. At the second stage, the IGF-1 level was additionally determined in 53 patients with hyperprolactinemia and pituitary adenoma (total 94 patients). The level of IGF-1 was elevated in 11/94 patients, further acromegaly was confirmed in 3/94 patients (3.2%). In real clinical practice the level of IGF-1 is studied only in 39% of cases in patients with pituitary adenoma and hyperprolactinemia. The disease was detected in 3 cases (3.2%) out of 94 people with hyperprolactinemia and pituitary adenoma without clinical manifestations of acromegaly. We consider the study of IGF-1 levels justified as a screening for acromegaly in patients with hyperprolactinemia and pituitary adenoma.

Surgical indication of pediatric Rathke's cleft cyst based on a 20-year retrospective cohort.

Rathke's cleft cyst (RCC) is the most commonly encountered pituitary incidentaloma in children. Because RCC is not frequently diagnosed in children, there are few reports on pediatric RCCs. The natural course of the disease and appropriate treatments are still obscure. The present study aimed to elucidate the natural history and surgical indications of RCCs in children. The authors retrospectively reviewed the clinical presentations, imaging features, ophthalmological evaluations, endocrine evaluations, and surgical outcomes of pediatric RCCs at a single institution from January 2000 to October 2022. Clinical outcomes between the surgery and observation groups were compared. Among 93 patients, there were 41 patients in the surgery group and 52 patients in the observation group. The mean age at diagnosis was 10.9 years, and the mean follow-up period was 5.6 years. Headache fully or partially improved after surgery (86.2%), but the rate of improvement was not different from that of the observation group (70.0%). Ophthalmological abnormalities were effectively improved by surgical treatment (93.3%). Both the improvement and deterioration rates of endocrine abnormalities were significantly higher in the surgery group (p = 0.026 and p < 0.001, respectively), but the deterioration rate (43.9%) was higher than the improvement rate (14.6%). In the surgery group, the recurrence rate was 17.1% and the reoperation rate was 4.9%. Compared with total cyst wall resection, cyst fenestration with partial wall resection was associated with a higher recurrence rate (26.9%, p = 0.035) but a lower rate of endocrine abnormalities (30.8%, p = 0.049). Pediatric RCCs of ≥ 10 mm in size were analyzed. Ophthalmological abnormalities are the major surgical indications for pediatric RCCs. Headache and partial endocrine abnormalities may be improved with surgery, but they are not absolute indications for surgery. Cyst fenestration with partial wall resection via an endoscopic endonasal approach is the most recommended surgical method. Follow-up is essential to monitor for the occurrence of visual field defects and the recurrence of cysts.

Erythropoiesis in Cushing syndrome: sex-related and subtype-specific differences. Results from a monocentric study

ContextCushing syndrome (CS) is associated with different hematological abnormalities. Nevertheless, conflicting data about erythropoiesis in CS have been reported. Furthermore, it is unclear whether CS sex and subtype-specific alterations in red blood cells (RBC) parameters are present.ObjectiveTo investigate sex and subtype-specific changes in RBC in patients with CS at initial diagnosis and after remission.DesignRetrospective, monocentric study including 210 patients with CS (women, n = 162) matched 1:1 for sex and age to patients with pituitary microadenomas or adrenal incidentalomas (both hormonally inactive). RBC parameters were evaluated at initial diagnosis and after remission.ResultsWomen with CS had higher hematocrit (median 42.2 vs 39.7%), hemoglobin (14.1 vs 13.4 g/dl) and mean corpuscular volume (MCV) (91.2 vs 87.9 fl) compared to the controls (all p < 0.0001). Women with Cushing disease (CD) showed higher hematocrit, RBC and hemoglobin levels than those with ectopic Cushing (ECS) (all p < 0.005). Men with CS had lower hematocrit (42.9 vs 44.7%), RBC count (4.8 vs 5.1n*106/µl) and hemoglobin (14.2 vs 15.4 g/dl), but higher MCV (90.8 vs 87.5 fl) than controls (all p < 0.05). In men with CS, no subtype-specific differences were identified. Three months after remission hemoglobin decreased in both sexes.ConclusionCS is characterized by sexual and subtype-specific differences in RBC parameters. Compared to controls, women with CS showed higher hematocrit/hemoglobin levels, whereas men had lower hematocrit/hemoglobin, which further decreased directly after remission. Therefore, anemia should be considered as complication of CS in men. In women, differences in RBC parameters may help to differentiate CD from ECS.

Abstract #1400950: Chiari I Malformation with Concomitant Nonfunctioning Pituitary and Adrenal Tumors

Chiari I malformation (CM1) is a rare finding with an incidence ranging from 3.3 to 8.2 per 100000. CM1 has been described with growth hormone secreting pituitary adenomas, and with EPAS1 gain-of-function mutation syndrome with multiple paragangliomas/pheochromocytomas, somatostatinoma, and polycythemia. There is only one case report in the literature describing a nonfunctional pituitary adenoma with CM1. We describe the first reported case of a patient with CM1 with concomitant nonfunctional pituitary and adrenal incidentalomas. A 45-year-old female with history of diet-controlled diabetes and HTN presented with a two-week history of bilateral upper extremity weakness and paresthesia, along with gait instability. She had reduced motor power in the upper extremities on physical exam. MRI cervical spine demonstrated a cervicothoracic syrinx, cerebellar tonsillar ectopia consistent with CM1. MRI brain showed diffuse enlargement of the pituitary gland measuring 16 x 14 x 13 mm bulging into the suprasellar cistern and minimally abutting the inferior aspect of the optic chiasm. MRI lumbar spine revealed a left adrenal gland nodule measuring 1.5 x 2.0 cm. Endocrine hormonal evaluation showed normal prolactin, follicle stimulating and luteinizing hormone, estradiol, free T3, free T4, and IGF-I levels. Aldosterone level was high in supine position with normal plasma renin activity initially with normal levels on repeat testing. Plasma free metanephrine, normetanephrine, testosterone levels were also normal. Patient was started on dexamethasone in anticipation of surgery. Patient underwent suboccipital craniectomy, C1 laminectomy, coagulation of cerebellar tonsils and expansile duraplasty for CM1. Patient did well postoperatively and dexamethasone was tapered off. Postoperative follow up after patient had been off steroids for three weeks showed normal levels of all pituitary and adrenal hormones, including normal dexamethasone suppression test. While CM1 is a rare finding, pituitary adenomas are relatively common. In cases of concomitant occurrence of CM1 and growth hormone secreting pituitary adenoma, over-secretion of growth hormone has been proposed as a mechanism to precipitate symptoms of CM1 by causing hypertrophy of connective and ligamentous tissue in the skull base and of the cranio-cervical canal. Our patient had normal IGF-1 levels with a nonfunctional pituitary adenoma raising the question whether there is some other underlying mechanism, possibly a genetic predisposition, that contributed to the concomitant occurrence of CM1 with pituitary and adrenal tumors. Whether these tumors become functional in the future remains to be seen.

Abstract #1371676: A 72-Hour Trial of Octreotide Reliably Distinguishes Between Pituitary and Ectopic ACTH Overproduction in Cushing’s Syndrome

To determine whether the use of an octreotide suppression test will reliably distinguish pituitary from ectopic ACTH overproduction. Somatostatin receptors are expressed in neuroendocrine tumors (NETs), but in Cushing’s disease these are downgraded as the result of hypercortsiolaemia. Octreotide should therefore lower ACTH and cortisol levels in patients with non-pituitary NETs but not in patients with Cushing’s disease and an ACTH producing pituitary tumor. At present the gold standard procedure for distinguishing pituitary from ectopic ACTH overproduction is Inferior petrosal sinus sampling (IPSS) with multiple ACTH measurements. However, this procedure is invasive, expensive and not widely available in many countries. On the other hand, a short trial of octreotide is safe, simple and much cheaper. 13 patents with ACTH dependent Cushing’s syndrome (CS) (8 women, 5 men) with ages ranging between 16 to 40 years were studied. Serum cortisol concentrations were measured at 0800 hrs before and during the administration of Octreotide at a dosage of 100 mcg subcutaneously every 8 hours for 72 hours. The serum cortisol concentrations were suppressed and returned to normal in 4 patients who were later documented to have ectopic disease, two with typical bronchial carcinoids and two with pancreatic NETs and metastatic disease. The other 9 patients had no suppression in serum cortisol concentrations and were documented later to have pituitary tumours. We recommend that a 72-hour octreotide suppression test be given to all patients with ACTH-dependent CS even if the MRI shows an adenoma, so as to exclude the possibility of a pituitary incidentaloma in a patient with ectopic disease.

Management of pituitary incidentalomas

Pituitary incidentalomas are common findings with increasing use of modern neuroradiological imaging undertaken for symptoms unrelated to pituitary disease. The prevalence of these lesions is ∼10% in autopsy studies and the incidence varies from 10% to 38% on magnetic resonance imaging in the published literature. They are almost always benign in nature and most are non-functioning (non-secreting) adenomas. Although many individuals are asymptomatic at diagnosis, some with functioning (secreting) pituitary adenomas or larger non-functioning adenomas have symptoms. All identified cases should have a thorough clinical and endocrinological evaluation to help with precise management, which depends on the size of the lesion, hormonal status (functioning versus non-functioning adenoma) and the presence of visual deficits resulting from optic nerve compression by the pituitary adenoma. Here, we provide an overview of the initial assessment and management of pituitary incidentalomas for clinicians not routinely involved in the management of pituitary disease.

Annals for Educators - March 2023.

Annals for Educators - March 2023.