Neoplastic Etiology and Natural Course of Pituitary Stalk Thickening

A novel diagnostic score for diagnosing arginine vasopressin deficiency (central diabetes insipidus) or primary polydipsia with basal laboratory parameters and a novel diagnostic score: results from two international multicentre prospective diagnostic studies

BACKGROUND

Distinguishing arginine vasopressin deficiency (central diabetes insipidus) from primary polydipsia is challenging. There is no validated initial laboratory assessment or diagnostic score to rule-in or rule-out arginine vasopressin deficiency during the first consultation. Therefore, this study aimed to evaluate the diagnostic potential of basal laboratory parameters and to develop a practical diagnostic score.

METHODS

Data from two international multicentre studies of patients with arginine vasopressin deficiency and primary polydipsia undergoing the hypertonic saline test were used to evaluate the diagnostic potential of basal laboratory tests and to develop a score incorporating laboratory results, symptoms, and medical history. CODDI was a non-randomised, controlled, diagnostic, international, multicentre non-inferiority study in 11 tertiary medical centres in Switzerland, Germany, and Brazil. CARGOx was a randomised, controlled, cross-over, diagnostic, international, multicentre non-inferiority study across seven tertiary medical centres in Switzerland, Germany, the Netherlands, Italy, the UK, and Brazil. Participants were adult patients with polydipsia (>3 L per day) and hypotonic polyuria (>50 mL/kg bodyweight in 24 h and urine osmolality <800 mOsm/kg) and adult patients with a previous diagnosis of arginine vasopressin deficiency. Data were derived from the initial consultation and a basal laboratory test. For each laboratory parameter, the cutoffs resulting in the highest specificity at 100% sensitivity and the highest sensitivity at 100% specificity were identified. For the diagnostic score, the overall best cutoff, high-sensitivity cutoff (≥95% sensitivity), and high-specificity cutoff (≥95% specificity) were identified. Each cutoff was derived from the first study (development), and their performance was determined in the second study (validation). The final score included the sum of: basal plasma sodium multiplied by plasma osmolality, divided by 100; -50 points for plasma copeptin more than 4·9 pmol/L; +30 points for nycturia (≥3 times per night) or +20 points for nycturia (2 times per night); +20 points for sudden polyuria or polydipsia onset; +30 points for drinking more than 1 L per night; +50 points for anterior pituitary dysfunction and +50 points for pituitary surgery history. The diagnostic performance in predicting arginine vasopressin deficiency was examined by the receiver operating characteristic (ROC) area under the curve (AUC) and by sensitivity and specificity. The studies were registered with ClinicalTrials.gov (NCT01940614 and NCT03572166).

FINDINGS

299 patients who underwent the hypertonic saline test from July 1, 2013, to Sept 30, 2022 were included in this analysis. 141 patients were in the development cohort (59 [42%] had arginine vasopressin deficiency; 82 [58%] had primary polydipsia) and 158 patients were in the validation cohort (69 [44%] had arginine vasopressin deficiency; 89 [56%] had primary polydipsia). In the development cohort, the median age of patients with arginine vasopressin deficiency was 45 years (IQR 33-53), with 38 (64%) of 59 being female and 21 (36%) male, compared with a median age of 32 years (IQR 24-44) and 55 (67%) of 82 being female and 27 (33%) male in the group of patients with primary polydipsia. In the validation cohort, patients with arginine vasopressin deficiency had a median age of 42 years (IQR 32-54), with 38 (55%) of 69 being female and 31 (45%) male, compared with a median age of 37 years (IQR 28-50) and 68 (76%) of 89 being female and 21 (24%) male for patients with primary polydipsia. In the validation cohort, basal plasma sodium of more than 145 mmol/L identified arginine vasopressin deficiency with 100% specificity (95% CI 61-100), whereas primary polydipsia was identified by sodium less than 135 mmol/L with 100% specificity (34-100) and by copeptin more than 5·6 pmol/L with 100% specificity (74-100). In the validation cohort, the clinical score had an AUC of 91% (87-96), a cutoff of more than 441 points provided an overall accuracy of 86% (80-91) for diagnosing arginine vasopressin deficiency. In the validation cohort, the high-specificity cutoff of less than 415 points had 93% specificity (87-99) for diagnosing primary polydipsia, and the high-specificity cutoff of more than 461 points had 93% specificity (88-98) for diagnosing arginine vasopressin deficiency. This stepwise approach enabled diagnosis in 223 (75%) of 299 patients.

INTERPRETATION

We introduce a stepwise diagnostic approach, starting with basal laboratory tests and rule-in and rule-out criteria for immediate treatment. For intermediate cases, the novel score aids in identifying arginine vasopressin deficiency or primary polydipsia with high accuracy. This approach could lead to shortening the diagnostic timeline and reducing dependence on stimulation or dynamic tests.

FUNDING

Swiss National Science Foundation.

TRANSLATION

For the German translation of the abstract see Supplementary Materials section.

The progression rate and risk factor analysis of small gastric subepithelial tumors: a systematic review and meta-analysis

BACKGROUND AND AIMS

Small gastric subepithelial tumors (SETs) in the stomach can be managed through surveillance or resection. However, it is still controversial how often the lesion would progress if left untreated. This study aimed to evaluate the progression rate of small SETs and identify risk factors influencing tumor growth.

METHODS

PubMed, Cochrane Library, Web of Science, and Scopus were searched for relevant studies until March 2023. Patient information, endoscopic features of SETs, and surveillance information were extracted from each included study. A random-effects model was applied along with subgroup and sensitivity analyses.

RESULTS

Based on 14 studies with 5405 SETs smaller than 3.5 cm, the annual incidence of size increase was 4.0 (95%CI 2.2-5.8) per 100 person-years, and the overall incidence was 12.8% (95%CI 8.3%-17.3%) across a surveillance duration of 51.3 ± 16.9 months. The predicted risk factors for tumor growth included ≥ 1 cm lesion size (1-2 cm vs. < 1 cm, OR 2.61, 95%CI 1.80-3.79; and > 2 cm vs. 1-2 cm, OR 1.25, 95%CI 0.87-1.81), origin in the muscularis propria (OR 2.09, 95%CI 1.41-3.10), mucosal change (OR 3.27, 95%CI 1.95-5.50), irregular margin (OR 3.16, 95%CI 1.15-8.69), and hypoechoic pattern (OR 3.06, 95%CI 1.34-7.00).

CONCLUSIONS

Most small gastric SETs, particularly those smaller than 1 cm, did not increase in size during surveillance. Special attention should be given to lesions larger than 1 cm, originating from the muscularis propria, or exhibiting mucosal change, irregular margin, and hypoechoic pattern.

Progress in investigating pituitary stalk lesions: A review

Pituitary stalk lesions are uncommon and are typically identified through pituitary magnetic resonance imaging and screening for causes of diabetes insipidus. Recent literature indicates that pituitary stalk lesions primarily manifest as pituitary stalk interruption syndrome and thickening of the pituitary stalk. The etiology of these lesions is complex and can be divided into major categories: congenital disorders, inflammatory or infectious diseases, and tumors. Therefore, achieving accurate diagnosis, differential diagnosis, and treatment for pituitary stalk lesions is crucial. This article aims to classify pituitary stalk lesions and delve into the latest research on their etiology, pathological mechanisms, clinical manifestations, diagnosis, and treatment of associated diseases.

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

A Case of Hypophysitis Associated With SARS-CoV-2 Vaccination

Background/Objective

Although SARS-CoV-2 vaccines have been developed with multiple novel technologies and rapidly disseminated worldwide, the full profile of adverse effects has not been known. Recently, there are sporadic but increasing reports of endocrinopathy in relation to SARS-CoV-2 vaccination. Here we report a rare case of hypophysitis with acute onset of diabetes insipidus, immediately after SARS-CoV-2 vaccination.

Case Report

A 48-year-old female patient had been in her usual state of health until she received the first SARS-CoV-2 vaccine. Two days after vaccination, she started to have flu-like symptoms, including severe headache and myalgia as well as persistent headache, polydipsia, and polyuria. She was diagnosed with diabetes insipidus, and magnetic resonance imaging revealed thickening of the pituitary stalk. Three months after vaccination, her symptoms had somewhat improved, but she still had pituitary stalk thickening on magnetic resonance imaging.

Discussion

Given the timing of the occurrence of diabetes insipidus, we believe that the patient’s hypophysitis may be associated with SARS-CoV-2 vaccination. We also found 19 cases of endocrinopathy after SARS-CoV-2 vaccination by literature search. The reported endocrine organs were the thyroid, pituitary, and adrenals. Twelve cases of diabetes were also reported. Among 3 pituitary cases, diabetes insipidus was reported only in our case.

Conclusion

We report a rare case of SARS-CoV-2 vaccine-triggered hypophysitis, which led to diabetes insipidus. SARS-CoV-2 vaccine–related endocrinopathy seems, indeed, possible. Endocrinopathy is associated with infrequent complications; however, it may be underestimated in the post–SARS-CoV-2-vaccinated population. Further studies are warranted to better understand SARS-CoV-2 vaccine–related endocrinopathy.

Infantile-Onset Isolated Neurohypophyseal Langerhans Cell Histiocytosis with Central Diabetes Insipidus: A Case Report

Central diabetes insipidus (CDI) is a rare disease in children and has a variety of etiologies. The major causes of CDI with pituitary stalk thickening (PST) are germinoma, Langerhans cell histiocytosis (LCH), and Lymphocytic infundibulo-neurohypophysitis, which are difficult to differentiate by imaging and require pathological diagnosis. We report a case of infantile-onset isolated neurohypophyseal LCH diagnosed by pathological findings. A 2-year-old girl presented with polydipsia and polyuria. CDI was diagnosed and treatment with oral desmopressin was initiated. Magnetic resonance imaging (MRI) of the head showed PST and absence of high-signal intensity of posterior pituitary on T1-weighted images. Follow-up MRI scans showed that the tumor mass was gradually increasing and extending posteriorly toward the area near the mamillary body. Simultaneously, anterior pituitary dysfunction was observed. She underwent a biopsy of the PST and LCH was diagnosed by immunohistochemical analysis. DNA analysis showed no BRAF V600E mutation. Monotherapy with 2-Chlorodeoxyadenosine reduced the tumor size but did not improve pituitary function. Isolated neurohypophyseal LCH should be considered in infantile-onset cases of CDI with PST. 2-CdA treatment resulted in rapid PST shrinkage. Further cases are needed to determine whether early diagnosis and treatment can prevent anterior pituitary dysfunction.