MRI in the differential diagnosis of a sellar mass

Imaging and MR Spectroscopy in Papillary Craniopharyngioma

Sellar-suprasellar masses exhibit a diverse range of differential diagnoses and it is feasible to establish a preliminary diagnosis before surgery by evaluating conventional CT scans and contrast-enhanced MRI results. Nevertheless, certain cases may present with inconclusive findings, making it challenging to anticipate the underlying tissue composition accurately through imaging alone. Researchers have explored the application of Proton MR spectroscopy in analyzing suprasellar tumors, and their investigations have revealed that it can complement traditional MRI by enhancing the accuracy of preoperative diagnoses. In this context, we report three biopsy-proven cases of suprasellar papillary craniopharyngioma where the MRS spectra derived from the solid component exhibited noticeable lipid peaks alongside reduced levels of choline and NAA. These findings played a pivotal role in facilitating the correct preoperative identification of papillary craniopharyngioma.

Diagnosis of pituitary abscess and treatment via transsphenoidal surgery: experience from 15 cases

OBJECTIVE

Pituitary abscess is an often misdiagnosed, rare clinical disorder. To improve diagnostic accuracy and the efficacy of surgical and antibiotic therapy for patients with pituitary abscess, herein, we retrospectively reviewed 15 patients who presented with pituitary abscesses from 2005 to 2022.

DESIGN

Retrospective study.

PATIENTS

Fifteen patients underwent transsphenoidal surgery and received antibiotic treatment.

MEASUREMENTS

Complete details regarding medical history, clinical manifestations, laboratory examinations, imaging studies, and treatment strategies were obtained for all patients.

RESULTS

Most patients presented with hypopituitarism and headaches, while some presented with fever, visual disturbances, and diabetes insipidus (DI). Abscesses showed significant annular enhancement post gadolinium injection. In most patients, pituitary abscess can be cured via microscopic or endoscopic drainage of the abscess followed by antibiotic treatment. Complete cure of pituitary abscess was observed in nine patients, with six cases of prolonged hypopituitarism and only one case of recurrence. Long-term hormone replacement therapy was effective in the postoperative management of hypopituitarism.

CONCLUSIONS

The typical manifestations of pituitary abscess include hypopituitarism and headaches; the presence of an enhanced ring at the edge of the mass on contrast-enhanced magnetic resonance images (MRI) is highly suggestive of pituitary abscess. We recommend antibiotic treatment for 4-6 weeks postoperatively, based on the results of bacterial cultures or metagenomic next-generation sequencing (mNGS).

Pituitary Macroadenoma Secondary to Congenital Hypothyroidism With Growth Failure and Developmental Delay: A Rare Presentation

Reactive pituitary hyperplasia can develop as a pituitary (pseudo) macroadenoma in the case of primary hypothyroidism. Hypothyroidism-induced pituitary hyperplasia (PHPH) can be managed medically. Surgery should not be performed if this condition is misdiagnosed as an adenoma. Primary hypothyroidism is a well-known cause of children's slow linear growth. Anterior pituitary enlargement is a rare symptom of severe or long-term illness (pituitary pseudotumor). Thyroid-stimulating hormone-secreting adenomas (TSHomas) are the rarest type of pituitary adenomas, with most endocrinologists seeing just a few cases throughout their lives. In most situations, the diagnosis is difficult, and patients may be referred after presenting with a condition of excessive thyroid-stimulating hormone secretion or a pituitary tumor. In this case study, we describe a 3.5-year-old girl who was referred to our hospital for a surgical assessment of a suspected pituitary neoplastic lesion. It was later determined that the suspected lesion was really pituitary hyperplasia brought on by primary hypothyroidism. Levothyroxine was started, and the dose was increased. The patient was advised to follow up to see if pituitary macroadenoma had responded to levothyroxine supplementation. Pituitary enlargement (pseudotumor of the pituitary gland) is a rare complication of primary hypothyroidism. Early diagnosis and treatment are critical for children with severe primary hypothyroidism to maintain their final height, as late diagnosis nearly always leads to a decline in adult stature. Pituitary macroadenoma secondary to severe hypothyroidism does not need risky and expensive surgical intervention. Because PHPH is rare in children, more credible information is needed to have a better knowledge of how the disease progresses and to develop scientific diagnostic criteria.

Endocrine Tumor Classification via Machine-Learning-Based Elastography: A Systematic Scoping Review

Elastography complements traditional medical imaging modalities by mapping tissue stiffness to identify tumors in the endocrine system, and machine learning models can further improve diagnostic accuracy and reliability. Our objective in this review was to summarize the applications and performance of machine-learning-based elastography on the classification of endocrine tumors. Two authors independently searched electronic databases, including PubMed, Scopus, Web of Science, IEEEXpress, CINAHL, and EMBASE. Eleven (n = 11) articles were eligible for the review, of which eight (n = 8) focused on thyroid tumors and three (n = 3) considered pancreatic tumors. In all thyroid studies, the researchers used shear-wave ultrasound elastography, whereas the pancreas researchers applied strain elastography with endoscopy. Traditional machine learning approaches or the deep feature extractors were used to extract the predetermined features, followed by classifiers. The applied deep learning approaches included the convolutional neural network (CNN) and multilayer perceptron (MLP). Some researchers considered the mixed or sequential training of B-mode and elastographic ultrasound data or fusing data from different image segmentation techniques in machine learning models. All reviewed methods achieved an accuracy of ≥80%, but only three were ≥90% accurate. The most accurate thyroid classification (94.70%) was achieved by applying sequential training CNN; the most accurate pancreas classification (98.26%) was achieved using a CNN-long short-term memory (LSTM) model integrating elastography with B-mode and Doppler images.

Cavernous segment internal carotid artery stenosis specific to meningiomas compared to pituitary adenomas

BACKGROUND AND PURPOSE

Pituitary macroadenomas and meningiomas are common neoplasms arising within the cavernous sinus. Imaging characteristics on MRI can often distinguish these tumors from one another; however, some cases may be more difficult to differentiate. This study compares patterns of cavernous segment internal carotid artery (CS-ICA) stenosis between the two tumor types to establish a novel radiographic method of differentiation.

METHODS

A retrospective analysis of patients with pathology-confirmed meningioma and pituitary adenomas at Tufts Medical Center was performed. The diameter of the CS-ICA at the narrowest point within the cavernous sinus was measured and compared to the ipsilateral petrous segment ICA and contralateral CS-ICA. The mean and range of percent stenosis and frequency of cases of CS-ICA stenosis >15% were determined. Statistical analysis to compare the groups was conducted using the Chi-squared test, Fisher's exact test, and t-test.

RESULTS

There were a total of 78 out of 231 patients who were included in the study. The mean % ICA stenosis for all meningiomas was 9.3%, with increasing stenosis with increasing World Health Organization grade. Of all meningioma cases, 13 (33%) had greater than 15% ICA stenosis. Mean ICA stenosis for pituitary adenomas was -1.48%. There were no cases of pituitary adenomas causing ICA stenosis >15%.

CONCLUSIONS

Differentiating pituitary adenomas and intracavernous meningioma tumors can have important implications on surgical approach and outcome. Our study found that stenosis of the CS-ICA greater than 15% is highly specific to meningiomas and can serve as a radiologic sign to distinguish between these two tumors.

Preoperative differentiation of hypophysitis and pituitary adenomas using a novel clinicoradiologic scoring system

PURPOSE

Hypophysitis can clinically and radiologically mimic other nonfunctioning masses of the sella turcica, complicating preoperative diagnosis. While sellar masses may be treated surgically, hypophysitis is often treated medically, so differentiating between them facilitates optimal management. The objective of our study was to develop a scoring system for the preoperative diagnosis of hypophysitis.

METHODS

A thorough literature review identified published hypophysitis cases, which were compared to a retrospective group of non-functioning pituitary adenomas (NFA) from our institution. A preoperative hypophysitis scoring system was developed and internally validated.

RESULTS

Fifty-six pathologically confirmed hypophysitis cases were identified in the literature. After excluding individual cases with missing values, 18 hypophysitis cases were compared to an age- and sex-matched control group of 56 NFAs. Diabetes insipidus (DI) (p < 0.001), infundibular thickening (p < 0.001), absence of cavernous sinus invasion (CSI) (p < 0.001), relation to pregnancy (p = 0.002), and absence of visual symptoms (p = 0.007) were significantly associated with hypophysitis. Stepwise logistic regression identified DI and infundibular thickening as positive predictors of hypophysitis. CSI and visual symptoms were negative predictors. A 6-point hypophysitis-risk scoring system was derived: + 2 for DI, + 2 for absence of CSI, + 1 for infundibular thickening, + 1 for absence of visual symptoms. Scores ≥ 3 supported a diagnosis of hypophysitis (AUC 0.96, sensitivity 100%, specificity 75%). The scoring system identified 100% of hypophysitis cases at our institution with an estimated 24.7% false-positive rate.

CONCLUSIONS

The proposed scoring system may aid preoperative diagnosis of hypophysitis, preventing unnecessary surgery in these patients.

Machine intelligence in non-invasive endocrine cancer diagnostics

Artificial intelligence (AI) has illuminated a clear path towards an evolving health-care system replete with enhanced precision and computing capabilities. Medical imaging analysis can be strengthened by machine learning as the multidimensional data generated by imaging naturally lends itself to hierarchical classification. In this Review, we describe the role of machine intelligence in image-based endocrine cancer diagnostics. We first provide a brief overview of AI and consider its intuitive incorporation into the clinical workflow. We then discuss how AI can be applied for the characterization of adrenal, pancreatic, pituitary and thyroid masses in order to support clinicians in their diagnostic interpretations. This Review also puts forth a number of key evaluation criteria for machine learning in medicine that physicians can use in their appraisals of these algorithms. We identify mitigation strategies to address ongoing challenges around data availability and model interpretability in the context of endocrine cancer diagnosis. Finally, we delve into frontiers in systems integration for AI, discussing automated pipelines and evolving computing platforms that leverage distributed, decentralized and quantum techniques.

Ocular manifestations of endocrine disorders

Endocrinopathies are prevalent diseases that typically affect multiple organs, and the eye and orbital tissues are often involved in endocrine disorders. Some conditions, such as diabetes and thyroid gland dysfunction, may cause serious eye pathology and even blindness. A clear insight into the pathogenesis of endocrinopathies and their ocular manifestations would enhance preventive and therapeutic measures and reduce the incidence of sight-threatening complications. This review discusses the ocular manifestations of several endocrine disorders that eye care providers are likely to encounter in clinical practice.

Pituitary Tumors in the Computational Era, Exploring Novel Approaches to Diagnosis, and Outcome Prediction with Machine Learning

BACKGROUND

Machine learning has emerged as a viable asset in the setting of pituitary surgery. In the past decade, the number of machine learning models developed to aid in the diagnosis of pituitary lesions and predict intraoperative and postoperative complications following transsphenoidal surgery has increased exponentially. As computational processing power continues to increase, big data sets continue to expand, and learning algorithms continue to surpass gold standard predictive tools, machine learning will serve to become an important component in improving patient care and outcomes.

METHODS

Relevant studies were identified based on a literature search in PubMed and MEDLINE databases, as well as from other sources including reference lists of published articles.

RESULTS

Radiomics and artificial neural networks comprise the majority of machine learning-based applications in pituitary surgery. Radiomics serves to quantify specific imaging features, which can then be used to noninvasively identify tumor characteristics and make definitive diagnoses, circumventing presurgical biopsy altogether. Neural networks can be adapted to predict intraoperative changes in visual evoked potentials or cerebral spinal fluid leak. In addition, these algorithms may be combined with others to predict tumor aggressiveness, gross total resection, recurrence and remission, and even total cost burden.

CONCLUSIONS

The field of machine learning is broad, with radiomics and artificial neural networks comprising 2 commonly used supervised learning methods in pituitary surgery. Given the large heterogeneity of pituitary and sellar lesions, the promise of machine learning lies in its ability to identify relationships and patterns that are otherwise hidden from standard statistical methods. While machine learning has great potential as a clinical adjunct during the surgical preplanning process and in predicting complications and outcomes, challenges moving forward include standardization and validation of these paradigms.

Pituitary Adenomas and Invasiveness from Anatomo-Surgical, Radiological, and Histological Perspectives: A Systematic Literature Review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intra-operative and histological findings.

Differential Clinical Presentation, Intraoperative Management Strategies, and Surgical Outcomes After Endoscopic Endonasal Treatment of Cystic Sellar Masses

BACKGROUND

Cystic sellar masses (CSMs) pose diagnostic and therapeutic challenges associated with subtotal cyst wall resection, cerebrospinal fluid (CSF) leak repair, and disease recurrence. Current magnetic resonance imaging (MRI) interpretation often cannot reliably differentiate CSMs, mandating adaptable intraoperative strategies. We reviewed our diagnostic and therapeutic experience after endoscopic endonasal approaches (EEAs) for CSMs.

METHODS

A retrospective record review of patients with CSM managed via EEA at the University of Southern California from 2011 to 2018 was conducted. Patient demographics, preoperative characteristics, surgical details, pathologic findings, and postoperative outcomes were assessed.

RESULTS

Analysis included 47 patients (mean age, 43.2 years); of these, 78.7% were women. Preoperative symptoms included headache (76.6%) and vision loss (42.6%). Histologically verified sellar pathology included 27 Rathke cleft cysts (RCCs) (57.4%), 17 cystic pituitary adenomas (CPAs) (36.2%), 2 arachnoid cysts (4.3%), and 1 xanthogranuloma (2.1%). Twelve patients (70.6%) with CPAs underwent complete resection and 5 (29.4%) underwent subtotal resection. All 27 patients with RCC and 2 patients with arachnoid cyst underwent complete fenestration and drainage. One xanthogranuloma was completely resected. There were 14 intraoperative (29.8%) and 4 postoperative CSF leaks (8.5%). Headaches, vision, and endocrinopathy improved in 69.2%, 80.0%, and 33.3% of patients with CPA and 73.9%, 71.4%, and 40.9% of patients with RCC, respectively. There were 2 RCC recurrences and 1 CPA recurrence over the follow-up period.

CONCLUSIONS

Surgeons must prepare for versatile management strategies of CSMs based on pretest probability associated with MRI and intraoperative findings. Outcomes after EEA for CSMs show low complication profiles and excellent rates of headache and visual improvement, albeit lower rates of endocrine normalization.

Primary hypothyroidism in a child leads to pituitary hyperplasia: A case report and literature review

RATIONALE

A sellar mass in children is most often seen in craniopharyngeal tumors, intracranial germ cell tumors, or pituitary adenomas. However, pituitary hyperplasia secondary to primary hypothyroidism (PHPH) is not commonly seen in children.

PATIENT CONCERNS

A 10-year-old girl was admitted due to growth retardation and obesity for 4 years. On physical examination, the patient had a height of 118 cm, body weight of 46 kg, body mass index (BMI) of 33.0 kg/m.

DIAGNOSES

After magnetic resonance imaging (MRI) and laboratory tests, her initial diagnosis was Hashimoto's thyroiditis, primary hypothyroidism, and reactive pituitary hyperplasia.

INTERVENTIONS

She was treated with oral L-thyroxine tablets.

OUTCOMES

After 6 months, physical examination showed a height of 125 cm, weight of 36 kg, BMI of 23.0 kg/m. She developed well, with 12 cm of yearly growth thereafter.

LESSONS

The diagnosis of PHPH in a child is very important and sometimes difficult. Based on the summary and analysis of previous cases, we can learn that the main manifestations of PHPH include growth arrest and obesity, perhaps accompanied by symptoms caused by a decreased thyroid hormone concentration and elevated prolactin (PRL) concentration. Intracranial MRI shows diffuse enlargement of the anterior lobe of the pituitary gland, with a dome-shaped blunt edge change. Thyroid hormone levels may decrease, whereas the thyroid stimulating hormone (TSH) level increases, commonly accompanied by an elevated PRL, reduced growth hormone (GH) levels, and positive findings of TPOAb and TGAb. Improvement of symptoms and the normalization of hormone levels as well as restoration of pituitary size can be achieved after treated with thyroid hormone replacement therapy. And a hasty decision on surgical resection should be avoided when the diagnosis is uncertain.

Suprasellar keratinous cyst: A case report and review on its radiological features and treatment outcome

BACKGROUND

Keratinous or epidermoid cysts (ECs) are encapsulated lesions lined by squamous cell epithelium. They comprise approximately 1% of intracranial lesions. Contrary to dermoid cysts, they lack dermal elements such as sebaceous or apocrine glands and hair follicles. The sellar region is the second most common intracranial site following the cerebellopontine angle. Here, we report a case of EC in a patient who complained of endocrine disturbances. We also performed a systematic review on previously published cases to analyze clinical and radiological characteristics and report the treatment outcomes of suprasellar ECs.

CASE DESCRIPTION

A 42-year-old woman presented with a one-year history of amenorrhea, weight gain, severe headache, and visual disturbances for 6 months. Work-up identified an elevated prolactin level and a temporal field defect of the right eye. Magnetic resonance imaging (MRI) showed a cystic suprasellar lesion pushing on the optic chiasm. She underwent endoscopic trans-sphenoidal surgery, which confirmed a keratinous cyst on histology. Postoperatively, complete resection was confirmed on imaging. She did well although her hospital stay was prolonged due to diabetes insipidus and hypocortisolism.

CONCLUSION

Chronic endocrine disturbances can be the presenting complaints of a suprasellar EC, whose T1-weighted MRI appearance can be non-specific, mimicking other differential diagnoses, such as a Rathke's cleft cyst. However, the T2-weighted MRI appearances of ECs are generally hyper-intense and lesions show diffusion restriction. Treatment is surgical and yields good outcomes in most cases reported.

Fluid-fluid level on magnetic resonance images may predict the occurrence of pituitary adenomas in cystic sellar-suprasellar masses

The aim of the present study was to evaluate the value of identifying fluid-fluid level via preoperative magnetic resonance (MR) images in differentiating pituitary adenomas from craniopharyngioma, Rathke's cleft cyst (RCC), and other cystic sellar-suprasellar lesions. The data of 293 consecutive patients who underwent surgery for sellar-suprasellar lesions between July 2010 and December 2012 was retrospectively reviewed, and a total of 133 cystic cases were included in the present study. MR images and pathological features of all subjects were examined. Among the 133 cystic sellar-suprasellar masses, there were 78 cases of pituitary adenomas, 31 cases of craniopharyngioma, 21 cases of RCC, one case of epidermoid cyst and two cases of abscess. Fluid-fluid levels were identified n 43 cases (55.13%) of cystic pituitary adenomas, with a single fluid level in 23 cases, two fluid levels in 8 cases, and three levels or more in 12 cases. Two cases (6.45%) of craniopharyngioma, and one case (4.76%) of RCC presented single fluid level. No instances of fluid-fluid levels were observed in epidermoid cyst or abscess. Fluid-fluid levels were typically exhibited on axial T2-weighted images. The identification of fluid-fluid level in cysts provides useful diagnostic value in distinguishing pituitary adenoma from other sellar-suprasellar lesions. The findings of the present study suggest that a sellar-suprasellar mass with a fluid-fluid level inside the tumor is most likely a pituitary adenoma, particularly if multiple fluid levels are observed in the same tumor. The fluid-fluid level is typically clearly depicted on axial or sagittal MR images, suggesting subacute or chronic hemorrhage in pituitary adenomas.

Pituitary abscess: clinical manifestations, diagnosis and treatment of 66 cases from a large pituitary center over 23 years

PURPOSE

Pituitary abscess (PA) is rare and commonly described in case reports or small case series. This study aimed to better determine salient clinical manifestations related to the diagnosis and appropriate treatment of PA using by far the largest case series of this disease.

METHODS

A total of 6361 consecutive patients underwent surgery for pituitary diseases in Peking Union Medical College Hospital between January 1991 and December 2013. Among this cohort, sixty-six patients were diagnosed with PA based on both intraoperative findings and postoperative histopathological evidence.

RESULTS

The most common clinical presentation was anterior pituitary hypofunction (81.8 %), followed by common headache (69.7 %), diabetes insipidus (DI; 47.9 %), visual disturbances (45.5 %) and symptoms related to infection (43.9 %). Forty patients (66.7 %) showed typical rim enhancement after gadolinium injection on magnetic resonance imaging (MRI). Most patients (63 of 66, 95.5 %) underwent transsphenoidal surgery (TSS), and the remaining 3 patients (4.5 %) were treated with transcranial surgery (TC). After follow-up for 7.2 ± 4.9 years, PA was diminished in most patients (81.8 %), as demonstrated by post-operative MRI, and eight patients underwent at least one additional operation due to recurrence.

CONCLUSIONS

For patients with hypopituitarism and DI with rim enhancement on MRI, we should consider the possible diagnosis of PA. Proper use of antibiotics, complete drainage via surgery and hormone replacement for hypopituitarism are the key treatments for PA.

Imaging of the Sella and Parasellar Region in the Pediatric Population

Masses in the sella and parasellar region comprise about 10% of all pediatric brain tumors but type and frequency differs from those in adults. Imaging is critical for diagnosis and characterization of these lesions. By assessing the site of origin, signal and contrast enhancement characteristics, and the presence or absence of characteristic patterns, differential diagnosis can narrow the possibilities. The clinical presentation is often characteristic for lesion type and should be considered. This article summarizes the characteristic imaging features of the most frequent pediatric tumors and tumor-mimicking lesions in children in this region.

Pituitary abscess: report of two cases and review of the literature

Pituitary abscess is a rare but critical disorder caused by an infectious process where purulent material accumulates inside the sella turcica. Since symptoms, signs and radiographic characteristics of pituitary abscess are similar to several other pituitary lesions, correct diagnosis before surgery is challenging. In this article, two cases of pituitary abscess treated in our department are reported, followed by a literature review. In these two cases, both patients presented with intermittent fever. Magnetic resonance imaging revealed a suprasellar lesion with rim enhancement after contrast injection. After transsphenoidal surgery, the diagnosis of pituitary abscess was confirmed. The patients were then given antibiotic treatment and recovered fully in less than 2 months. Findings of this article support timely diagnosis and proper treatment including transsphenoidal surgery and antibiotic therapy for pituitary abscess, leading to lower mortality rates and higher probability of pituitary hormone function recovery.

Differentiation between Cystic Pituitary Adenomas and Rathke Cleft Cysts: A Diagnostic Model Using MRI

BACKGROUND AND PURPOSE

Cystic pituitary adenomas may mimic Rathke cleft cysts when there is no solid enhancing component found on MR imaging, and preoperative differentiation may enable a more appropriate selection of treatment strategies. We investigated the diagnostic potential of MR imaging features to differentiate cystic pituitary adenomas from Rathke cleft cysts and to develop a diagnostic model.

MATERIALS AND METHODS

This retrospective study included 54 patients with a cystic pituitary adenoma (40 women; mean age, 37.7 years) and 28 with a Rathke cleft cyst (18 women; mean age, 31.5 years) who underwent MR imaging followed by surgery. The following imaging features were assessed: the presence or absence of a fluid-fluid level, a hypointense rim on T2-weighted images, septation, an off-midline location, the presence or absence of an intracystic nodule, size change, and signal change. On the basis of the results of logistic regression analysis, a diagnostic tree model was developed to differentiate between cystic pituitary adenomas and Rathke cleft cysts. External validation was performed for an additional 16 patients with a cystic pituitary adenoma and 8 patients with a Rathke cleft cyst.

RESULTS

The presence of a fluid-fluid level, a hypointense rim on T2-weighted images, septation, and an off-midline location were more common with pituitary adenomas, whereas the presence of an intracystic nodule was more common with Rathke cleft cysts. Multiple logistic regression analysis showed that cystic pituitary adenomas and Rathke cleft cysts can be distinguished on the basis of the presence of a fluid-fluid level, septation, an off-midline location, and the presence of an intracystic nodule (P = .006, .032, .001, and .023, respectively). Among 24 patients in the external validation population, 22 were classified correctly on the basis of the diagnostic tree model used in this study.

CONCLUSIONS

A systematic approach using this diagnostic tree model can be helpful in distinguishing cystic pituitary adenomas from Rathke cleft cysts.

Cerebral aneurysms with intrasellar extension: a systematic review of clinical, anatomical, and treatment characteristics

Object

Intrasellar aneurysms are rare lesions that often mimic pituitary tumors, potentially resulting in catastrophic outcomes if they are not appropriately recognized. The authors aimed to characterize the clinical and anatomical details of this poorly defined entity in the modern era of neuroimaging and open/endovascular neurosurgery.

Methods

A PubMed literature review was conducted to identify all studies reporting noniatrogenic aneurysms with intrasellar extension, as confirmed by CT or MR imaging and angiography. Clinical, anatomical, and treatment characteristics were analyzed.

Results

Thirty-one studies reporting 40 cases of intrasellar aneurysms were identified. Six patients (15%) presented with aneurysmal rupture. Patients with unruptured aneurysms presented with the following signs and symptoms: headache (61%), visual field cuts/decreased visual acuity (61%), endocrinopathy (57%), symptomatic hyponatremia (21%), and cranial nerve paresis (other than optic nerve) (18%). The most common endocrine abnormalities were hyperprolactinemia and hypogonadism. Eight aneurysms (20%) were diagnosed in conjunction with a pituitary adenoma. Aneurysms could be categorized into 2 primary anatomical groups as follows: 1) cavernous/clinoid segment internal carotid artery (ICA) (infradiaphragmatic) aneurysms with medial extension into the sella; and 2) suprasellar (supradiaphragmatic) aneurysms originating from the ophthalmic segment of the ICA or from the anterior communicating artery, with inferomedial extension into the sella. The mean diameters of infradiaphragmatic and supradiaphragmatic aneurysms were 14.5 and 21.8 mm, respectively. Infradiaphragmatic aneurysms were much more likely to present with endocrinopathy, whereas supradiaphragmatic ones presented more commonly with visual disturbances. Aneurysms with infradiaphragmatic growth were generally treated using either endovascular techniques or surgical trapping and bypass, while supradiaphragmatic aneurysms were more often treated by surgical clipping.

Conclusions

Aneurysms with intrasellar extension typically present due to mass effect on surrounding structures, and they can be classified as infradiaphragmatic cavernous or clinoid segment ICA aneurysms, or supradiaphragmatic ophthalmic ICA or anterior communicating artery aneurysms. Varying approaches exist for treating these complex aneurysms, and intervention strategies depend substantially on the anatomical subtype.

Endocrine incidentalomas--challenges imposed by incidentally discovered lesions

Endocrine glands are among the organs that most frequently harbor incidentally discovered lesions. Pituitary, thyroid, parathyroid and adrenal incidentalomas are increasingly encountered in everyday practice with variable clinical implications. The major concerns are the risks of malignancy and hormonal hypersecretion mostly in the form of subclinically functioning tumors. Pituitary incidentalomas are usually microadenomas and most of the time clinically unimportant; however, incidentally discovered larger lesions require a more careful diagnostic and therapeutic approach. Thyroid incidentalomas are extremely common; exclusion of malignancy is the main concern in this clinical setting. Although parathyroid adenomas are not uncommon, these lesions are frequently missed owing to their small size and due to clinical unawareness. Adrenal incidentalomas carry a small but finite risk of malignancy. An intriguing challenge regarding incidentally discovered adrenal lesions is that a substantial proportion is associated with hormonal alterations, mainly in the form of subtle cortisol excess. Although still largely controversial, evidence is emerging that so-called subclinical hypercortisolism may not be completely harmless. The best biochemical criterion of subtle cortisol excess remains elusive. Surgical intervention in selected cases results in some beneficial effects, but more data are required in order to routinely support surgery in this clinical setting. This Review provides a brief overview of the prevalence, clinical effect and management of endocrine incidentalomas with a focus on data regarding the diagnostic and therapeutic challenges imposed by incidentally discovered adrenal lesions.

Pituitary metastases from follicular thyroid carcinoma

BACKGROUND

Metastatic carcinomas to the pituitary gland are uncommon, occurring in only 1% of the pituitary masses. They often originate from breast or lung carcinomas and may resemble a nonfunctioning pituitary adenoma both clinically and radiologically. Here we describe a patient with pituitary metastasis from follicular thyroid carcinoma and discuss the unique features of these lesions.

SUMMARY

A 45-year-old woman was admitted to the emergency rescue room of our hospital with a 2-month history of progressive headache and blurred vision. Evaluation revealed right eye amaurosis, with a mild abducens and oculomotor palsy. Pituitary magnetic resonance imaging showed a mass that was hypo-intense in T1-weighted and hyper-intense in T2-weighted-images, located from the sphenoid sinus up to chiasmatic cisterns, raising and deflecting the optic chiasm, down to hypopharynx region, and distorting the cavernous sinuses. No evidence of anterior or posterior hypopituitarism was recorded. The immediate trans-sphenoidal surgery was uncomplicated with partial improvement of the visual fields and headache. Histopathology revealed a metastasis with well-differentiated follicular thyroid architecture. Total thyroidectomy and lymph node dissection was performed with a final histopathological diagnosis of follicular thyroid carcinoma. Subsequently, her headache became more severe. 131-I ablation treatments were performed 15 days and 12 months after thyroidectomy with decrease in headache and a decline in serum thyroglobulin levels.

CONCLUSIONS

Pituitary metastases from thyroid carcinoma are very uncommon. As this patient illustrates, they tend to produce symptoms relating to space-occupying expansion in the parasellar region rather than to those due to destruction of the pituitary gland. Although rare, pituitary metastases caused by thyroid malignancy should be considered in patients with expanding parasellar lesions if they have thyroid cancer or uncharacterized thyroid diseases. They are unlikely to be amenable to complete resection and should be considered for 131-I treatment, perhaps avoiding the need for extensive neurological surgery.

Incidentally discovered pituitary masses: pituitary incidentalomas

With the widespread use of computed tomography and MRI, the incidental discovery of pituitary incidentalomas is increasing in frequency. The most common cause of a pituitary mass is a pituitary adenoma (90% of all pituitary masses); however, the differential diagnosis remains extensive. The challenge is to distinguish those that can or will cause morbidity/mortality from those that will not. Opinions on approaching management of these lesions vary. This article will review current data regarding the prevalence, natural history and potential morbidity associated with this entity and describe an epidemiological approach based on four questions: does an incidental mass put the patient at increased risk for an adverse outcome? Can individuals with treatable syndromes be accurately diagnosed? Is the treatment of these syndromes more effective in presymptomatic patients? And do the beneficial effects of presymptomatic detection and treatment of these patients justify the costs incurred? We recommend the following approach: recognizing that one size does not fit all and that the approach should be tailored to the needs of the particular case. If the mass was discovered on a computed tomography, an enhanced MRI is recommended. Detailed history and physical examination should be carried out to look for signs of functional or 'subclinically' functional tumor. Size and structure should be assessed, especially proximity to the optic chiasm. Laboratory evaluation with a serum prolactin for small tumors is cost effective, other lab testing is indicated if metabolic problems are present. Care should be taken to assess for hypopituitarism, clinically and biochemically, if the mass is large, that is, more than 1 cm, visual field testing is also recommended. Note that the vast majority of patients with pituitary incidentalomas that are microadenomas die with them, not from them.

A radiologic score to distinguish autoimmune hypophysitis from nonsecreting pituitary adenoma preoperatively

BACKGROUND AND PURPOSE

Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery.

MATERIALS AND METHODS

This was a case-control study of 402 patients, which compared the presurgical pituitary MR imaging features of patients with nonsecreting pituitary adenoma and controls with AH. MR images were compared on the basis of 16 morphologic features besides sex, age, and relation to pregnancy.

RESULTS

Only 2 of the 19 proposed features tested lacked prognostic value. When the other 17 predictors were analyzed jointly in a multiple logistic regression model, 8 (relation to pregnancy, pituitary mass volume and symmetry, signal intensity and signal intensity homogeneity after gadolinium administration, posterior pituitary bright spot presence, stalk size, and mucosal swelling) remained significant predictors of a correct classification. The diagnostic score had a global performance of 0.9917 and correctly classified 97% of the patients, with a sensitivity of 92%, a specificity of 99%, a positive predictive value of 97%, and a negative predictive value of 97% for the diagnosis of AH.

CONCLUSIONS

This new radiologic score could be integrated into the management of patients with AH, who derive greater benefit from medical as opposed to surgical treatment.

Primary hypothyroidism mimicking a pituitary macroadenoma: regression after thyroid hormone replacement therapy

We report a 9-year-old girl with pituitary hyperplasia due to primary hypothyroidism. She presented with growth arrest, abnormal thyroid function studies, and a pituitary mass on MRI. With thyroxine therapy, the pituitary mass regressed and her symptoms resolved. Primary hypothyroidism should be considered in the differential diagnosis of solid mass lesions of the pituitary gland.

Sellar abnormalities in female first-degree relatives

Non-pituitary lesions account for a minority of sellar region abnormalities. We report the unusual occurrence of non-pituitary sellar/suprasellar lesions in a mother and her two daughters. Each of these cases was diagnosed and managed differently, illustrating the relative importance of radiographic imaging, tumor markers and histopathologic examination in the diagnosis and treatment of intracranial disease. The mother had histologically confirmed Rathke's cleft cyst (RCC) with typical radiographic and histologic appearance. One daughter was treated presumptively for germinoma based on characteristic radiographic studies and slightly elevated tumor marker. The other daughter's lesion exhibited radiographic characteristics concerning for pituitary macroadenoma but with slightly elevated germ cell tumor marker, raising the suspicion for germinoma. Biopsy of the intrasellar mass revealed only proteinaceous material and normal anterior pituitary, consistent with cyst content without evidence of neoplasm. Without a clear unifying diagnosis it is difficult to posit an underlying pathology or genetic mechanisms in this unusual set of cases. At least two of the patients had benign cysts. The diagnosis of the third patient is unclear as there was no tissue biopsy. However, it is highly improbable that three female first-degree relatives would develop such lesions in the same brain region simply by chance.

An isolated pituitary metastasis as presentation of a differentiated hepatocellular carcinoma mimicking a nonfunctioning macroadenoma

The differential diagnosis of sellar masses may be complex. Metastatic disease constitutes 1% of all pituitary lesions and sometimes mimics the clinical-radiological presentation of pituitary adenoma. The definitive diagnosis usually relies on histology, but occasionally even histological features of pituitary metastasis may resemble those of adenomas. We present a patient initially diagnosed with pituitary adenoma, but whose clinical course finally revealed pituitary metastasis of a hepatocellular carcinoma. The existing literature on this topic is reviewed.

Evaluation and management of pituitary incidentalomas--revisiting an acquaintance

Incidentalomas of the pituitary gland have been described with increasing frequency, paralleling the advances in diagnostic imaging modalities. Several approaches have been proposed in order to appropriately evaluate their impact on patients, some recommending extensive investigations, while others advocate a more focused and potentially more cost-effective approach. The first part of this article will review current data about the prevalence, natural history and potential morbidity associated with these tumors. The second part will focus on imaging and hormonal evaluation of the incidental mass and suggest an updated management algorithm.

Best Practice No 172: pituitary gland pathology

This article reviews published evidence on the diagnosis and classification of pituitary gland tumours and the relevance of histological and genetic features to prognosis. Much of the literature is devoted to the histological, ultrastructural, and immunocytochemical classification of pituitary adenomas (extensively supported by multicentre studies), with little consensus on the identification of prognostic features in adenomas, particularly in relation to invasion. There is a lack of correspondence between clinical and pathological criteria to identify and classify invasion, and a need to reassess the nomenclature and diagnostic criteria for invasive adenomas and carcinomas. Recent cytogenetic, genetic, and molecular biological studies have identified no consistent abnormalities in relation to pituitary tumour progression, although many genes are likely to be involved. In light of these uncertainties, an approach to the diagnosis and classification of pituitary adenomas is suggested, based on robust criteria from earlier studies and incorporating provisional data that require reassessment in large prospective studies with an adequate clinicopathological database.