Pituitary incidentalomas

Distinguishing Cushing's disease from the ectopic ACTH syndrome: Needles in a haystack or hiding in plain sight?

In the context of ACTH-dependent Cushing's syndrome, ectopic ACTH secretion from a neuroendocrine tumour is not uncommon, and needs to be carefully differentiated from pituitary-dependent Cushing's syndrome, Cushing's disease, in order to optimise therapy. Some cases may be quite obvious, while in others the diagnosis may be difficult to confirm and the source of ACTH problematic, as many clinical and biochemical tests may overlap with Cushing's disease. Imaging is essential, but needs to be interpreted in the light of both anatomical as well as functional imaging modalities. In this review we summarise some of the main diagnostic problems, and emphasise the multimodal and interdisciplinary nature of the diagnostic pathways.

[Pituitary microadenomas - current diagnostic and treatment methods]

According to previously accepted criteria, pituitary microadenoma is characterized by a diameter of less than 10 mm. Improvement and widespread use of MRI are accompanied by increased incidence of diagnosis of these neoplasms. Pituitary microadenomas is an extremely heterogeneous group of tumors with different biological behavior, endocrine secretion and clinical symptoms despite the common MR characteristics. Treatment is mainly determined by endocrine secretion. Endocrine-active microadenoma requires medication (in case of microprolactinoma) and surgical treatment (in case of microsomatotropinoma and ACTH-releasing tumor). Follow-up is advisable for endocrine-inactive microadenoma (microincidentaloma). Modern data on the incidence, clinical and endocrine features, diagnosis and treatment of various pituitary microadenomas are discussed in the article.

Functional imaging in ectopic Cushing syndrome

PURPOSE OF REVIEW

Ectopic adrenocorticotropic hormone (ACTH)-secreting tumors are commonly small, yet they often lead to fulminant forms of Cushing syndrome. High-resolution functional imaging modalities, such as [Ga]-DOTATATE, have been recently introduced in clinical practice for the identification of neuroendocrine tumors. In this review, we focus on the performance of [Ga]-DOTATATE as a tool for localizing primary and metastatic sources of ectopic Cushing syndrome (ECS).

RECENT FINDINGS

Prompt surgical removal of ectopic ACTH-secreting tumors is the mainstay of therapy in patients with ECS. Detecting such tumors with conventional cross-sectional imaging is often unsuccessful, owing to their small size. [Ga]-DOTATATE has been approved in 2016 by the Federal Drug Administration for imaging well differentiated neuroendocrine tumors. Data regarding the performance of [Ga]-DOTATATE for detecting ectopic ACTH-secreting tumors remain limited, in part owing to the recent introduction of this imaging modality in clinical practice, and in part because of the low prevalence of ECS. Nevertheless, [Ga]-DOTATATE has been reported to be useful in identifying primary and metastatic ectopic ACTH-secreting lesions that were not apparent on other imaging studies, impacting the clinical care of many patients with ECS.

SUMMARY

[Ga]-DOTATATE-based imaging, which targets the somatostatin receptors abundantly expressed in neuroendocrine tumors, has generally high, although variable resolution in detecting the source(s) of ECS.

Follicle-stimulating Hormone-secreting Pituitary Adenoma Accompanied by Painful Thyroiditis

A 30-year-old woman with multiple ovarian cysts presented with high serum estradiol levels. She had a pituitary adenoma, but the follicle-stimulating hormone (FSH) concentration was within the normal range. The patient complained of neck pain and palpitations during the disease course, and laboratory results revealed thyrotoxicosis and a systemic inflammatory response with negative findings for anti-thyroid stimulating hormone (TSH) receptor antibody and positive findings for anti-thyroglobulin and anti-thyroid peroxidase antibodies. Prednisolone improved the symptoms and the thyroid function and was discontinued after two months. A histological examination of the pituitary tumor confirmed it to be FSH-producing pituitary adenoma, with subsequent normalization of the serum estradiol concentration.

Spontaneous Pituitary Adenomas in Squirrel Monkeys (Saimiri sciureus)

On postmortem examination, 2 geriatric captive male squirrel monkeys (Saimiri sciureus) were found to have pituitary masses that were unassociated with previous experimental manipulation. Both animals were euthanized due to apparently unrelated clinical reasons. Histopathology and immunohistochemical staining classified these tumors as thyrotrophic and corticotrophic pituitary adenomas. These cases represent the first reports of this tumor type in squirrel monkeys.

The Ectopic Adrenocorticotropic Hormone Syndrome: Rarely Easy, Always Challenging

Despite modern imaging techniques, differentiating ectopic adrenocorticotropic hormone (ACTH) syndrome from pituitary-dependent Cushing's syndrome, Cushing's disease, is especially difficult when well-differentiated carcinoids are the source of ACTH secretion, particularly pulmonary carcinoid tumors. ACTH-secreting pulmonary carcinoids, like the corticotroph adenomas causing Cushing's disease, are often small and difficult to detect, and patients present with a gradual onset of the classical signs and symptoms of Cushing's syndrome, indistinguishable from the presentation of Cushing's disease. Hence, the differential diagnosis relies on a combination of clinical assessment, dynamic biochemical tests, inferior petrosal sinus sampling, and multimodal imaging, each with its own caveats and pitfalls.

Prediction of Long-term Post-operative Testosterone Replacement Requirement Based on the Pre-operative Tumor Volume and Testosterone Level in Pituitary Macroadenoma

Non-functioning pituitary macroadenomas (NFPAs) are the most prevalent pituitary macroadenomas. One common symptom of NFPA is hypogonadism, which may require long-term hormone replacement. This study was designed to clarify the association between the pre-operative tumor volume, pre-operative testosterone level, intraoperative resection status and the need of long-term post-operative testosterone replacement. Between 2004 and 2012, 45 male patients with NFPAs were enrolled in this prospective study. All patients underwent transsphenoidal surgery. Hypogonadism was defined as total serum testosterone levels of <2.4 ng/mL. The tumor volume was calculated based on the pre- and post-operative magnetic resonance images. We prescribed testosterone to patients with defined hypogonadism or clinical symptoms of hypogonadism. Hormone replacement for longer than 1 year was considered as long-term therapy. The need for long-term post-operative testosterone replacement was significantly associated with larger pre-operative tumor volume (p = 0.0067), and lower pre-operative testosterone level (p = 0.0101). There was no significant difference between the gross total tumor resection and subtotal resection groups (p = 0.1059). The pre-operative tumor volume and testosterone level impact post-operative hypogonadism. By measuring the tumor volume and the testosterone level and by performing adequate tumor resection, surgeons will be able to predict post-operative hypogonadism and the need for long-term hormone replacement.

Incidental cranial CT findings in head injury patients in a Nigerian tertiary hospital

BACKGROUND

Incidental findings on computed tomography (CT) scans are occasionally noted in patients presenting with head injury. Since it can be assumed that head injured patients are of normal health status before the accident, these findings may be a representation of their frequency in the general population. Our aim was to determine the prevalence of such incidental findings among head injured patients in Nigeria's foremost center of clinical neurosciences.

MATERIALS AND METHODS

We conducted a retrospective review of CT scan images of 591 consecutive eligible patients over a 5-year period (2006-2010) to identify incidental findings. The images were evaluated by consensus agreement of two radiologists. Associations with gender and age were explored using appropriate statistical tests with an alpha level of 0.05.

RESULTS

The mean patient age was 34.6 ± 21.2 years, and male to female ratio was 3.2: 1. Incidental findings were noted in 503/591 (85.1 %) of the scans. Intracranial calcification was the commonest finding occurring in 61.8% of patients. Over 90% of the findings were benign. Compared with older ones, patients under the age of 60 were less likely, (P < 0.001), to have incidental findings.

CONCLUSION

Although the majority of incidental findings in this African cohort of head injury patients are benign some clinically significant lesions were detectable. It is therefore recommended that such findings be adequately described in the radiological reports for proper counseling and follow-up.

Contemporary indications for transsphenoidal pituitary surgery

OBJECTIVE

To analyze current indications for transsphenoidal pituitary surgery.

METHODS

The current literature regarding transsphenoidal surgery for all subtypes of pituitary adenomas and other sellar lesions was examined. Alternate approaches for pituitary surgery were also reviewed.

RESULTS

Transsphenoidal surgery continues to be the mainstay of surgical treatment for pituitary tumors, and has good outcomes in experienced hands. Pre- and postoperative management of pituitary tumors remains an important part of the treatment of patients with pituitary tumors.

CONCLUSIONS

Even as medical and surgical treatment for pituitary tumors evolves, transsphenoidal surgery remains a mainstay of treatment. Outcomes after transshenoidal surgery have improved over time. Neurosurgeons must be aware of the indications, risks and alternatives to transsphenoidal pituitary surgery.

Pituitary incidentalomas

INTRODUCTION

Incidentally discovered pituitary adenomas are more and more commonly encountered in endocrinology and neurosurgical practices. Often they present as difficult problems in management strategies. This review summarizes the latest evidence and opinions in a variety of settings in which incidental pituitary tumors are discovered, including subclinical pituitary tumor apoplexy.

METHODS

A systematic literature review was accomplished using a spectrum of contemporary sources for information regarding pituitary incidentalomas.

RESULTS

Up to date findings regarding epidemiology, definition of pituitary incidentaloma, patient evaluation, diagnostic studies, and management are presented.

CONCLUSIONS

Current experience from a multidisciplinary pituitary center is presented, with indications for treatment and longitudinal care of these challenging patients.

Evidence-based endocrinology: illustrating its principles in the management of patients with pituitary incidentalomas

Incidentally discovered pituitary lesions are commonly encountered in the current era of ever-increasing imaging. Individualizing a particular approach implies a thorough analysis of existing evidence and balancing it against different patient expectations. We will illustrate the application of principles of Evidence-Based Medicine to a case of a pituitary incidentaloma by formulating questions that are important to patient care and finding related evidence. Our objective is to reflect the opportunities and the challenges that an evidence-based clinical approach offers to clinicians and patients.

The optic chiasm

In the first part of this chapter the anatomy and vascular supply of the chiasm are recounted, and the visual symptoms that may arise in chiasmal disease are noted. The neuro-ophthalmic signs, including the pattern of visual field defects, appearance of the optic disc, and various uncommon clinical accompaniments, are described. The second part deals with a comprehensive list of disease processes that may directly or indirectly affect the chiasm. These are divided into inflammatory disorders, including sarcoidosis, multiple sclerosis, and idiopathic chiasmitis; infective disorders, including tuberculosis; and a large section on tumors, including pituitary adenomas, cysts, and choristomas, malignant disorders, including germ cell tumors and glioma, and meningioma; and finally vascular disorders and compression due to hydrocephalus. In each case the clinical features and management of the disorder are noted, as well as the prognosis for visual improvement following treatment.

Endoscopic surgery of pituitary tumors

Endoscopic pituitary surgery has been gaining wide acceptance as the first-line treatment of most functional pituitary adenomas. This technique has many advantages over traditional procedures, and growing evidence supports its use for endocrine control of functioning tumors. This article reviews data on the different modalities of treatment of functioning pituitary adenomas and compares the results. Endoscopic pituitary surgery controls tumor growth and endocrinopathy as well as or better than other treatment modalities. Complication rates are low and patient recovery is fast. Furthermore, surgery provides a means of achieving prompt decompression of neurologic structures and endocrine remission.

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.

Deteriorated executive functions in patients with successful surgery for pituitary adenomas compared with other chronically ill patients

Pituitary adenomas, even after successful treatment, are associated with cognitive impairments. It is unclear whether these deficits are a consequence of unspecific factors associated with having a chronic illness and whether the cognitive dysfunctions exceed those of other chronically ill patients. Thirty-eight patients with transsphenoidal surgery for pituitary adenomas and 38 patients undergoing L-thyroxine replacement therapy after thyroid surgery were studied neuropsychologically with established tests. Executive function was examined with the Trail-Making Test A and B, working memory with the digit span test, attention with the digit symbol test, verbal memory with the German version of the Auditory Verbal Learning and Memory Test, and general verbal intelligence by a vocabulary test. Attention (p = .007), attentional speed (p = .0004), executive control (p = .04), and working memory (p = .01), were significantly reduced in patients with pituitary adenomas compared with other chronically ill patients. In contrast, no differences were found between the groups for verbal memory (all subtests: p ≥ .06). Patients with successful surgery for pituitary adenomas show also in comparison with other chronically ill patients an increased risk for deficits in certain aspects of cognitive function, including attention and working memory, supporting the relevance of the brain lesion and its treatment for these dysfunctions.

A prospective study of nonfunctioning pituitary adenomas: presentation, management, and clinical outcome

A prospective study was performed to evaluate the presentation, therapeutic management, and clinical outcome of nonfunctioning pituitary adenomas (NFPAs). In most of 385 consecutive patients, NFPAs were macroadenomas. The mean follow-up duration was 5.5 ± 1.4 years. Presentation was dominated by headache, visual disturbance, and hypopituitarism. Pituitary apoplexy (clinical and subclinical) was observed in 88 patients. Appropriate steroids replacement was given before surgery. Endoscope-assisted transsphenoidal surgery (TSS) was performed, and was well tolerated by all patients. At discharge, visual disturbances were improved in 215 (87.6%) patients who had complained of visual impairment preoperatively. The shorter the time from presentation of pituitary apoplexy to surgery, the better the outcome in visual function. Seventy-two (18.7%) patients developed transient diabetes insipidus (DI) and 85 (22.1%) patients developed hyponatremia, but all these improved within six weeks. Hypocortisolism was confirmed in 84 (21.8%) patients with an abnormal postoperative day 2 (POD2) 0800 serum cortisol level and in 122 (31.7%) patients with an abnormal POD6 0800 serum cortisol level. Hypothyroidism occurred in 135 (35.1%) patients. Steroids replacement was thus given immediately. Eight (2.1%) patients needed lifetime hormone substitution. No adrenal crisis occurred. Five (1.3%) patients died within six weeks. Residual tumors were confirmed in 79 patients (20.8%) by postoperative four-month enhanced MR imaging. Tumor recurrence or regrowth occurred in 56 patients (14.7%) during the follow-up period. These patients required repeat TSS or radiosurgery. The findings of this study support the use of TSS as a feasible initial treatment for NFPAs. With appropriate perioperative management of abnormal fluid, electrolyte, and endocrinological function, TSS was associated with minimum morbidity and was well tolerated by patients regardless of age. However, close screening of pituitary function and adequate neuroradiological follow-up should be performed after surgery for detection of tumor recurrence or regrowth. The indications for repeat TSS and postoperative radiosurgery in residual or recurrent NFPAs should be better defined.

Molecular analysis of the PROP1 and HESX1 genes in patients with septo-optic dysplasia and/or pituitary hormone deficiency

OBJECTIVE: The present study aimed at evaluating the PROP1 and HESX1 genes in a group of patients with septo-optic dysplasia (SOD) and pituitary hormone deficiency (combined - CPHD; isolated GH deficiency - GHD). Eleven patients with a clinical and biochemical presentation consistent with CPHD, GHD or SOD were evaluated. SUBJECTS AND METHODS: In all patients, the HESX1 gene was analyzed by direct sequence analysis and in cases of CPHD the PROP1 gene was also sequenced. RESULTS: A polymorphism (1772 A > G; N125S) was identified in a patient with SOD. We found three patients carrying the allelic variants 27 T > C; A9A and 59 A > G; N20S in exon 1 of the PROP1 gene. Mutations in the PROP1 and HESX1 genes were not identified in these patients with sporadic GHD, CPHD and SOD. CONCLUSION: Genetic alterations in one or several other genes, or non-genetic mechanisms, must be implicated in the pathogenic process.

Comparison of multiple methods for identification of hyperprolactinemia in the presence of macroprolactin

BACKGROUND

Macroprolactin is a large, heterogeneous form of prolactin with limited bioavailability. Detection of macroprolactin by different immunoassays varies widely. The objectives of this study were to determine the immunoreactivity of macroprolactin by the Ortho Clinical Diagnostics Vitros((R)) ECi prolactin immunoassay, establish the most effective method for interpreting the prolactin concentration after PEG-precipitation, and correlate the clinical features of hyperprolactinemia with the presence of macroprolactin.

METHODS

PEG-precipitation was performed on 120 hyperprolactinemic specimens. Of these, 31 specimens with a recovery<80% were fractionated by GFC. Four different approaches for identifying true hyperprolactinemia were investigated. Clinical symptoms of hyperprolactinemia were determined by chart review.

RESULTS

Macroprolactin was detected by the Vitros ECi prolactin immunoassay. Use of a PEG modified prolactin reference interval was effective for identifying hyperprolactinemia in the presence of macroprolactin. There was no difference in the prevalence of abnormal menses, galactorrhea, or abnormal MRI between those with and without macroprolactin (p>0.05). Accounting for macroprolactin in patients with hyperprolactinemia reduced the number of idiopathic cases.

CONCLUSIONS

The Vitros ECi prolactin immunoassay detects macroprolactin. PEG-precipitation is an acceptable surrogate to detect hyperprolactinemia in the presence of macroprolactin when using a prolactin reference interval derived from PEG precipitated reference sera. Although testing for macroprolactin should not substitute for standard evaluation of hyperprolactinemia, identification of macroprolactin may clarify a diagnosis and direct appropriate therapy.

Should macroprolactin be measured in all hyperprolactinaemic sera?

Macroprolactin is a nonbioactive prolactin isoform usually composed of a monomer of prolactin and a IgG molecule which has a prolonged clearance rate similar to that of the immunoglobulins. Macroprolactinaemia, hyperprolactinaemia entirely accounted for by the presence of macroprolactin, is estimated to account for approximately 10% of all hyperprolactinaemia coming to clinical attention in the United Kingdom and the United States. Failure to recognize that macroprolactinaemia can explain hyperprolactinaemia, leads to unnecessary investigation, incorrect diagnosis and inappropriate treatment. Screening of hyperprolactinaemic sera for the presence of misleading concentrations of macroprolactin is readily performed in biochemistry laboratories although the procedures have not been automated. The most widely employed method is to treat the hyperprolactinaemic sera with polyethylene glycol which precipitates out high-molecular weight constituents including immunoglobulins. Re-assay of the sera for prolactin will then identify those sera which yield values within the relevant normal range indicative of macroprolactinaemia and not true hyperprolactinaemia. The case for the routine screening of all hyperprolactinaemic sera for macroprolactin is compelling. The consequences of failure to recognize macroprolactinaemia are significant, the problem is frequently encountered, the means of addressing it are immediately available and it is cost effective.

Pancreatic incidentalomas: high rate of potentially malignant tumors

BACKGROUND

Pancreatic incidentaloma (PI) is an increasingly common diagnosis that has received little attention. We characterized these tumors and compared them with symptomatic pancreatic tumors (nonincidentaloma [NI]).

STUDY DESIGN

A retrospective database of 475 consecutive pancreatectomies that were performed from January 1995 to June 2007 at our institution was analyzed. Data for PI and NI patient cohorts were compared.

RESULTS

Sixty-four PIs (13.5%) and 411 NIs (86.5%) were identified; 21% of pancreatic body and tail tumors versus 9% of tumors located in the pancreatic head were incidentally diagnosed (p = 0.001). Twenty-two PIs (34%) versus 278 NIs (67%) were malignant (p < 0.0001), 38 PIs (60%) were premalignant, and the remaining 4 (6%) had little or no risk for malignant progression. Intrapapillary mucinous cystic tumor was the most common diagnosis in the PI group (23.4%, n = 15). Of these, 13.3% (n = 2) were invasive versus 40.6% (n = 15) in the NI group (p = 0.02). Likewise, pathologic features for ductal adenocarcinomas were more favorable in PI versus NI tumors. Overall, PI patients had prolonged median disease-specific survival: 145 versus 46 months (p = 0.001). Median disease-specific survival for PI versus NI patients treated for adenocarcinoma were 22 versus 19 months, respectively (p = 0.4); 5-year disease-specific survival for PI versus NI patients treated for intrapapillary mucinous cystic tumor/mucinous cystadenoma were 94% versus 68%, respectively (p = 0.07).

CONCLUSIONS

Operation for PI is common, and a substantial proportion of these lesions might be malignant or premalignant. Resection of these early tumors in asymptomatic individuals is associated with improved survival, as compared with patients with symptomatic disease.

Long-term outcome of patients with macroprolactinomas initially treated with dopamine agonists

OBJECTIVE

Dopamine agonists are the first line therapy for the treatment of prolactinomas. The aim of this study was to assess the outcome of macroprolactinomas during long-term follow-up after initial treatment with dopamine agonists.

DESIGN

Retrospective follow-up study.

PATIENTS

We included 72 consecutive patients (age 39+/-17 years, men 46%) diagnosed with macroprolactinoma, and initially treated with dopamine agonists between 1980 and 2004.

RESULTS

Initial presentation included headache in 49%, and visual field defects in 38% of the patients. Nine patients were already treated with dopamine agonists at presentation. Median prolactin level of the untreated patients was 460 microg/L (range 96-35,398 microg/L) at presentation. Hypopituitarism, other than hypogonadism, was present in 6% of the patients. Mean duration of follow-up was 10.2+/-6.1 years. Additional transsphenoidal surgery was necessary in 35% of the patients, because of resistance and/or intolerance of dopamine agonists. Postoperative radiotherapy was provided to 18% of all patients. During long-term follow-up, normoprolactinemia was present in 85% of the patients, but biochemical remission (normal prolactin levels in the absence of dopamine agonists) was present in only 22% of the patients. Tumor shrinkage was evident on MRI in 57% of the patients. Hypopituitarism developed in 39% of the patients, especially in those who received additional surgery with or without radiotherapy.

CONCLUSION

Dopamine agonists are effective in normalizing prolactin values, and inducing tumor shrinkage. However, in one-third of the patients, additional therapy was necessary due to dopamine agonist resistance and/or intolerance, associated with a high incidence of hypopituitarism.

Pituitary incidentalomas--how often is too often?

INTRODUCTION

Clinical nonfunctional pituitary microadenomas, also known as incidentalomas are accidental observations made due to the application of high resolution imaging techniques as computed tomography or magnetic resonance. There are no standards regarding the follow-up of these tumors and taking into account their increased frequency among general population (during the last years they were based on the high performances of the imaging methods), we decided to study their dimensions and their evolution over time. We have also analysed their behavior with respect to their endocrine phenotype and the minimum period of time needed for the repetition of the imagistic procedure.

AIM

To observe the natural evolution of tumors' dimensions in a group of patients, diagnosed with nonfunctional pituitary microadenomas based upon hormonal measurements and computed tomography scan.

METHOD

There is a retrospective observational study on 149 patients hospitalized in our Clinic between 1994 and 2006. Initially, all the pituitary hormones and the computed tomography were performed. Only nonfunctional microadenomas were included (the maximum diameter 11 mm). 69 patients were examined for a long period of time--29.75 +/- 24.79 months by CT scan and secretory profile, repeated at different periods of time.

RESULTS

At the end of 29.75 months, the aspect of microadenoma was still present, without any statistically significant changes of the diameter. One of the cases became macroadenoma and another proved to be a microprolactinoma. Only 5 cases of all 149 presented a double lesion. No case of pituitary apoplexy was registered. These observations lead to the conclusion that it is not necessary to repeat the computed tomography scan sooner than 2 years once the diagnosis ofincidentaloma was established.

Treatment and follow-up of clinically nonfunctioning pituitary macroadenomas

CONTEXT

Although the majority of pituitary macroadenomas are clinically nonfunctioning, treatments as well as follow-up strategy for this condition lack evidence from randomized studies.

EVIDENCE ACQUISITION

We evaluated the evidence of treatment and follow-up strategies for clinically nonfunctioning adenomas. PubMed was searched for articles on nonfunctioning adenomas in November 2007, and references of selected articles were assessed for potentially relevant articles.

EVIDENCE SYNTHESIS

All evidence for treatment and follow-up for nonfunctioning adenomas is based on observational studies. The most effective treatment is transsphenoidal surgery, indicated in patients with visual field defects. A wait-and-see approach may be considered in nonfunctioning macroadenomas not reaching to the optic chiasm. Some of these tumors ( approximately 10%) will show spontaneous regression, whereas in approximately 50% there will be progression within 5 yr observation. Postoperative radiotherapy should not be applied to all patients after surgery but can be considered in patients with large postoperative remnants of the tumor. During follow-up careful assessment and replacement of pituitary insufficiencies should be performed. Magnetic resonance imaging is advised with intervals of 1-3 yr and evaluation of visual fields when appropriate. Recurrence rates are reported to be 6-46% after transsphenoidal surgery, whereas after postoperative radiotherapy, recurrence rates of 0-36% are reported. Long-term sequelae of nonfunctioning macroadenomas are hypopituitarism, persistent visual field defects, and decreased quality of life. Whether nonfunctioning macroadenomas are associated with an increased mortality is still a matter of debate.

CONCLUSION

Clinically nonfunctioning pituitary macroadenomas, although benign in nature, need individualized treatment and lifelong radiological and endocrinological follow-up.

The characteristics of incidental pituitary microadenomas in 120 Korean forensic autopsy cases

To investigate the characteristics of incidental pituitary microadenomas, we examined 120 pituitary glands from Korean forensic autopsy cases, from which eight tumors were identified (incidence 6.7%). The average age of the affected subjects was 50 yr (range: 33-96 yr) with a female predominance. The maximum diameters of the tumors ranged from 0.4 to 5.4 mm (mean: 2.8 mm). Immunohistochemical analysis of pituitary hormones revealed three growth hormone-secreting adenomas, one prolactin-producing adenoma, one gonadotropin-producing adenoma, one plurihormonal adenoma, and two null cell adenomas. MIB-1 staining for Ki-67 antigen showed no positive expression. The microvessel density (MVD) of the pituitary microadenomas ranged from 2.3 to 11.6% (mean: 5.3%) and was significantly lower than that of nonneoplastic pituitary glands (11.9-20.1%, mean: 14.8%). Our study provides reference data on incidental pituitary microadenomas in the Korean population.

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.

Periampullary and pancreatic incidentaloma: a single institution's experience with an increasingly common diagnosis

BACKGROUND

While incidental masses in certain organs have received particular attention, periampullary and pancreatic incidentalomas (PIs) remain poorly characterized.

METHODS

We reviewed 1944 consecutive pancreaticoduodenectomies (PD) over an 8-year period (April 1997 to October 2005). A total of 118 patients (6% of all PDs) presented with an incidental finding of a periampullary or pancreatic mass. The PI patients were analyzed and compared with the rest of the cohort (NI, nonincidentaloma group, n = 1826).

RESULTS

Thirty-one percent of the PI patients (n = 37) had malignant disease (versus 76% of the NI patients, P < 0.001), 47% (n = 55) had premalignant disease, and the remaining 22% (n = 26) had little or no risk for malignant progression. The 3 most common diagnoses in the PI group were IPMN without invasive cancer (30%), cystadenoma (17%), and pancreatic ductal adenocarcinoma (10%). The PI group had a higher overall complication rate (55% versus 43%, P = 0.02), due in part to a significantly increased rate of pancreatic fistulas (18.4% PI versus 8.5% NI, P < 0.001). Patients in the PI group with malignant disease had a superior long-term survival (median, 30 months, P = 0.01) compared with patients in the NI group with malignant disease (median, 21 months).

CONCLUSIONS

Incidentally discovered periampullary and pancreatic masses comprise a substantial proportion of patients undergoing PD. Roughly three fourths of these lesions are malignant or premalignant, and amenable to curative resection. Resected malignant PIs have favorable pathologic features as compared with resected malignant NIs, and resection of these early lesions in asymptomatic individuals is associated with improved survival, compared with patients with symptomatic disease.

Natural course of incidentally found nonfunctioning pituitary adenoma, with special reference to pituitary apoplexy during follow-up examination

Object

The increase in the incidental detection of asymptomatic pituitary adenomas, known as “pituitary inciden-talomas,” led the authors to conduct a survey of the natural course of these lesions.

Methods

Forty-two patients with clinically nonfunctioning pituitary adenomas who had manifested no neurological or endocrinological disorders were monitored with magnetic resonance imaging studies. The follow-up period ranged from 10.8 to 168.2 months (mean ± standard deviation, 61.9 ± 38.2 months). The mean initial tumor size was 18.3 ± 7 mm.

In 21 patients, the tumor increased by at least 10% of its measured size on detection. This increase was first detected between 8.4 and 58.8 months (mean 31.8 ± 17.6 months) after diagnosis. There was no correlation between the original tumor size, patient age, or the presence of intratumoral cysts and tumor growth. Symptoms were noted in 10 patients during follow up; in four, extensive tumor necrosis accompanied hemorrhage, leading to severe headache, acute ophthalmological symptoms, and panhypopituitarism, which was indicative of pituitary apoplexy. Transsphenoidal surgery was performed in 12 patients with enlarged tumors, including three with apoplexy. With the exception of one apoplectic patient, visual function was recovered in all who underwent surgery. All apoplectic patients continue to manifest hypopituitarism.

Conclusions

In the course of 4 years, the size of the incidentalomas increased in 40% of 42 patients and became symptomatic in 20%. During the 5-year follow up, pituitary apoplexy developed in 9.5%. These findings may justify early intervention, especially in young individuals with incidentally found macroadenoma.

Diagnosis, misdiagnosis and management of hyperprolactinemia

Hyperprolactinemia is a commonly encountered disorder that suppresses both male and female gonadal function. The etiology includes pituitary tumors, hypothalamic or pituitary stalk lesions, drugs and hypothyroidism. In women, the hyperprolactinemic syndrome is characterized by menstrual disorders with or without galactorrhea, while men present with hypogonadism and related symptoms. Occasionally, a pituitary macroadenoma may be associated with pressure symptoms and/or hypopituitarism. Clinically, the most important cause of hyperprolactinemia is a prolactin-secreting pituitary adenoma. The majority of patients with prolactinomas are successfully managed medically with dopamine agonists such as cabergoline or bromocriptine. Misdiagnosis of hyperprolactinemia owing to immunoassay interference by a biologically minimally active form of prolactin termed macroprolactin is common in laboratory medicine . Alhough the etiology of macroprolactinemia is unclear, the condition is commonly associated with the presence of circulating antiprolactin antibodies. In the absence of specific testing, macroprolactin represents a diagnostic pitfall resulting in misdiagnosis and mismanagement of patients. This review examines the investigation and treatment of hyperprolactinemia in the broadened context of screening for macroprolactin and the consequences of failure to identify its presence.

Clinically non-functioning pituitary adenoma

Non-functioning pituitary tumors are relatively common. A large number of these tumors are incidentally found pituitary microadenomas (<1 cm) and are usually of no clinical importance. Those tumors that require treatment are generally macroadenomas and come to medical attention because of mass effect and/or hypopituitarism. Visual field defects are present in roughly 70% of patients with non-functioning macroadenoma at the time of diagnosis and the majority of these patients have at least growth deficiency and hypogonadism. By immunocytochemistry, the large majority of these tumors are glycoprotein producing and less commonly they are non-functioning somatotroph, lactotroph or corticotoph adenomas. In contrast to the immunocytochemistry results, only a minority of these tumors actively secrete intact gonadotrophs or glycoprotein subunits. Therapy is directed at eliminating mass effect and correcting hypopituitarism. There are anecdotal reports of tumor shrinkage during therapy with either dopamine agonists or somatostatin agonists; however tumor response to medical treatment is not reliable. For most patients, transphenoidal resection of the tumor is the preferable primary treatment. Surgery improves visual defects in the majority of patients and a lesser number will recover pituitary function. In the past, pituitary radiation was commonly administered following pituitary surgery; however the need for routine radiation has recently been reevaluated. Although tumor recurrence at 10 years post surgery may be as high as 50%, few patients with recurrence will have clinical symptoms. Close follow-up with surveillance pituitary scans should be performed after surgery and radiation therapy reserved for patients having significant tumor recurrence.

Comparative proteomics analysis of human pituitary adenomas: current status and future perspectives

This article will review the published research on the elucidation of the mechanisms of pituitary adenoma formation. Mass spectrometry (MS) plays a key role in those studies. Comparative proteomics has been used with the long-term goal to locate, detect, and characterize the differentially expressed proteins (DEPs) in human pituitary adenomas; to identify tumor-related and -specific biomarkers; and to clarify the basic molecular mechanisms of pituitary adenoma formation. The methodology used for comparative proteomics, the current status of human pituitary proteomics studies, and future perspectives are reviewed. The methodologies that are used in comparative proteomics studies of human pituitary adenomas are readily exportable to other different areas of cancer research.

Incidentalomas hipofisários

Lesões hipofisárias clinicamente inaparentes são demonstradas através da ressonância magnética em aproximadamente 10% da população geral adulta, caracterizando os chamados incidentalomas hipofisários. A história natural dessas lesões ainda não está completamente estabelecida. Embora sejam tipicamente pequenos (< 10mm no seu maior diâmetro) e clinicamente silenciosos, alguns incidentalomas hipofisários podem secretar hormônios ou causar efeitos de massa por compressão sobre estruturas vizinhas. Além disso, uma minoria dessas lesões, principalmente aquelas com mais de 10mm (macroincidentalomas) podem crescer com o tempo; assim, o seguimento a longo prazo se faz necessário. Intervenções terapêuticas estão indicadas para os incidentalomas funcionantes (uso de agonistas dopaminérgicos ou ressecção transesfenoidal) ou para aqueles que causem efeitos de massa ou aumentem de tamanho durante o seguimento (ressecção transesfenoidal). Significante extensão supra-selar ou hipopituitarismo podem ser indicações adicionais para o tratamento cirúrgico, mesmo na ausência de compressão quiasmática.

[Nonpituitary tumors of the sellar region]

The pituitary gland, sella turcica and the parasellar region can be involved by a wide variety of lesions, including benign and malignant neoplasms as well as a wide variety of non neoplastic tumor-like lesions. Clinical and radiological aspects could help in the differential diagnosis of these lesions. Nevertheless, in many cases only the histopathological analysis could establish the definitive diagnosis. In this paper, we review the nonpituitary tumors of the sellar region emphasizing the associated hormonal disturbances.

Incidental findings in brain computed tomography scans of 3000 head trauma patients

BACKGROUND

Limited reports exist about intracranial incidental findings on computed tomography (CT) imaging. We studied the frequency of incidental findings on 3000 brain CT scans of trauma patients.

METHODS

Three thousands standard brain CT scans of trauma patients were evaluated for some incidental findings. Cisterna magna was evaluated in 1500 CT scans.

RESULTS

In this study we found 30 incidental abnormalities that include 8 cases of tumor: 3 meningioma, 2 craniopharyngioma, 1 oligodendroglioma, 1 low-grade astrocytoma, and 1 medulloblastoma. Suspect osteoma was found in 3 cases. In 3 cases, abnormal calcification was found in pineal region, basal ganglia, and temporal horn area. Three suspect lipomas were found in midline and near midline of the brain. Arachnoid cyst was found in 7 cases and hydrocephaly in 3 cases. Large cisterna magna (>10 cm(3)) was found in 11 cases.

CONCLUSION

Cisterna magna enlargement was the most common incidental finding and brain tumor and arachnoid cyst were next in frequency.

Hyperadrenocorticism in a dog due to ectopic secretion of adrenocorticotropic hormone

Spontaneous hyperadrenocorticism in dogs is known to be the result of excessive secretion of adrenocorticotropic hormone (ACTH) by the pituitary gland or excessive autonomous glucocorticoid secretion by an adrenocortical tumor. Here, we report on an 8-year-old German shepherd dog in which ACTH-dependent hyperadrenocorticism was a result of ectopic ACTH secretion and could be related to an abdominal neuroendocrine tumor. Hyperadrenocorticism was diagnosed on the basis of the history, clinical signs, and elevated urinary corticoid/creatinine ratios (UCCRs; 236 and 350 x 10(-6); reference range < 10 x 10(-6)). The UCCR remained elevated (226 x 10(-6)) after three oral doses of dexamethasone (0.1 mg/kg body weight) at 8-h intervals. Ultrasonography revealed two equivalently enlarged adrenal glands, consistent with adrenocortical hyperplasia. Plasma ACTH concentration was clearly elevated (159 and 188 ng/l; reference range 5-85 ng/l). Computed tomography (CT) revealed that the pituitary was not enlarged. These findings were interpreted as indicating dexamethasone-resistant pituitary-dependent hyperadrenocorticism. Transsphenoidal hypophysectomy was performed but within 2 weeks after surgery, there was exacerbation of the clinical signs of hyperadrenocorticism. Plasma ACTH concentration (281 ng/l) and UCCRs (1518 and 2176 x 10(-6)) were even higher than before surgery. Histological examination of the pituitary gland revealed no neoplasia. Stimulation of the pituitary with corticotropin-releasing hormone did not affect plasma ACTH and cortisol concentrations. Treatment with trilostane was started and restored normocorticism. CT of the pituitary fossa, 10 months after hypophysectomy, revealed an empty sella. Hence, it was presumed that there was ectopic secretion of ACTH. CT of the abdomen revealed a mass in the region of the pancreas and a few nodules in the liver. Partial pancreatectomy with adjacent lymph node extirpation was performed and the liver nodules were biopsied. Histological examination revealed a metastasized neuroendocrine tumor. Abdominal surgery was not curative and medical treatment with trilostane was continued. At 18 months after the abdominal surgery, the dog is still in good condition. In conclusion, the combination of (1) severe dexamethasone-resistant hyperadrenocorticism with elevated circulating ACTH levels, (2) definitive demonstration of the absence of pituitary neoplasia, and (3) an abdominal neuroendocrine tumor allowed the diagnosis of ectopic ACTH secretion.

Clinical and molecular features of a TSH-secreting pituitary microadenoma

We describe a case of a thyroid stimulating hormone (TSH)-secreting pituitary microadenoma, and report the systematic gene expression profile of the surgically- removed tumor. A 50-year-old woman was referred to our hospital because she had high TSH, free-T4, and free-T3 levels, and a pituitary tumor that was visualized with magnetic resonance imaging. Her basal TSH level was high even after a high T3 loading dose, and increased following administration of thyroid releasing hormone (TRH) even after administration of a high dose of exogenous T3. Her clinical symptoms and peripheral markers for T3 were responsive to exogenous T3. There was no thyroid hormone receptor (TR) beta gene mutation. The patient was diagnosed with a TSH-secreting pituitary adenoma, and trans-sphenoid surgery was performed. The histologic features and immunophenotype were consistent with a TSH-secreting pituitary adenoma. Reverse transcription-polymerase chain reaction analysis of pituitary hormones, pituitary-specific transcription factors, receptors, and transcriptional cofactors of clinical significance was performed on the removed tumor. The tumor expressed TSH, growth hormone, prolactin, alpha-subunit, pituitary transcription factor-1 (pit-1) but not proopiomelanocortin (POMC), prophet of pit-1 (prop-1) and pituitary cell-restricted T box factor (Tpit). TRbeta and TRH-receptor gene expression was normal. Three steroid receptor coactivators (SRC)-1, SRC-2, and SRC-3 were expressed. Nuclear receptor corepressor (N-CoR)2 was absent in the tumor, whereas nuclear receptor corepressor (N-CoR1) was expressed. Somatostatin receptor type 1 expression was significantly decreased, whereas type 4 receptor was expressed, which are unusual characteristics for pituitary tumors. The gene expression pattern in the tumor might have a role in the clinical features of this case.

Hyperprolactinaemia and the regular menstrual cycle in asymptomatic women: should it be treated during therapy for infertility?

It is known that hyperprolactinaemia can cause galactorrhoea and irregular cycles or even amenorrhoea. High serum prolactin (PRL) can disturb follicular maturation and corpus luteum function. Treatment of hyperprolactinaemia in patients with resulting bleeding anomalies is established, but the question is how to manage normal cyclic hyperprolactinaemic women? Studies have shown that in a subgroup of asymptomatic patients the serum contains mainly high molecular weight form (big big PRL), which has a low bioactivity, called macroprolactinaemia. It is evident that macroprolactin does not affect the control of pituitary PRL secretion via the short loop feedback mechanism or the secretion of gonadotrophins as does monomeric PRL. Identification of macroprolactinaemia is therefore clinically important to prevent unnecessary examinations and inappropriate treatment. Prolactinoma can be associated with macroprolactinaemia. Performance of pituitary imaging in asymptomatic patients with hyperprolactinaemia may therefore be justified, but further studies are needed to evaluate the relation of costs and benefit. An unsolved problem is the differentiation between inactive and PRL-secreting tumours. Caution should be exercised concerning medical treatment in unstimulated patients and also in patients during ovarian stimulation alone or in combination with intrauterine insemination or in-vitro fertilization. The potential clinical significance of hyperprolactinaemia/macroprolactinaemia in asymptomatic women must be further evaluated.

Diagnostic and Therapeutic Approach to Pituitary Incidentalomas

OBJECTIVE

To review data on epidemiology, differential diagnosis, clinical, laboratory, and imaging findings, natural history, and management of incidentally discovered pituitary lesions (pituitary incidentalomas).

METHODS

A nonsystematic review was conducted, including articles indexed in Index Medicus that contained reference to incidentally discovered pituitary masses (pituitary incidentalomas).

RESULTS

Both autopsy and sensitive neuroimaging studies (including magnetic resonance imaging) suggest that pituitary incidentalomas are common, affecting approximately 10% of the general population. Although typically small (less than 10 mm in greatest diameter) and clinically silent, some pituitary incidentalomas may be hormonally active or cause mass effects by compressing neighboring structures. In addition, a minority of these lesions may grow over time; hence, long-term follow-up is necessary. Therapeutic interventions, including dopamine agonist therapy (in the case of prolactin-secreting adenomas) or transsphenoidal resection, are indicated in the case of pituitary lesions that are hormonally active, cause mass effects, or increase in size.

CONCLUSION

Pituitary incidentalomas are common and constitute a heterogeneous group with regard to pathologic features, clinical, laboratory, and imaging characteristics, natural history, and growth potential. Currently available evidence suggests that many hormonally nonfunctioning pituitary incidentalomas causing no mass effects can be safely managed by follow-up surveillance. Nonetheless, more data are needed for further elucidation of the natural history of these lesions and for improvement in accurate and noninvasive diagnosis and in prediction of growth potential of pituitary incidentalomas. Improved understanding of the pathogenesis of this heterogeneous group of lesions may also lead to the development of novel, noninvasive therapeutic agents, rationally designed to interact with well-characterized molecular targets.

[Macroprolactin as etiology of hyperprolactinemia. Method for detection and clinical characterization of the entity in 39 patients]

The presence of serum macroprolactin is a relatively frequent situation that can lead to expensive explorations and ineffective treatments. The precipitation with polyethylene glycols permits its detection rapidly, trustworthily, and inexpensively. The objective of the present work has been to assess the incidence of macroprolactin in patients with hyperprolactinemia through its identification with polyethylene glycols, as well as the clinical and radiological findings, and the response in these patients to the treatment. For it the clinical history of all the cases in which there was detected macroprolactinemia, some of them with several years of previous follow-up, was reviewed exhaustively. Of the 1505 patients in which prolactin level was determined, 195 (13%) showed values higher than 40 microg/l. In 39 (20%) of them the presence of macroprolactin was detected. After observing the evolution of these patients, spontaneously or under treatment with dopaminergic agonists, a clear relationship of causality between the presence of macroprolactin and the clinical manifestations was not found, except in a case of galactorrhea. In 27 cases nuclear magnetic resonance was done; in 4 of them a picture was observed compatible with small microadenoma or microcyst and in no patient a macroadenoma was detected. We conclude that the macroprolactinemia is a relatively frequent and easily detected entity through precipitation with polyethylene glycols. It has a limited relation with the clinical findings and there should always be sought other possible causes of this situation. It is an apparently benign situation and its identification can avoid unnecessary explorations and treatments.

Heterogeneity analysis of the human pituitary proteome

BACKGROUND

A human proteome is relatively dynamic compared with its corresponding genome. Our aim was to study the heterogeneity of a human pituitary proteome as a function of gender, age, and race.

METHODS

Pituitary control tissues (n = 8) were used to extract proteins; each control tissue was analyzed (n = 3-5) with two-dimensional gel electrophoresis (2DGE) and PDQuest software. We obtained 30 high-resolution 2DGE gels and conducted a comparative analysis as a function of gender, age, and race. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry and liquid chromatography-electrospray ionization-quadrupole-ion trap tandem mass spectrometry were used to characterize the protein in each differential spot.

RESULTS

We detected approximately 1000 protein spots in each 2DGE map, and 51 differential spots (7 differing with gender, 17 with age, 15 with race, and 12 with the coeffect of age and race). Among those 51, we characterized 28 proteins [5 differing with gender, 8 with age, 6 with race, 8 with the coeffect of age and race, and 1 (somatotropin chain 1) with all of these]. Somatotropin was related to gender, age, and race, and prolactin was higher in females than males. The differentially expressed proteins that were related to age were mainly those proteins associated with cell growth, proliferation, differentiation, apoptosis, and death; those proteins showed no difference with gender and race. Age and race affected some proteins associated with hormone regulation (e.g., follistatin, thyroid hormone receptor beta-2, adenylate cyclase-inhibiting Galpha protein).

CONCLUSIONS

A heterogeneity exists in the human pituitary proteome as a function of gender, age, and race. These findings will serve as a basis for our comparative proteomics studies of human pituitary adenomas.

Macroprolactinemia: a new cause of hyperprolactinemia

Hyperprolactinemia is not only seen in pregnancy but also in several pathological conditions such as prolactin (PRL) secreting pituitary adenoma (prolactinoma), intracranial tumors compressing the pituitary stalk or hypothalamus, and PRL stimulative drugs. However, some patients with hyperprolactinemia are diagnosed as having idiopathic hyperprolactinemia because the causes are unknown. They are subjected to repeated radiological examinations to find a microadenoma, to a long-term treatment with bromocriptine, and even to a surgical intervention. There is accumulating evidence that macroprolactinemia, in which most circulating PRL forms large protein complexes (more than 150 kDa), is a major cause of idiopathic hyperprolactinemia. The patients with macroprolactinemia are clinically characterized by the lack of hyperprolactinemia-related symptoms such as amenorrhea and galactorrhea. We found that anti-PRL autoantibody is a leading cause of macroprolactinemia that might be heterogeneous in nature. Most patients with anti-PRL autoantibodies were symptom-free and pregnancy was possible despite a marked hyperprolactinemia. Identification of macroprolactinemia is clinically important to prevent unnecessary examinations and treatments in patients with idiopathic hyperprolactinemia.

Molecular defects in the pathogenesis of pituitary tumours

The majority of pituitary adenomas are trophically stable and change relatively little in size over many years. A comparatively small proportion behave more aggressively and come to clinical attention through inappropriate hormone secretion or adverse effects on surrounding structures. True malignant behaviour with metastatic spread is very atypical. Pituitary adenomas that come to surgery are predominantly monoclonal in origin and roughly half are aneuploid, indicating either ongoing genetic instability or transition through a period of genetic instability at some time during their development. Few are associated with the classical mechanisms of tumour formation but it is generally believed that the majority harbour quantitative if not qualitative differences in molecular composition compared to the normal pituitary. Despite their prevalence and the ready availability of biopsy material, at the present time, the precise molecular pathogenesis of the majority of pituitary adenomas remains unclear. This review summarizes current thinking.

Cascade effects of medical technology

Cascade effect refers to a process that proceeds in stepwise fashion from an initiating event to a seemingly inevitable conclusion. With regard to medical technology, the term refers to a chain of events initiated by an unnecessary test, an unexpected result, or patient or physician anxiety, which results in ill-advised tests or treatments that may cause avoidable adverse effects and/or morbidity. Examples include discovery of endocrine incidentalomas on head and body scans; irrelevant abnormalities on spinal imaging; tampering with random fluctuations in clinical measures; and unwanted aggressive care at the end of life. Common triggers include failing to understand the likelihood of false-positive results; errors in data interpretation; overestimating benefits or underestimating risks; and low tolerance of ambiguity. Excess capacity and perverse financial incentives may contribute to cascade effects as well. Preventing cascade effects may require better education of physicians and patients; research on the natural history of mild diagnostic abnormalities; achieving optimal capacity in health care systems; and awareness that more is not the same as better.

Influência dos níveis de prolactina e tamanho tumoral na função hipofisária pós-operatória em macroadenomas hipofisários clinicamente não-funcionantes

OBJETIVO: Estudar a influência da hiperprolactinemia e de tamanho tumoral na função hipofisária em macroadenomas hipofisários clinicamente não funcionantes. MÉTODOS: Foram analisados 23 pacientes com macroadenomas hipofisários clinicamente não funcionantes, com exames de imagem (tomografia computadorizada ou ressonância magnética) e dosagens hormonais basais; 16 tinham provas de função hipotálamo-hipofisária (megateste) pré-operatórios. Todos os tumores tiveram diagnóstico histológico e em 17 foi realizado também estudo imuno-histoquímico para os hormônios adeno-hipofisários. A análise estatística foi feita por meio dos testes t de Student, qui-quadrado, exato de Fisher e de Mc Neman. O nível de significância adotado foi 5% (p<0,05). RESULTADOS: O diâmetro tumoral variou de 1,1 a 4,7 cm (média=2,99 cm ± 1,04). No pré-operatório, 5 (21,7%) pacientes não apresentaram déficit hormonal laboratorial, 9 (39,1%) desenvolveram hiperprolactinemia, 13 (56,5%) níveis normais de prolactina (PRL) e 1 (4,3%) subnormal; 18 (78,3%) pacientes desenvolveram hipopituitarismo (4 pan-hipopituitarismo). Dezenove pacientes (82,6%) foram submetidos a via de acesso transesfenoidal, 3 (13%) a craniotomia e 1 (4,4%) ao acesso combinado. Somente 6 pacientes tiveram ressecção tumoral total. Dos 17 submetidos a estudo imuno-histoquímicos, 5 tumores eram imunonegativos, 1 misto, 1 LH+, 1 FSH +, 1 sub-unidade alfa e 8 apresentaram imunorreatividade focal ou em células isoladas para um dos hormônios adeno-hipofisários ou sub-unidades; dos outros seis tumores, 5 eram cromófobos e 1 cromófobo/acidófilo. Não houve correlação estatisticamente significativa entre o diâmetro tumoral e os níveis de PRL pré-operatória (p=0,82), nem entre tamanho tumoral e o estado hormonal pós-operatório, exceto nos eixos GH e gonadotrófico. Foi observada significância estatística entre o tamanho tumoral e o estado hormonal pré-operatório (exceto no eixo gonadal); entre níveis normais de PRL, associados a discreta ou a nenhuma disfunção hipofisária pré-operatória, e recuperação da função hipofisária pós-operatória. CONCLUSÃO: A hiperprolactinemia e tamanho tumoral pré-operatórios isolados não foram preditivos para a recuperação da função hipofisária pós-operatória.

Pitfalls in pituitary diagnosis: peculiarities of three cases

Due to the increasing availability and sensitivity of diagnostic methods, biochemical and imaging abnormalities of pituitary function and anatomy are becoming more frequent. Hyperprolactinaemia was found in three women without any prolactin (PRL) related clinical features. All three patients had normal libido, regular menses with evidence of ovulation, no galactorrhoea, and normal FSH, LH, TSH and free T4 serum levels. Magnetic resonance imaging (MRI) of the sellar region showed images that were compatible with pituitary microadenomas in all three cases. Due to the discordance between laboratory and clinical features, we searched for the presence of PRL aggregates with high molecular weight and low biological activity (macroprolactinaemia). Initially, we screened with a polyethylene glycol precipitation method, and then confirmed the presence of macroprolactinaemia by chromatography. All three cases screened positive for the presence of macroprolactinaemia. MRI alterations, compatible with pituitary microadenomas, may be due to true microincidentalomas, normal anatomical variations or imaging artefacts. In conclusion, we have described the presence of double diagnostic pitfalls that might lead to unnecessary medical or surgical intervention.

Pituitary Adenomas

Treatment of pituitary adenomas can be pharmacologic or surgical. First- line treatment of prolactinomas is usually medical, using either bromocriptine or cabergoline. Other symptomatic pituitary adenomas typically should be treated with transsphenoidal surgery. Radiation therapy can be adjunctive for residual or recurrent tumor. The prognosis for endocrinologic and visual improvement is usually good.