The prevalence of pituitary adenomas: a systematic review

BACKGROUND

Pituitary adenomas display an array of hormonal and proliferative activity. Once primarily classified according to size (microadenomas, < 1 cm; macroadenomas, > or = 1 cm), these tumors are now further classified according to immunohistochemistry and functional status. With these additional classifications in mind, the goals of the current study were to determine the prevalence of pituitary adenomas and to explore the clinical relevance of the findings.

METHODS

The authors conducted a metaanalysis of all existing English-language articles in MEDLINE. They used the search string (pituitary adenoma or pituitary tumor) and prevalence and selected relevant autopsy and imaging evaluation studies for inclusion.

RESULTS

The authors found an overall estimated prevalence of pituitary adenomas of 16.7% (14.4% in autopsy studies and 22.5% in radiologic studies).

CONCLUSIONS

Given the high frequency of pituitary adenomas and their potential for causing clinical pathologies, the findings of the current study suggest that early diagnosis and treatment of pituitary adenomas should have far-reaching benefits.

Complications of transsphenoidal surgery: results of a national survey, review of the literature, and personal experience

OBJECTIVE

The primary objectives of this report were, first, to determine the number and incidence of complications of transsphenoidal surgery performed by a cross-section of neurosurgeons in the United States and, second, to ascertain the influence of the surgeon's experience with the procedure on the occurrence of these complications. The secondary objective was to review complications of transsphenoidal surgery from the standpoint of their causation, treatment, and prevention.

METHODS

Questionnaires regarding 14 specific complications of transsphenoidal surgery were mailed to 3172 neurosurgeons. The data reported were analyzed from the 958 respondents (82%) who reported performing the operation. The neurosurgeons surveyed were asked to estimate the number of transsphenoidal operations performed, to identify any complications observed, and to estimate the percentage of operations that had resulted in any of the 14 specific complications. The 958 respondents were placed into three experience groups, based on the number of transsphenoidal operations performed. The data were analyzed by using chi 2 tests and Spearman correlation coefficients. The secondary objectives were met through a detailed review of the literature, in light of our experience.

RESULTS

Of the respondents, 87.3% reported having performed < 200 operations and 9.7% reported 200 to 500 previous operations. The remaining 3% reported more than 500 previous operations. More extensive previous experience with transsphenoidal surgery was associated with a greater likelihood of having witnessed each specific complication. The mean operative mortality rate for all three groups was 0.9%. Anterior pituitary insufficiency (19.4%) and diabetes insipidus (17.8%) were complications with the highest incidence of occurrence. The overall incidence of cerebrospinal fluid fistulas was 3.9%. Other significant complications, such as carotid artery injuries, hypothalamic injuries, loss of vision, and meningitis, occurred with incidence rates between 1 and 2%. An inverse relationship was found between the experience group and the likelihood of complications, as indicated by significant negative Spearman correlation coefficients for all but 2 of the 14 complications listed in the survey (P < 0.05). Thus, increased experience with transsphenoidal surgery seems to be associated with a decreased percentage of operations resulting in complications. Some caution should be exercised in interpreting these data, because they are based on the respondents' estimates.

CONCLUSION

Transsphenoidal surgery seems to be a reasonably safe procedure, with a mortality rate of less than 1%. However, a significant number of complications do occur. The incidence of these complications seems to be higher, with statistical significance, in the hands of less experienced surgeons. The learning curve seems to be relatively shallow, because a statistically significantly decreased incidence of morbidity and death could be documented after 200 and even 500 transsphenoidal operations. Better understanding of the indications for transsphenoidal surgery and improved familiarity with the regional anatomy should further lower the incidence of death and morbidity resulting from this procedure in the hands of all neurosurgeons.

Prevalence of pituitary adenomas: a community-based, cross-sectional study in Banbury (Oxfordshire, UK)

BACKGROUND

Pituitary adenomas (PAs) are associated with increased morbidity and mortality. The optimal delivery of services and the provision of care for patients with PAs require distribution of the resources proportionate to the impact of these conditions on the community. Currently, the resource allocation for PAs in the health care system is lacking a reliable and an up-to-date epidemiological background that would reflect the recent advances in the diagnostic technologies, leading to the earlier recognition of these tumours.

OBJECTIVES

To determine the prevalence, the diagnostic delay and the characteristics of patients with PA in a well-defined geographical area of the UK (Banbury, Oxfordshire).

PATIENTS AND METHODS

Sixteen general practitioner (GP) surgeries covering the area of Banbury and a total population of 89 334 inhabitants were asked to participate in the study (data confirmed on 31 July 2006). Fourteen surgeries with a total of 81,449 inhabitants (91% of the study population) agreed to take part. All cases of PAs were found following an exhaustive computer database search of agreed terms by the staff of each Practice and data on age, gender, presenting manifestations and their duration, imaging features at diagnosis, history of multiple endocrine neoplasia type 1 and family history of PA were collected.

RESULTS

A total of 63 patients with PA were identified amongst the study population of 81,149, with a prevalence of 77.6 PA cases/100,000 inhabitants (prolactinomas; PRLoma: 44.4, nonfunctioning PAs: 22.2, acromegaly; ACRO: 8.6, corticotroph adenoma: 1.2 and unknown functional status; UFS: 1.2/100,000 inhabitants). The distribution of each PA subtype was for PRLoma 57%, nonfunctioning PAs 28%, ACRO 11%, corticotroph adenoma 2% and UFS 2%. The median age at diagnosis and the duration of symptoms until diagnosis (in years) were for PRLoma 32.0 and 1.5, nonfunctioning PAs 51.5 and 0.8, ACRO 47 and 4.5 and corticotroph adenoma 57 and 7, respectively. PRLoma was the most frequent PA diagnosed up to the age of 60 years (0-20 years: 75% and 20-60 years: 61% of PAs) and nonfunctioning PA after the age of 60 years (60% of PAs). Nonfunctioning PAs dominated in men (57% of all men with PA) and PRLoma in women (76% of all women with PA). Five patients (7.9%) presented with classical pituitary apoplexy, with a prevalence of 6.2 cases/100,000 inhabitants.

CONCLUSIONS

Based on a well-defined population in Banbury (Oxfordshire, UK), we have shown that PAs have a fourfold increased prevalence than previously thought; our data confirm that PAs have a higher burden on the Health Care System and optimal resource distribution for both clinical care and research activities aiming to improve the outcome of these patients are needed.

High prevalence of pituitary adenomas: a cross-sectional study in the province of Liege, Belgium

CONTEXT

Prevalence data are important for assessing the burden of disease on the health care system; data on pituitary adenoma prevalence are very scarce.

OBJECTIVE

The objective of the study was to measure the prevalence of clinically relevant pituitary adenomas in a well-defined population.

DESIGN

This was a cross-sectional, intensive, case-finding study performed in three regions of the province of Liège, Belgium, to measure pituitary adenoma prevalence as of September 30, 2005.

SETTING

The study was conducted in specialist and general medical practitioner patient populations, referral hospitals, and investigational centers.

METHODS

Three demographically and geographically distinct districts of the province of Liège were delineated precisely using postal codes. Medical practitioners in these districts were recruited, and patients with pituitary adenomas under their care were identified. Diagnoses were confirmed after retrieval of clinical, hormonal, radiological, and pathological data; full demographic and therapeutic follow-up data were collected in all cases.

RESULTS

Sixty-eight patients with clinically relevant pituitary adenomas were identified in a population of 71,972 individuals; the mean (+/- sd) prevalence was 94 +/- 19.3 cases per 100,000 population (95% confidence interval, 72.2 to 115.8). The group was 67.6% female and had a mean age at diagnosis of 40.3 yr; 42.6% had macroadenomas and 55.9% underwent surgery. Prolactinomas comprised 66% of the group, with the rest having nonsecreting tumors (14.7%), somatotropinomas (13.2%), or Cushing's disease (5.9%); 20.6% had hypopituitarism.

CONCLUSION

The prevalence of pituitary adenomas in the study population (one case in 1064 individuals) was more than 3.5-5 times that previously reported. This increased prevalence may have important implications when prioritizing funding for research and treatment of pituitary adenomas.

The descriptive epidemiology of craniopharyngioma

OBJECT

In this report the authors describe the epidemiology of craniopharyngioma.

METHODS

The incidence of craniopharyngioma in the United States was estimated from two population-based cancer registries that include brain tumors of benign and borderline malignancy: the Central Brain Tumor Registry of the United States (CBTRUS) and the Los Angeles county Cancer Surveillance Program. Information on additional pediatric tumors was available from the Greater Delaware Valley Pediatric Tumor Registry (GDVPTR). The overall incidence of craniopharyngioma was 0.13 per 100,000 person years and did not vary by gender or race. A bimodal distribution by age was noted with peak incidence rates in children (aged 5-14 years) and among older adults (aged 65-74 years in CBTRUS and 50-74 years in Los Angeles county). Survival information was available from GDVPTR and the National Cancer Data Base (NCDB), a hospital-based reporting system. In the NCDB, the 5-year survival rate was 80% and decreased with older age at diagnosis. Survival is higher among children and has improved in recent years.

CONCLUSIONS

Craniopharyngioma is a rare brain tumor of uncertain behavior that occurs at a rate of 1.3 per million person years. Approximately 338 cases of this disease are expected to occur annually in the United States, with 96 occurring in children from 0 to 14 years of age.

Pituitary magnetic resonance imaging in normal human volunteers: occult adenomas in the general population

OBJECTIVE

To determine the prevalence of focal lesions of the pituitary gland that suggest the presence of a pituitary adenoma in asymptomatic persons.

DESIGN

100 normal volunteers (70 women, 30 men; age range, 18 to 60 years old) were studied by high-resolution magnetic resonance imaging (MRI) of the pituitary gland before and after administration of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA).

SETTING

Occult pituitary adenomas are identified at autopsy in 3% to 27% of unselected asymptomatic patients. The frequency of incidental pituitary adenomas detected by MRI in normal persons is unknown.

MEASUREMENTS

The MRI scans from volunteers were randomly mixed with scans of 57 patients with Cushing disease and interpreted independently by three blinded reviewers.

RESULTS

Seven women (10%) and three men (10%) had focal areas of decreased signal intensity in the pituitary gland after administration of Gd-DTPA. The lesions ranged from 3 to 6 mm in greatest diameter and were diagnosed as pituitary adenomas by at least two of the three reviewers. When similar lesions were detected on MRI scans in patients with Cushing disease, the positive predictive value for identification of an adenoma at that site was 86%.

CONCLUSIONS

About 10% of the normal adult population have pituitary abnormalities on MRI scans that are compatible with the diagnosis of asymptomatic pituitary adenomas. Most pituitary adenomas remain asymptomatic and do not require treatment.

Incidence of pituitary adenomas in Northern Finland in 1992-2007

CONTEXT

Data on the incidence of pituitary adenomas (PAs) are scant and outdated. A population-based regional cohort with thorough case identification was used to evaluate the incidence of clinically detected PAs in the era of magnetic resonance imaging.

OBJECTIVE

The objective of the study was to describe the age- and sex-specific incidence of all PA subgroups, with data on incidentally found PAs, pituitary apoplexies, and time trends.

DESIGN, SETTINGS, AND PATIENTS

This was a retrospective descriptive analysis of PA patients diagnosed during 1992-2007 in Northern Finland (NFi).

MAIN OUTCOME MEASURE

World Health Organization 2000-standardized incidence rates (SIRs) of PAs per 100,000 were measured.

RESULTS AND CONCLUSION

The final cohort consisted of 355 PAs. The incidence rates of the Oulu University Hospital regional district were used as a reference to assess the applicability of our case finding over the rest of NFi. Incidence rates of all PA subgroups except microprolactinomas were statistically equal between these areas; thus, all presented SIRs are based on the NFi's cohort except Oulu University Hospital regional district-based prolactinomas and PAs overall. Overall SIR of PAs was higher (4.0 per 100,000) than in previous reports. Prolactinomas had the highest SIR: 2.2 per 100,000, followed by clinically nonfunctioning PAs (1.0) and GH-secreting (0.34), ACTH-secreting (0.17), and TSH-secreting (0.03) PAs. The gender-specific SIR was 2.2 per 100,000 in males and 5.9 per 100,000 in females. Pituitary apoplexy occurred as a presenting symptom in 11% of clinically nonfunctioning PA patients. The SIR of incidentally discovered PAs increased significantly from 1992-1999 to 2000-2007 (0.59 to 1.6, respectively; P < 0.01), which accounted for the perceived increasing trend in the overall SIR of PAs (3.8 to 4.2; P > 0.05).

Descriptive epidemiology of primary brain and CNS tumors: results from the Central Brain Tumor Registry of the United States, 1990-1994

The Central Brain Tumor Registry of the United States (CBTRUS) obtained 5 years of incidence data (1990-1994)--including reports on all primary brain and CNS tumors--from 11 collaborating state cancer registries. Data were available for 20,765 tumors located in the brain, meninges, and other CNS sites, including the pituitary and pineal glands. The average annual incidence was estimated at 11.5 cases per 100,000 person-years. The higher incidence of tumors in male patients (12.1 per 100,000 person-years) than in female patients (11.0 per 100,000 person-years) was statistically significant (P < 0.05); the higher incidence in whites (11.6 per 100,000 person-years) compared with blacks (7.8 per 100,000 person-years) was statistically significant (P < 0.05). The most frequently reported histologies were meningiomas (24.0%) and glioblastomas (22.6%). Higher rates for glioblastomas, anaplastic astrocytomas, oligodendrogliomas, anaplastic oligodendrogliomas, ependymomas, mixed gliomas, astrocytomas not otherwise specified, medulloblastomas, lymphomas, and germ cell tumors in male than in female patients were statistically significant (P < 0.05), with relative risks (RR) ranging from 1.3 to 3.4. Meningiomas were the only tumors with a significant excess in females (RR = 0.5). We noted higher occurrence rates in whites than in blacks for the following histologies: diffuse astrocytomas, anaplastic astrocytomas, glioblastomas, oligodendrogliomas, ependymomas, mixed gliomas, astrocytomas NOS, medulloblastomas, nerve sheath tumors, hemangioblastomas, and germ cell tumors, with RRs ranging from 1.5 to 3.4. Racial differences in occurrence rates were not observed for predominately benign meningiomas or pituitary tumors. This study represents the largest compilation of data on primary brain and CNS tumors in the United States. Standard reporting definitions and practices must be universally adopted to improve the quality and use of cancer registry data.

Incidental pituitary lesions in 1,000 unselected autopsy specimens

PURPOSE

To elucidate the frequency of false-positive results in imaging diagnoses of a functioning pituitary microadenoma, the authors studied various kinds of incidental lesions greater than 2 mm in diameter from a larger series of pituitary glands.

MATERIALS AND METHODS

One thousand pituitary glands were studied in a nonselected autopsy series. Most causes of death were acute diseases or accidents. Each gland was fixed in 10% formalin and was then cut horizontally into three or four pieces, which were prepared for usual light microscopy.

RESULTS

Of 178 glands found to have incidental lesions, 61 (34%) lesions were larger than 2 mm. Included were adenomas and hyperplasias (n = 20), Rathke cysts (n = 37), infarctions (n = 2), and hemorrhages (n = 2). Seventeen (74%) of 23 laterally localized lesions were adenomas, and 33 (87%) of 38 medially situated lesions were Rathke cleft cysts. These lesions were found in 5.8%-8.3% of subjects in every generation aged 30 years or older.

CONCLUSION

Incidental lesions should be considered a cause of false-positive findings (6.1%) when an imaging diagnosis is made of a functioning pituitary microadenoma.

Pituitary disease in MEN type 1 (MEN1): data from the France-Belgium MEN1 multicenter study

To date, data on pituitary adenomas in MEN type 1 (MEN1) still have to be evaluated. We analyzed the data of a large series of 324 MEN1 patients from a French and Belgian multicenter study. Data on pituitary disease were compared with those from 110 non-MEN1 patients with pituitary adenomas, matched for age, year of diagnosis, and follow-up period. Genetic analysis of the MEN1 gene was performed in 197 of the MEN1 patients. In our MEN1 series, pituitary disease occurred in 136 of 324 (42%), less frequently than hyperparathyroidism (95%, P < 0.001) and endocrine enteropancreatic tumors (54%, P < 0.01). Mean age of onset of pituitary tumors was 38.0+/-15.3 yr (range, 12-83 yr). Pituitary disease was associated with hyperparathyroidism in 90% of cases, with enteropancreatic tumors in 47%, with adrenal tumors in 16%, and with thoracic neuroendocrine tumors in 4%. Pituitary disease was the initial lesion of MEN1 in 17% of all MEN1 patients. MEN1 pituitary adenomas were significantly more frequent in women than in men (50% vs. 31%, P < 0.001). Among the 136 pituitary adenomas, there were 85 prolactinomas and 12 GH-secreting, 6 ACTH-secreting, 13 cosecreting, and 20 nonsecreting tumors. Eighty-five percent of MEN1-related pituitary lesions were macroadenomas (vs. 42% in non-MEN1 patients, P < 0.001), including 32% of invasive cases. Among secreting adenomas, hormonal hypersecretion was normalized, after treatment, in only 42% (vs. 90% in non-MEN1 patients, P < 0.001), with a median follow-up of 11.4 yr. No correlation was found between the type of MEN1 germ-line mutation and the presence or absence of pituitary adenoma. Our study, based on a large group of MEN1 patients, shows that pituitary adenomas occur in 42% of the cases and are characterized by a larger size and a more aggressive presentation than without MEN1.

The epidemiology of pituitary adenomas in Iceland, 1955-2012: a nationwide population-based study

OBJECTIVE

Pituitary adenomas (PA) are among the most common human neoplasms. To describe the epidemiology and assess the disease burden of clinically significant PAs, population-based studies are needed. Iceland has a small well-defined population. The aim of this study is to describe the epidemiology of PAs in Iceland over an expanded period of time.

DESIGN

This is a retrospective observational study, including all PAs diagnosed in Iceland from 1955 to 2012.

METHODS

Extensive clinical information was gathered in a database. Prevalence rates for all PA subtypes were calculated along with standardized incidence rates (SIR). Sex ratios and relationships with adenoma size, age, and symptoms were assessed.

RESULTS

We identified 471 individuals: 190 men and 281 women. Total prevalence in 2012 was 115.57/100, 000, prolactinomas were most prevalent (54.37/100, 000) followed by non-functioning adenomas (NFPAs) (42.32/100 ,000). Throughout the period, NFPAs were most common (43.0%) followed by prolactinomas (39.9%) and 11.3% had acromegaly and 5.7% Cushing's disease. Women are diagnosed younger with smaller adenomas. Total SIR has increased significantly and is now 5.8/100 000 per year.

CONCLUSION

In this nationwide study spanning six decades, we have confirmed PAs rising prevalence and incidence rates noted in recent studies. We demonstrated higher overall prevalence and incidence rates than ever previously recorded with an increasing predominance of NFPAs, which is not explained by incidental findings alone. There is a relationship with the introduction of imaging modalities, but the vast majority of patients are symptomatic at diagnosis. This underlines the importance of increased awareness, education, and appropriate allocation of resources for this growing group of patients.

Tumors of the nervous system and pituitary gland associated with atomic bomb radiation exposure

BACKGROUND

The risk of developing nervous system tumors following exposure to ionizing radiation is not well quantified. We characterized the incidence of nervous system tumors among atomic bomb survivors as a function of radiation dose.

METHODS

Tumors of the nervous system and pituitary gland diagnosed between 1958 and 1995 among 80 160 atomic bomb survivors were ascertained using the Hiroshima and Nagasaki tumor registries, medical records, and death certificates. Pathologists reviewed slides and medical records to provide histologic diagnoses. Poisson regression analyses were used to characterize radiation effects on tumor incidence, which are expressed as excess relative risk per sievert (ERR(Sv)). All statistical tests were two-sided.

RESULTS

A statistically significant dose-related excess of nervous system tumors was observed in the cohort (ERR(Sv) = 1.2, 95% confidence interval [CI] = 0.6 to 2.1). The highest ERR(Sv) was seen for schwannoma (4.5, 95% CI = 1.9 to 9.2). The risk for all other nervous system tumors as a group is also statistically significantly elevated (ERR(Sv) = 0.6, 95% CI = 0.1 to 1.3). Risk increases, although not statistically significant, were seen for meningiomas (ERR(Sv) = 0.6, 95% CI = -0.01 to 1.8), gliomas (ERR(Sv) = 0.6, 95% CI = -0.2 to 2.0), other nervous system tumors (ERR(Sv) = 0.5, 95% CI = <-0.2 to 2.2), and pituitary tumors (ERR(Sv) = 1.0, 95% CI = <-0.2 to 3.5). The dose-response relationships were linear. For nervous system tumors other than schwannoma, excess risks were higher for men than for women and for those exposed during childhood than for those exposed during adulthood.

CONCLUSIONS

A statistically significant dose response was observed for all nervous system tumors combined and for schwannoma considered separately, indicating that exposure to even moderate doses (i.e., <1 Sv) of radiation is associated with an elevated incidence of nervous system tumors.

Non-functioning pituitary adenoma database: a useful resource to improve the clinical management of pituitary tumors

OBJECTIVE

The long-term outcome of non-functioning pituitary adenoma (NFPA) patients is not clearly established, probably due to the low annual incidence and prolonged natural history of these rare tumors. The aim of this study was to evaluate clinical data at presentation and long-term post-surgery and radiotherapy outcome in a cohort of patients with NFPA.

DESIGN AND METHODS

A computerized database was developed using Access 2000 software (Microsoft Corporation, 1999). Retrospective registration of 295 NFPA patients was performed in seven Endocrinological Centers of North West Italy. Data were analyzed by STATA software.

RESULTS

The main presenting symptoms were visual defects (67.8%) and headache (41.4%) and the most frequent pituitary deficit was hypogonadism (43.3%), since almost all tumors were macroadenomas (96.5%). Surgery was the first choice treatment (98% of patients) and total debulking was achieved in 35.5%. Radiotherapy was performed as adjuvant therapy after surgery in 41% of patients. At the follow-up, recurrence occurred in 19.2% of patients without post-surgical residual tumor after 7.5 +/- 2.6 years, regrowth in 58.4% of patients with post-surgical remnant after 5.3 +/- 4.0 years and residue enlargement in 18.4% of patients post-surgically treated with radiotherapy after 8.1 +/- 7.3 years.

CONCLUSIONS

Our database indicates that the goal of a definitive surgical cure has been achieved during the last decade in a low percentage of patients with NFPA. This tumor database may help to reduce the delay between symptom onset and diagnosis, to assess prognostic parameters for the follow-up of patients with different risk of recurrence and to define the efficacy and safety of different treatments and their association with mortality/morbidity.

The epidemiology of prolactinomas

Prolactin-secreting tumors (prolactinomas), the most frequently occurring pituitary tumor, have a frequency that varies with age and sex. They occur most frequently in females aged 20 to 50 years old, at which time the female-to-male ratio is approximately 10:1. In the pediatric-adolescent age group, prolactinomas have a prevalence of 100/million population, and account for less than 2% of all intracranial tumors. Prolactinomas occur in approximately 30% of patients with multiple endocrine neoplasia type 1 and in this setting, they may be more aggressive than their sporadic counterparts. Patients with Carney complex or McCune-Albright syndrome may exhibit hyperprolactinemia due to a pituitary tumor derived from somatomammotropic cells that secrete both growth hormone and prolactin. Few familial cases of prolactinoma unrelated to MEN-1 are reported in literature.

The Epidemiology of Pituitary Adenomas

Pituitary adenomas are usually nonmalignant, but have a heavy burden on patients and health care systems. Increased availability of MRI has led to an increase in incidentally found pituitary lesions and clinically relevant pituitary adenomas. Epidemiologic studies show that pituitary adenomas are increasing in incidence (between 3.9 and 7.4 cases per 100,000 per year) and prevalence (76 to 116 cases per 100,000 population) in the general population (approximately 1 case per 1000 of the general population). Most new cases diagnosed are prolactinomas and nonsecreting pituitary adenomas. Most clinically relevant pituitary adenomas occur in females, but pituitary adenomas are clinically heterogeneous.

The incidence rate of pituitary adenomas in western Sweden for the period 2001-2011

OBJECTIVE

The number of studies on the incidence of pituitary adenomas (PAs) is limited. The aim of this study was to evaluate the standardised incidence rate (SIR) of PAs in western Sweden.

DESIGN, SUBJECTS AND METHODS

Data from adult patients diagnosed with PAs in 2001-2011, living in the Västra Götaland County, were collected from the Swedish Pituitary Registry (SPR). In addition, medical records on all patients diagnosed with PAs at the six hospitals in the region were reviewed. In total, 592 patients were included in the study.Age-SIR, given as rate/100 000 inhabitants (95% CI), was calculated using the WHO 2000 standard population as a reference.

RESULTS

The total SIR for PAs was 3.9/100 000 (3.6-4.3); 3.3/100 000 (2.9-3.7) for men and 4.7/100 000 (4.1-5.3) for women. In men, SIR increased with age, while in women SIR peaked at 25-34 years, mainly due to prolactinomas. Non-functioning PA (NFPA) was the most common PA (54%, 1.8/100 000 (1.6-2.0)) followed by prolactinomas (32%, 1.6/100 000 (1.3-1.9)), acromegaly (9%, 0.35/100 000 (0.25-0.45)), Cushing's disease (4%, 0.18/100 000 (0.11-0.25)) and TSH-producing PA (0.7%, 0.03/100 000 (0.00-0.05)). The proportion of macroadenomas for NFPA was 82%, prolactinomas 37%, GH-producing PA 77%, ACTH-producing PA 28% and TSH-producing PA 100%. The lifetime risk for PAs was 0.27% (0.24-0.31) in men and 0.29% (0.26-0.33) in women.

CONCLUSION

This study provides a reliable estimate on the overall incidence of PAs and confirms an increased incidence of PAs compared with studies conducted in the pre-magnetic resonance imaging era. The lower proportion of prolactinomas compared with previous studies is probably explained by the different criteria used.

Age-related and gender-related occurrence of pituitary adenomas

OBJECTIVE

To evaluate the various types of pituitary adenomas according to sex and age group. Few studies have attempted such an analysis, and most have focused on specific age groups, especially children. Recent data suggest that the frequency of different types of pituitary adenomas varies according to age and sex.

DESIGN

A retrospective review of the records of 2230 patients who underwent surgery for a pituitary adenoma at the University of California, San Francisco (UCSF), between January 1969 and June 1993.

METHODS

The distribution of tumours was analysed according to age at surgery, sex, and the clinical phenotype of the tumour. Age groups were defined as the decades of life.

RESULTS

Prolactinomas were the most common tumours (39%), followed by endocrine-inactive adenomas, growth-hormone-releasing adenomas, and adrenocorticotrophic hormone-releasing adenomas causing Cushing's disease; ACTH-releasing adenomas causing Nelson's syndrome and thyrotrophin (TSH)-releasing adenomas were rare. The female-to-male ratio differed considerably between the various adenoma types and between age groups. Prolactinomas, ACTH-releasing adenomas, and TSH-releasing adenomas occurred mostly in females; endocrine-inactive and GH-releasing adenomas occurred mostly in males. In older age groups, all adenoma types, except for endocrine-inactive adenomas, tended to assume a more balanced gender distribution. Among patients with prolactinomas, endocrine-inactive, ACTH-releasing, and to a lesser extent GH-releasing adenomas, the greatest discrepancy in gender distribution seemed to coincide with the peak occurrence of each tumour type. The peak occurrence was from the second to the fifth decade of life for prolactinomas and from the fourth to the eighth decade for endocrine-inactive adenomas. GH-releasing, ACTH-releasing, and TSH-releasing adenomas were more evenly distributed throughout the adult life span.

CONCLUSIONS

The frequency of pituitary adenomas varies greatly according to age and sex. The various adenoma types have their peak occurrence in distinctly different age groups and differ greatly in their female-to-male ratios. The female-to-male ratio for a given adenoma type varies greatly with age.

A survey of pituitary incidentaloma in Japan

OBJECTIVE

The development of computed tomography (CT) and magnetic resonance imaging (MRI) has resulted in the discovery of unsuspected endocrinologically silent pituitary masses (pituitary incidentalomas). The aim of this study was to perform a national survey on pituitary incidentalomas in order to establish an appropriate approach to them.

DESIGN AND METHODS

Five hundred and six patients with pituitary incidentalomas were obtained by questionnaire from March 1999 to May 2000 under the auspices of the Ministry of Health, Labor and Welfare in Japan. Two hundred and fifty-eight patients underwent surgery (surgical group), while 248 patients were followed up conservatively for a mean period of 26.9 Months (range 6-173 Months) (non-surgical group). Clinical and biochemical assessment, CT or MRI of the pituitary, and visual field testing by Goldman perimetry were assessed at baseline and 6 Months and Yearly thereafter.

RESULTS

Thirty-three patients with pituitary incidentalomas (13.3%) developed tumor enlargement during the mean follow-up period of 45.5 Months. Of 115 estimated non-functioning adenomas, 23 tumors (20.0%) increased during a mean follow-up period of 50.7 Months (range 10-173 Months), while 5 of 94 (5.3%) estimated Rathke's cysts increased in size during follow-up. Pituitary apoplexy occurred in one of 248 patients (0.4%).

CONCLUSIONS

Pituitary incidentalomas usually follow a benign course. We recommend transsphenoidal adenectomy for a solid mass attached to the optic chiasma estimated to be a pituitary adenoma by MRI. Other patients should be followed up by MRI every 6 Months for the first 2 Years, and then Yearly.

Endoscopic endonasal approach for pituitary adenoma: surgical complications in 301 patients

The authors investigate the complications of transnasal transsphenoidal endoscopic surgery in the treatment of 301 patients with pituitary adenomas. A retrospective analysis of complications in 301 patients submitted to transsphenoidal transnasal endoscopic surgery at the General Hospital of Fortaleza, Brazil between January 1998 and December 2009. The complications were divided in two groups: anatomical (oronasofacial, sphenoid sinus, intrasellar, suprasellar and parasellar) and endocrinological complications (anterior and posterior pituitary dysfunctions). We observed a total of 81 complications (26.9%) in our series. Anatomical complications occurred in 8.97% (27 cases): 8 CSF postoperative leaks (2.6%), 6 cases (1.9%) of delayed nasal bleeding, 5 cases (1.6%) of sphenoidal sinusitis, 3 cases (0.9%) of carotid artery lesion, 2 cases of meningitis (0.6%) and one case (0.3%) of each of the uncommon following complications: intrasella-suprasella hematoma, pontine hematoma and chiasmaplexy. Endocrinological complications occurred in 17.9% (54 cases): additional postoperative anterior lobe insufficiency in 35 cases (11.6%), and postoperative diabetes insipidus in 19 cases (6.3%). In our series, 3 cases of deaths (not directly related to the procedure) were also observed. Endoscopic transsphenoidal surgery represents an effective option for the treatment of patients with pituitary tumor. Complications still occur and must be reduced as much as possible. Successful endoscopic pituitary surgery requires extensive training in the use of an endoscope and careful planning of the surgery. Additional improvement can be expected with greater experience and new technical developments.

Epidemiology, clinical presentation and diagnosis of non-functioning pituitary adenomas

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are benign pituitary neoplasms that do not cause a hormonal hypersecretory syndrome. An improved understanding of their epidemiology, clinical presentation and diagnosis is needed.

METHOD

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

RESULTS

They account for 14-54% of pituitary adenomas and have a prevalence of 7-41.3/100,000 population. Their standardized incidence rate is 0.65-2.34/100,000 and the peak occurence is from the fourth to the eighth decade. The clinical spectrum of NFPAs varies from being completely asymptomatic to causing significant hypothalamic/pituitary dysfunction and visual field compromise due to their large size. Most patients present with symptoms of mass effect, such as headaches, visual field defects, ophthalmoplegias, and hypopituitarism but also hyperprolactinaemia due to pituitary stalk deviation and less frequently pituitary apoplexy. Non-functioning pituitary incidentalomas are found on brain imaging performed for an unrelated reason. Diagnostic approach includes magnetic resonance imaging of the sellar region, laboratory evaluations, screening for hormone hypersecretion and for hypopituitarism, and a visual field examination if the lesion abuts the optic nerves or chiasm.

CONCLUSION

This article reviews the epidemiology, clinical behaviour and diagnostic approach of non-functioning pituitary adenomas.

Radiologic characteristics and results of surgical management of Rathke's cysts in 43 patients

Although Rathke's cysts are a relatively common autopsy finding, rarely have they been reported as a clinical entity. Because of recent improvements in neuroradiological imaging, cystic intrasellar and suprasellar lesions are discovered often, leading to questions about proper management. Against this background, we reviewed the data from 43 patients with Rathke's cysts treated by one neurosurgeon over a 13-year period, and present the results here. The 43 patients had a mean age of 34 years, and 77% were female. Headache was the most common symptom, followed by galactorrhea, visual field loss, and hypopituitarism. Computed tomographic (CT) scans were reviewed in 20 cases, magnetic resonance (MR) images were reviewed in 15, and both CT and MR studies were reviewed in 5 cases. Although all Rathke's cysts were discrete and well-defined by both CT and MR imaging, the diversity of locations, CT attenuations, and MR signal intensity make it difficult to establish the diagnosis by radiological criteria. Forty patients underwent transsphenoidal surgery and three underwent craniotomy. There was one recurrence at 25 months requiring a second operation, and the mean follow-up period was 62 months. Seven patients had persistent headaches. For symptomatic lesions suspected to be Rathke's cysts, the recommended treatment is simple drainage of the cyst with biopsy of the wall, when this can be done safely. Follow-up imaging should be minimal for asymptomatic patients, and radiation therapy is not indicated.

Prevalence and incidence of pituitary adenomas: a population based study in Malta

Epidemiological data is important to correctly quantify the extent of disease and needed health care resources. The aim of the study was to establish the prevalence and incidence of pituitary adenomas (PAs) in the same well defined population, with in-depth analysis of the various subtypes. The design involved a retrospective cross-sectional analysis of PA patients diagnosed prior to 31 July 2011 for prevalence estimates and those diagnosed between July 2000 and July 2011 for incidence estimation. A thorough search for patients with PAs was carried out in central hospital registries including outpatients departments, surgical registries, radiological department and specialty clinic databases. Prevalence rates/100,000 and Standardised incidence ratios (SIR)/100,000/year were worked out. The respective prevalence rates and SIR for PAs overall were 75.7/100,000, and 4.27/100,000/year, for Prolactinomas 35.0/100,000 and 2.05/100,000/year, for nonfunctioning PA 25.9/100,000 and 1.79/100,000/year and for GH-secreting PAs 12.5/100,000 and 0.31/100,000/year. The overall prevalence for macroadenomas was 32.8/100,000 and SIR was 1.49/100,000/year. The prevalence rate in males for PAs overall was 46.3/100,000 and SIR was 2.08/100,000/year and in females 104.8/100,000 and SIR was 6.58/100,000/year. Females had a lower proportion of macroadenomas than males (29.5 vs. 75.0%; P < 0.001) and macroadenomas tended to present at a later age compared to microadenomas (48 vs. 34.5; P < 0.001). The highest SIR was reached in the 30-39 age group at 7.42/100,000/year. Our data confirm the considerable disease burden that PAs bear on health care resources. Males and females have similar prevalence and SIR rates for macroadenomas but there is a significant increase in SIR in females of child bearing age compared to males. These observations may have important implications in terms of the economic burden and need for early intervention.