Double pituitary adenomas: six surgical cases

Double pituitary adenomas: report of two cases and systematic review of the literature

Objective

Double pituitary adenomas (DPA) are a rare clinical condition, and our knowledge of them is limited. Missing the second lesion leading to incomplete biochemical remission after surgery is an important challenge in DPA management. This study aims to analyze independent prognostic factors in DPA patients and summarize clinical experiences to prevent surgical failure.

Methods

Two cases of DPA patients with Cushing's disease diagnosed and surgically treated at Peking Union Medical College Hospital are reported. A literature review was performed on the online database Pubmed, and 57 DPA patients from 22 retrieved articles were included. Demographic characteristics, endocrine manifestations, diagnostic methods, tumor size, and immunohistochemical features of 59 patients were analyzed. Binary logistic regression models were used to identify independent prognostic factors affecting postoperative biochemical remission.

Results

Among 59 DPA patients, the mean ± SD age was 43.64 ± 14.42 years, with 61.02% being female (n = 36). The most common endocrine manifestations were Cushing's syndrome (23/59, 38.98%) and acromegaly (20/59, 33.90%). The most prevalent immunohistochemical types were ACTH-immunopositive (31/118, 26.27%) and GH-immunopositive (31/118, 26.27%) tumors. Microadenomas (<1cm) were the most frequent in terms of tumor size (62/92, 67.39%). The detection rate for double lesions on 3.0T MRI was 50.00% (14/28), which significantly higher than 1.5T MRI (P = 0.034). Univariate analysis revealed that female, Cushing's syndrome and only single lesion detected by surgical exploration were associated with significantly worse prognosis (P<0.05). Multivariate analysis identified double lesion detected by surgical exploration (OR = 0.08, P = 0.003) and contiguous type tumor (OR = 0.06, P = 0.017) as independent protective factors for DPA patients.

Conclusions

The double lesion detected by surgical exploration is independently associated with a better prognosis for DPA patients. Comprehensive intraoperative exploration are crucial measures to avoid missing causative lesions.

A Collision Tumor of Pit-1/SF-1-positive Double Pituitary Adenoma and a Craniopharyngioma Coexisting with Graves' Disease

Double or multiple pituitary adenomas expressing different types of transcription factors and collision tumors of pituitary adenomas and craniopharyngiomas are rare. In this report, we present a case of pituitary adenoma of two different cell populations, Pit-1 and SF-1, and an adenoma and craniopharyngioma collision tumor with coexisting Graves' disease. The patient had a 16-mm pituitary tumor with pituitary stalk calcification and optic chiasm compression but no visual dysfunction. Based on hormonal profile results, the tumor in the sella was considered a nonfunctioning pituitary adenoma; nevertheless, the pituitary stalk was invaded by a different lesion, which was later confirmed to be a craniopharyngioma. Using an endoscopic endonasal approach, the pituitary adenoma was removed; however, a small remnant remained medial to the right cavernous sinus. Because the pituitary stalk lesion was isolated from the pituitary adenoma, it was preserved to maintain pituitary function. Three years after the initial surgery, the patient suffered from Graves' disease and was treated with antithyroid medications. However, the intrasellar residual and pituitary stalk lesions gradually increased in size. A second surgery was performed, and the residual intrasellar and stalk lesions were completely removed. As per the initial and second histopathologies, the pituitary adenoma comprised different cell groups positive for thyroid-(TSH) and follicle-stimulating hormones, and each cell group was positive for Pit-1 and SF-1. The pituitary stalk lesion was an adamantinomatous craniopharyngioma. We believe that TSH-producing adenoma was involved in the development of Graves' disease or that treatment for Graves' disease increased TSH-producing adenoma.

Multiple tumorous lesions of the pituitary gland

PURPOSE/OBJECTIVE

Multiple tumorous lesions in one pituitary gland are rare and mostly described in case reports. Their incidences and combinations are defined in larger collectives. Therefore, we analyzed our large collection for double tumors and combinations of tumors, cysts, and inflammation.

METHODS

The German Registry of Pituitary Tumors, including cases from 1990 to 2018, served as the database. Our collection comprises a total of 16,283 cases up until the end of 2018. Of these cases, 12,673 originated from surgical and 3,610 from autopsy material. All specimens were fixed in formalin and embedded in paraffin. The sections were stained with hematoxylin-eosin and PAS. Monoclonal (prolactin, TSH, FSH, LH, and α subunit) or polyclonal (GH and ACTH) antibodies were used to detect pituitary hormones in the lesions. Since 2017, antibodies against the transcription factors Pit-1, T-Pit, and SF-1 have been used in difficult cases. The criteria of the 2017 WHO classification have been basic principles for classification since 2018 (Osamura et al. 2017). For differentiation of other sellar tumors, such as meningiomas, chordomas, or metastases, the use of additional antibodies was necessary. For these cases, it was possible to use a broad antibody spectrum. Autopsy pituitaries were generally studied by H&E and PAS sections. If any lesions were demonstrated in these specimens, additional immunostaining was performed.

RESULTS

Multiple tumorous lesions with more than one pituitary neuroendocrine tumor (PitNET) respectively adenoma make up 1.4% (232 cases) in our collection. Within the selected cases, synchronous multiple pituitary neuroendocrine tumors (PitNETs) account for 17.3%, PANCH cases (pituitary adenoma with neuronal choristoma) for 14.7%, PitNETs and posterior lobe tumors for 2.2%, PitNETs and metastases for 5.2%, PitNETs and mesenchymal tumors for 2.6%, PitNETs and cysts for 52.2%, and PitNETs and primary inflammation for 6.0%. The mean patient age was 53.8 years, with a standard deviation of 18.5 years. A total of 55.3% of the patients were female and 44.7% were male. From 1990 to 2018, there was a continuous increase in the number of multiple tumorous lesions.

CONCLUSION

From our studies, we conclude that considering possible tumorous double lesions during surgeries and in preoperative X-ray analyses is recommended.

Growth hormone-releasing pituitary microadenoma overshaded by a macroadenoma: a case of double pituitary adenomas and review of the literature

OBJECTIVES

Double pituitary adenoma is a rare entity that can pose a significant challenge. The incidence of double or multiple pituitary adenomas is ∼1% in autopsy cases and 0.4-1.3% in surgical series. Its definition varies, including 'double adenomas' in the literature in contrast to 'multiple adenomas', which is more specific and suitable. While some authors require separating topographically unique tumours, others have used a looser definition of separate immunohistochemistry.

CASE PRESENTATION

We presented the case of a 26-year-old patient with recurrent carpal tunnel syndrome symptoms, with double pituitary adenomas secreting growth hormone (GH) and thyroid-stimulating hormone (TSH). To date, 89 patients have been reported in the literature with symptomatic carpal tunnel syndrome, but only five had GH-TSH secretion.

CONCLUSIONS

Double adenoma resection is of great importance for ensuring successful biochemical treatment. To ensure a successful operation, a careful preoperative 3T MRI examination is of great importance.

ASSESSMENT AND COMPARISON OF HORMONAL IMMUNOEXPRESSION AND THE CLINICAL PICTURE IN PATIENTS WITH PITUITARY ADENOMAS

Introduction

Symptoms related to hypersecretion of hormones in patients with pituitary adenomas do not always correlate with immunohistochemical staining results.

Objective

To evaluate the relationship between the pituitary adenomas hormone immunoexpressions and endocrine presentations.

Patients and methods

The clinical status and immunoexpression of 72 patients who underwent transsphenoidal surgery for pituitary adenomas were analyzed.

Results

Macroadenomas were diagnosed in 51 cases (70.84%), while microadenomas were found in 21 cases (29.16%). The 72 adenoma specimens were divided into 22 monohormonal, 21 plurihormonal, 21 immunonegative and 8 unreliable specimens. The positive immunohistochemical staining results occurred as follows: prolactin and growth hormone 25% each, adrenocorticotropic hormone 13.89%, thyroid-stimulating hormone 5.56%, leuteinizing hormone and follicle-stimulating hormone 12.5%, glycoprotein hormone alpha-subunit 22.22%. Statistically significant relationships between the immunohistochemical presentation and the preoperative diagnosis were found for prolactin and hyperprolactinemia, growth hormone and acromegaly and adrenocorticotropic hormone and Cushing's syndrome.

Conclusions

The lack of full concordance between the clinical presentations and immunohistochemical staining was mainly a result of the presence of nonfunctioning adenomas, plurihormonal adenomas and unreliable specimens. The morphometric method introduced in this study, utilizing the immunoexpression index, provided a very precise evaluation of pituitary adenomas pathology.

Double pituitary adenomas in a large surgical series

PURPOSE

To explore the incidence of double pituitary adenomas in a tertiary center for pituitary surgery and asses their clinical, imaging and histopathological features.

METHODS

The medical records of the patients operated on for pituitary tumors at the Department of Neurosurgery of Military Institute of Medicine in Warsaw, Poland between the years 2003 and 2018 were retrospectively analyzed. Among the 3270 treated patients, the diagnosis of double pituitary adenoma was established in 22 patients. Clinical, laboratory, detailed histopathological and diagnostics imaging data were collected and analyzed.

RESULTS

There were 21 cases of synchronous and one case of asynchronous double pituitary adenoma. The main clinical finding was acromegaly (12/22) followed by Cushing's disease (3/22). The diagnosis of synchronous double pituitary adenoma was suspected in the preoperative MRI in 11 patients. In the remaining patients the diagnosis of contiguous double pituitary adenoma was confirmed in the histopathological examination. There was no predilection for gender and the mean observation time was 74.2 months. In one case of Cushing's disease the occurrence of double pituitary adenoma led to the initial failure of achieving hormonal remission. One patient presented with double pituitary adenomas as a manifestation of Carney complex.

CONCLUSIONS

Double pituitary adenoma is a rare entity that can pose a significant challenge especially in the setting of Cushing's disease. Careful inspection of preoperative MRI and diagnostic work-up before transsphenoidal surgery and thorough histopathological microscopic examinations with immunohistochemical staining for all pituitary hormones is essential for establishing the diagnosis of double pituitary adenoma.

Double adenomas of the pituitary: an imaging, pathological, and clinical diagnostic challenge

Double and multiple adenomas of the pituitary are composed of two or more distinct tumors located in the same gland. They represent uncommon lesions measuring less than 1 cm, reported as having a low incidence in autopsies and occurring even more infrequently in surgical series. The histological diagnosis of double adenomas in surgical material is often extremely difficult, and confirmation requires immunohistochemistry and, occasionally, electron microscopy. Fragmented tissue material submitted for histology after transsphenoidal resection complicates the diagnosis. Difficulties in demonstrating double or multiple adenomas by imaging techniques contribute to diagnostic failure. Magnetic resonance imaging (MRI) techniques may disclose two separate adenomas located in the same pituitary gland. Intraoperative MRI and imaging ultrasonography, together with positron emission computed tomography, more accurately identify sites of residual tumors. These techniques might also detect postoperatively a residual tumor belonging to the second component of double adenoma. Double adenomas may also create extreme clinical diagnostic challenges. It is almost impossible to suspect functioning double adenomas with combined hormone secretion, each one secreting a different hormone, and distinguish them from an isolated plurihormonal adenoma, simultaneously secreting more than one hormone. Double adenomas may underlie surgical failure when one adenoma is removed while the other is left behind. Despite the low frequency of double adenomas, identification and resection of both of them is of major importance for the achievement of biochemical cure.

Synchronous Multiple Pituitary Neuroendocrine Tumors of Different Cell Lineages

We report clinicopathological features of a large series of synchronous multiple pituitary neuroendocrine tumors (PitNETs) of different cell lineages. Retrospective review of pathology records from 2001 to 2016 identified 13 synchronous multiple PitNETs from 1055 PitNETs classified using pituitary cell-lineage transcription factors, adenohypohyseal hormones, and other biomarkers. Clinical, radiological, and histopathological features of these tumors were reviewed. The series included seven females and six males. Mean age at diagnosis was 55.23 years (range 36-73). Imaging was unavailable for four patients; among the other nine, mean tumor size was 2.23 cm (range 0.9-3.9). Five patients had acromegaly, four had Cushing disease, and four had clinically non-functional tumors. Twelve had double PitNETs; one had a triple PitNET. The most common tumor type was corticotroph (n = 8; six densely and one sparsely granulated and one Crooke cell; three densely and one sparsely granulated were clinically silent), gonadotroph tumors (n = 8), and somatotroph tumors (n = 5; four sparsely granulated and one densely granulated somatotroph) were followed by lactotroph tumors (n = 4; all sparsely granulated), poorly differentiated Pit-1 lineage tumor (n = 1), and unusual plurihormonal tumor (n = 1). A 54-year-old man with Cushing disease had MEN1-driven Crooke cell and gonadotroph tumors. The triple pitNET consisted of a multilineage plurihormonal tumor associated with a gonadotroph and a sparsely granulated lactotroph tumor. The Ki67 (available from 10 specimens) ranged from 1 to 5% in individual tumors. Radiological and biochemical follow-up was available for 10 and 11 patients, respectively. Radiological tumor persistence/recurrence was identified in three patients with double PitNETs consisting of sparsely granulated lactotroph and gonadotroph tumors (n = 1), sparsely granulated somatotroph and silent corticotroph tumors (n = 1), and gonadotroph and silent corticotroph tumors (n = 1) with cavernous sinus invasion. Biochemical persistence was noted in four patients with double PitNETs consisting of sparsely granulated somatotroph and silent corticotroph tumors (n = 2), gonadotroph and Crooke cell tumors (n = 1), and densely granulated somatotroph and silent corticotroph tumors (n = 1). Multiple PitNETs represent about 1% of PitNETs and usually have hormone excess due to at least one tumor component. Clinical manifestations may be due to the minor component, especially in patients with Cushing disease. Invasive growth and aggressive histological subtypes predicted disease persistence/recurrence. This series also highlights the importance of routine application of pituitary cell lineage transcription factors along with hormones to distinguish and subtype multiple synchronous PitNETs.

Recurrences of Pituitary Adenomas or Second De Novo Tumors: Comparisons with First Tumors

BACKGROUND

Recurrences of pituitary adenomas are not so rare.

METHODS

In the German Registry of Pituitary Tumors, more than 12,000 surgical specimens were collected between 1967 and 2012, of which 312 patients with altogether 334 recurrences (n = 646 specimens) were included in our study.

RESULTS

The histopathology of 162 recurrent adenomas could be compared with the original tumor and 37 second recurrences could be compared with the first recurrence. Comparing the proliferation index (Ki-67) of the original and the first recurrent tumor (n = 162), we found an unchanged index in 43 cases (26%), whereas in 69 cases (43%) the index increased and in 50 cases (31%) it decreased. Comparing the first with the second recurrence (n = 37), we found an unchanged index in 8 cases (22%), an increased index in 15 cases (40%), and a decreased index in 14 cases (38%). The third recurrence showed an unchanged index in 1 case (20%), an increased index in 2 cases (40%), and a decreased index in 2 cases (40%). p53 was unchanged in recurrences in 44% of cases, increased in 33%, and decreased in 22%. In 4 cases, adenomas developed into adenomas with strongly increased proliferation (formerly atypical adenomas, now aggressive adenomas) for the first recurrence, and 9 recurrences became aggressive adenomas. A change of tumor type without change of the common transcription factor occurred in 82 cases.

CONCLUSIONS

A second independent de novo adenoma was present in 10 cases, probably due to changes of transcription factors.

Double pituitary adenomas are most commonly associated with GH- and ACTH-secreting tumors: systematic review of the literature

INTRODUCTION

Double adenomas in the pituitary gland are a rare occurrence. The ability to cure a hormone-producing adenoma with surgery is dependent on the ability to identify and completely remove the correct adenoma. The relative frequency of each subtype of hormone-secreting adenomas confirmed with magnetic resonance image (MRI), surgery and immunohistochemistry is not defined.

METHODS

Following PRISMA guidelines, we performed a systematic review of PubMed Central, Google Scholar, Scopus Database, Cochrane database and Science Research, using the key-words: "double pituitary adenomas", "multiple pituitary adenomas" and only papers where multiple or truly separate double pituitary adenomas were identified pre-surgically by MRI and/or confirmed by pathology/immunohistochemistry staining were included.

RESULTS

We reviewed papers from 1975 to 2016 and found 17 cases with two pituitary adenomas and 1 with three pituitary adenomas. The ages ranged from 22 to 67 years old, and there were twelve females and five males. Immunohistochemical staining showed that the most common double pituitary adenomas were growth hormone (GH)- followed by adrenocorticotropic (ACTH)-secreting.

CONCLUSION

Double pituitary adenomas are rare but most commonly found with GH- or ACTH-producing tumors. It is critical to remove all identified possible adenomas to achieve biochemical cure and clinicians should have heightened sensitivity in patients with acromegaly or Cushing's Disease.

Spontaneous pituitary adenoma occurring after resection of a Rathke's cleft cyst

Rathke's cleft cysts (RCC) are benign cystic lesions that originate from remnants of the epithelial lining of Rathke's pouch. RCC are known rarely to occur together with a concomitant pituitary adenoma. Here, we report a patient with a pituitary adenoma arising in the same location as a previously-resected RCC, 3 years post-operatively, and review the literature of "collision" sellar lesions. Consecutive transsphenoidal operations from a single-center between 2008 and 2016 were reviewed to identify patients with pituitary adenoma arising after surgical resection of RCC, and a systematic search of the literature was also performed to identify such patient reports, as well as reports of concomitant pituitary adenoma and RCC. Of 837 transsphenoidal operations from our own experience, one patient with pituitary adenoma occurring after RCC resection was identified and is reported here. A systematic review of the literature resulted in identification of 34 patients with concomitant RCC and pituitary adenoma and no incidents of pituitary adenoma occurring after resection of RCC. Concomitant occurrence of RCC and pituitary adenoma was more commonly diagnosed in women (61%), at a median age of diagnosis of 44 years. The RCC histological analysis in these patients consistently described ciliated columnar or cuboidal epithelium. Although rare, the presence of a new, pathologically-distinct lesions in the sella after prior surgical treatment, is possible. During post-operative monitoring, physicians should consider that what appears as a "recurrent" lesion may actually be growth of a new and entirely different lesion.

Isolated double adrenocorticotropic hormone-secreting pituitary adenomas: A case report and review of the literature

Only a few cases of double or multiple pituitary adenomas have previously been reported in the literature; however, isolated double adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas are even more rare. The present study reports a rare case of a 50-year-old female patient who presented with typical clinical features of Cushing's disease and was diagnosed with isolated double ACTH-secreting pituitary adenomas. Endocrinological examination revealed an ACTH-producing pituitary adenoma, and preoperative magnetic resonance imaging (MRI) demonstrated a microadenoma with a lower intensity on the right side of the pituitary gland. The patient underwent endoscopic endonasal transsphenoidal surgery, which revealed another pituitary tumor in the left side of the pituitary gland. The two, clearly separated, pituitary adenomas identified in the same gland were completely resected. Immunohistochemistry and pathology revealed that the clearly separated double pituitary adenomas were positive for ACTH, thyroid-stimulating, growth and prolactin hormones. Postoperatively, the levels of ACTH and cortisol hormone decreased rapidly. The case reported in the present study is considerably rare, due to the presence of a second pituitary adenoma in the same gland, which was not detected by preoperative MRI scan, but was noticed during surgery. Intraoperative evaluation may be important in the identification of double or multiple pituitary adenomas.

Multiple Pituitary Adenomas: A Systematic Review

PubMed, Scopus, and Web of Science Core Collection databases were systematically searched for studies reporting synchronous double or multiple pituitary adenomas (MPA), a rare clinical condition, with a vague pathogenesis. Multiple adenomas of the pituitary gland are referred to as morphologically and/or immunocytochemically distinct tumors that are frequently small-sized and hormonally non-functional, to account for the low detection rate. There is no general agreement on how to classify MPA, various criteria, such as tumor contiguity, immunoreactivity, and clonality analysis are being used. Among the component tumors, prolactin (PRL)-immunopositive adenomas are highly prevalent, albeit mute in the majority of cases. The most frequent clinical presentation of MPA is Cushing's syndrome, given the fact that in more than 50% of reported cases at least one lesion stains for adrenocorticotrophic hormone (ACTH). Plurihormonal hyperactivity may be diagnosed in a patient with MPA when more than one tumor is clinically active (e.g., ACTH and PRL) or in cases with at least one composite tumor (e.g., GH and PRL), to complicate the clinical scenario. Specific challenges associated with MPA include high surgical failure rates, enforcing second-look surgery in certain cases, and difficult preoperative neuroradiological imaging evaluation, with an overall sensitivity of only 25% for magnetic resonance imaging to detect distinct multiple tumors. Alternatively, minor pituitary imaging abnormalities may raise suspicion, as these are not uncommon. Postoperative immunohistochemistry is mandatory and in conjunction to electron microscopy scanning and testing for transcription factors (i.e., Pit-1, T-pit, and SF-1) accurately define and classify the distinct cytodifferentiation of MPA.

Isolated double pituitary adenomas: A silent corticotroph adenoma and a microprolactinoma

We report a 27-year-old woman with amenorrhea and galactorrhea with mildly elevated serum prolactin levels. Her MRI demonstrated a cystic macroadenoma in the left aspect of the sella and a small microadenoma in the right aspect of the sella. Endoscopic transsphenoidal resection of the tumors revealed two histologically distinct tumors. The left tumor was consistent with a silent corticotroph macroadenoma and the right tumor was a prolactin producing microadenoma. Isolated double pituitary adenomas that are clearly separated by normal pituitary gland tissue are extremely rare. The incidence is approximately 0.37-2.6%. The coexistence of double adenomas can pose diagnostic and management challenges for the pituitary neuroendocrine team.

Synchronous GH- and prolactin-secreting pituitary adenomas

Pituitary adenomas are usually solitary lesions. Rarely, patients may present with two distinct pituitary tumors. We report a case of synchronous secretory pituitary adenomas in a woman who initially presented with elevated prolactin levels. She was initially treated with cabergoline, but, after many years, she began developing symptoms consistent with acromegaly. Imaging revealed two distinct tumors within the pituitary gland. Endocrinological investigation confirmed acromegaly. At the time of surgery, two separate tumors were identified and resected. Pathological analysis demonstrated one tumor as a prolactinoma, and the other tumor as a GH-secreting adenoma. Postoperatively, her GH and IGF1 levels normalized, while the prolactin level remained slightly above normal. This case highlights that GH and prolactin level elevation is not always from co-secretion by the same adenoma.

A somatotropin-producing pituitary adenoma with an isolated adrenocorticotropin-producing pituitary adenoma in a female patient with acromegaly, subclinical Cushing's disease and a left adrenal tumor

A 67-year-old female with hypertension and impaired glucose tolerance was admitted to our hospital because of a typical acromegalic appearance, including large, thickened bulky hands and feet, and a large prominent forehead and tongue. She did not have a Cushingoid appearance, such as a moon-face, buffalo hump, purple striae or central obesity. The laboratory data revealed a serum GH level of 4.6 ng/mL and serum insulin-like growth factor-1 level of 811 ng/mL. The oral glucose tolerance test showed no suppression of the GH values. An endocrine examination showed a lack of circadian rhythmicity of ACTH and cortisol. Cortisol was not suppressed by a low dose of dexamethasone during the suppression test, but was suppressed by a high dose of dexamethasone. A radiological study revealed two isolated adenomas in the pituitary and a left adrenal tumor. These findings strongly suggested a diagnosis of acromegaly with subclinical Cushing's disease and a left adrenal incidentaloma. Transsphenoidal surgery was performed. Hematoxylin and eosin staining showed that the left and right pituitary adenomas were composed of basophilic and acidophilic cells, respectively. Immunohistochemical staining showed the left adenoma to be positive for ACTH and negative for GH. In contrast, the right adenoma was GH-positive and ACTH-negative. This is a rare case of independent double pituitary adenomas with distinct hormonal features. We also provide a review of the previously reported cases of double pituitary adenomas and discuss the etiology of these tumors.

Double, synchronous pituitary adenomas causing acromegaly and Cushing's disease. A case report and review of literature

Double pituitary adenomas are very rare and present up to 1 % of pituitary adenomas in unselected autopsy series and up to 2 % in large surgical series. We report a case of a 47-year-old man presented slight clinical features of acromegaly with 2 years duration. Endocrine evaluation confirmed active acromegaly and revealed adrenocorticotropin hormone-dependent hypercortisolemia. Preoperative magnetic resonance imaging of the pituitary demonstrated clearly separated double microadenomas with different intensity. The patient underwent transsphenoidal surgery and both tumors were completely removed and were fixed separately. The histological and ultrastructural examination confirmed coincidence of the double, clearly separated pituitary adenomas in one gland. Postoperative function of the hypothalamo-hypophyseal axis was normalized. We conclude from this case and a literature review that double endocrinologically active pituitary adenomas leading to acromegaly and Cushing's disease may occur. Additionally, a review of the literature regarding multiple pituitary adenomas has also been performed.

Double pituitary adenomas

Double pituitary adenomas represent up to 2.6 % of pituitary adenomas in large surgical series and up to 3.3 % of patients with Cushing's disease have been found to have double or multiple pituitary adenomas. We report the case of a 60-year-old male patient whose medical history began in 2002 with erectile dysfunction; hyperprolactinemia was found and MRI showed a 6-mm area of delayed enhancement in the lateral portion of the right pituitary lobe. Treatment with cabergoline was started with normalization of prolactin levels; the following MRI, performed in 2005 and 2008, showed shrinkage of the pituitary lesion. In 2005, the patient began to manifest weight gain, hypertension, and facial plethora, but no further evaluations were done. In January 2010, the patient came to our attention and underwent multiple tests that suggested Cushing's disease. A new MRI was negative. Bilateral inferior petrosal sinus sampling showed significant pituitary-to-peripheral ratio and, in May 2010, the patient underwent exploratory pituitary surgery with evidence of a 1-2-mm white-coloured midline area compatible with pituitary adenoma that was surgically removed. Post-operatively, the patient's clinical conditions improved with onset of secondary hypoadrenalism. The histologic examination confirmed a pituitary adenoma (immunostaining was found to be positive for ACTH and negative for prolactin). We report the case of an ACTH-producing microadenoma metachronous to a prolactin secreting microadenoma although not confirmed histologically, shrunk by medical treatment. A review of data in the literature regarding double or multiple pituitary adenomas has also been done.

Sellar collision tumor involving pituitary gonadotroph adenoma and chondroma: a potential clinical diagnosis

We report on a 74-year-old male patient who presented with progressive neuroophthalmologic symptoms soon after the administration of a long-acting gonadotropin-releasing hormone agonist for treatment of a prostate cancer. Imaging revealed a destructively growing and extensively calcified sellar mass inconsistent with a pituitary adenoma. A transseptal transsphenoidal tumor mass reduction yielded a histological diagnosis of a collision tumor comprised of a gonadotroph adenoma intermingled with osteochondroma. We discuss a potential causal relationship between the administration of the long-acting gonadotropin-releasing hormone agonist and the sudden appearance of the previously unsuspected sellar lesion. Although the association of these two tumors is very likely coincidental, the possibility of causal relationship is addressed.

A double pituitary adenoma presenting as a prolactin-secreting tumor with partial response to medical therapy. Case report

Double pituitary adenomas are difficult to recognize pre-operatively as only a single mass may be appreciated on imaging. We present herein a giant prolactin-secreting pituitary adenoma in a middle-aged man that had responded partially to dopamine agonist therapy. The excised specimen demonstrated a double adenoma. The prolactin-producing one displayed the expected morphological changes resulting from medical therapy, while the other, a gonadotroph adenoma, did not. The failure of tumor shrinkage can be attributed to the presence of a double adenoma, a previously unreported cause of failure of medical therapy in prolactinoma.

Prevalence of double pituitary adenomas in a surgical series: Clinical, histological and genetic features

BACKGROUND

The term double pituitary adenomas (DPA) is usually referred to those rare lesions showing two distinct cellular components. Genetic background may sustain the proliferation of more than one cell at the same time but no information is available on the presence of aip mutations in these patients.

AIM

We report the prevalence and the endocrinological, neuroradiological, histopathological and genetic features of DPA detected in a large surgical series. The contribution of pituitary transcription factor immunostains in DPA was also evaluated.

SUBJECTS AND METHODS

One-hundred-forty-four patients undergoing surgery for tumors of the sellar region were evaluated. Histopathology, immunohistochemistry and the mutational analysis for the entire coding region of the AIP and MEN1 genes were performed.

RESULTS

One-hundred-seventeen patients out of 144 had a pituitary adenoma. DPA was found in 3 (2.6%) out of 117 patients with pituitary adenoma. Immunohistochemistry and transcription factors analysis demonstrated two not yet described histotype associations in DPA. The coexistence of somatotroph-lactotroph and silent mammosomatotroph histotype in 1 case and the coexistence of sparsely granulated lactotroph and null cell adenomas in the remaining two cases were first identified. Sequencing data for the coding region of the aip and the menin gene resulted in wild type sequences in all patients with DPA.

CONCLUSIONS

The prevalence of DPA observed in our unselected surgical series is not negligible (2.6%). Furthermore, the evaluation of the treatment outcome would suggest that the clinical management of DPAs requires a careful diagnostic approach and follow- up.

O-methylguanine-DNA methyltransferase immunoexpression in a double pituitary adenoma: case report

OBJECTIVE

Double pituitary adenomas in surgical cases are rarely reported. The incidence in published surgical specimens ranges from 0.4% to 1.3%. We present a treatment dilemma of a double adenoma that had differential O-methylguanine-DNA methyltransferase (MGMT) reactivity.

CLINICAL PRESENTATION

A 48-year-old man presented with acromegaly and a recurrent pituitary adenoma. He had elevated growth hormone (GH) and elevated insulin-like growth factor blood levels and hyperprolactinemia.

INTERVENTION

Subtotal transsphenoidal resection was performed. Morphologic examination disclosed 2 histologically distinct tumors, including a GH adenoma and a prolactin adenoma. Immunohistochemistry revealed Ki-67 labeling indices of 1% and 2%, respectively. Of significant note was MGMT immunopositivity in the GH adenoma and lack of staining in the prolactin adenoma.

CONCLUSION

This is the first clinical instance in which MGMT was assessed in double adenomas of the pituitary. The 2 tumors showed significant differences in reactivity that could impact chemotherapeutic management. The adenomas underwent recurrence, a feature that reflects their invasive nature and the possibility that chemotherapeutic intervention may be required in the future. Response to temozolomide use is anticipated with respect to the prolactin adenoma but would likely not benefit the GH cell adenoma of our patient.

Cushing's disease due to double pituitary ACTH-secreting adenomas: the first case report

Double pituitary adenomas are rare occurrences in autoptical, surgical and neuroradiological series and are mostly due to non-functioning pituitary adenomas, GH-secreting and prolactin-secreting adenomas. ACTH secreting tumours are more rare and, to our knowledge, two distinct ACTH-producing adenomas within the same pituitary have never been reported. We herewith describe a 56 year old woman with Cushing' s disease due to two clearly distinct ACTH-secreting pituitary adenomas. She presented with signs and symptoms of hypercortisolism and hormonal testing was indicative for pituitary-dependent Cushing' s syndrome. Sellar MRI visualized an asymmetric pituitary gland with suspect lesions in both the right and the left pituitary lobes. Both lesions were removed during transsphenoidal surgery and remission of hypercortisolism ensued. Pathology confirmed the existence of two distinct adenomas located in different sites in the gland. Both presented ACTH immunoreactivity but displayed distinct morphological features. Our case indicates that double ACTH-secreting pituitary adenomas may occur in patients with Cushing' s disease. Careful radiological, surgical and pathological examination is necessary to recognize this condition and avoid surgical failure.

Collision sellar lesions: experience with eight cases and review of the literature

The concomitant presence of a pituitary adenoma with a second sellar lesion in patients operated upon for pituitary adenoma is an uncommon entity. Although rare, quite a great variety of lesions have been indentified coexisting with pituitary adenomas. In fact, most combinations have been described before, but an overview with information on the frequency of combined pathologies in a large series has not been published. We present a series of eight collision sellar lesions indentified among 548 transsphenoidally resected pituitary adenomas in two Neurosurgical Departments. The histological studies confirmed a case of sarcoidosis within a non-functioning pituitary adenoma, a case of intrasellar schwannoma coexisting with growth hormone (GH) secreting adenoma, two Rathke's cleft cysts combined with pituitary adenomas, three gangliocytomas associated with GH-secreting adenomas, and a case of a double pituitary adenoma. The pertinent literature is discussed with emphasis on pathogenetic theories of dual sellar lesions. Although there is no direct evidence to confirm the pathogenetic relationship of collision sellar lesions, the number of cases presented in literature makes the theory of an incidental occurrence rather doubtful. Suggested hypotheses about a common embryonic origin or a potential interaction between pituitary adenomas and the immune system are presented.

Collision tumors of the sella: craniopharyngioma and silent pituitary adenoma subtype 3: case report

Collision tumors of the sella turcica are rare and consist mainly of more than one type of pituitary adenoma, usually a corticotropin- and a prolactin-producing adenoma. The association of a craniopharyngioma and a pituitary adenoma is rare. Herein, we report the first case of an association between craniopharyngioma and silent pituitary adenoma subtype 3. It involved a 12-year-old boy who underwent a frontal craniotomy with surgical removal of a calcified sellar tumor. Histology revealed an adamantinomatous craniopharyngioma; however, by electron microscopy, there was conclusive evidence of adenoma cells showing the ultrastructural features of silent pituitary adenoma subtype 3. Endocrine and neuroimaging as well as detailed immunohistochemical and ultrastructural studies were undertaken. The literature is also reviewed.

Preoperative identification of clearly separated double pituitary adenomas

OBJECTIVE

Double pituitary adenomas are extremely rare. They can be divided into contiguous and clearly separated types. Most contiguous tumours are surgically removed as one tumour and the co-existence of different adenoma types can be confirmed by histological methods. In contrast, detailed preoperative neuroimaging studies can suggest the co-existence of separated multiple adenomas. In patients with multiple adenomas, surgical failure may result when one adenoma is missed during surgery. Among 600 surgical cases we encountered four patients with clearly separated double pituitary adenomas; all were highly suspect on preoperative MRI studies.

PATIENTS AND RESULTS

All four patients manifested acromegalic symptoms; one patient also exhibited hyperprolactinemia and two had familial pituitary adenomas unrelated to multiple endocrine neoplasia type I (MEN-1). All underwent transsphenoidal surgery and histology confirmed the diagnosis of GH-producing plus gonadotroph adenoma in two cases and of two GH-producing adenomas each in the other two patients.

CONCLUSION

Although the pathogenesis of our double adenomas remains unknown, genetic abnormalities may be involved because two patients had familial pituitary adenomas unrelated to MEN-1. When preoperative MRI is suggestive of double adenomas, careful surgical exploration is necessary to avoid missing the other adenoma because the risk of surgical failure is high, especially in patients with functioning adenomas.

Somatotroph and Corticotroph Pituitary Adenoma (Double Adenoma) in a Cat with Diabetes Mellitus and Hyperadrenocorticism

A 9-year-old castrated male European shorthair cat with insulin-resistant diabetes was referred with the preliminary diagnosis of pituitary-dependent hyperadrenocorticism, based on measurements of urinary corticoids. Further studies revealed not only resistance of plasma concentrations of cortisol, adrenocorticotropic hormone (ACTH) and alpha-melanocyte-stimulating hormone (alpha-MSH) to suppression by a low dose of dexamethasone, but also elevated plasma concentrations of growth hormone (GH) and insulin-like growth factor I (IGF-I). Pituitary imaging with dynamic contrast-enhanced computed tomography demonstrated an enlarged pituitary gland and an adenoma. The cat underwent trans-sphenoidal hypophysectomy after which the insulin resistance disappeared. On histopathological and immunocytochemical examination of the surgical specimen a double adenoma was found, consisting of a corticotroph adenoma and a somatotroph adenoma separated by unaffected pituitary tissue.

Pituitary macroadenoma secreting thyrotropin and growth hormone: remission of bihormonal hypersecretion in response to lanreotide therapy

We report a case of mixed TSH- and GH-secreting pituitary adenoma in a 60-year-old female patient. She presented with bitemporal hemianopsia and large invasive pituitary macroadenoma. Blood hormone levels determinations revealed elevated thyroid hormones, TSH, and IGF-1 with a relatively low GH. The patient had a mild acromegalic appearance but did not display signs of thyrotoxicosis or goiter. She underwent two pituitary surgical procedures followed by radiotherapy, but despite treatment was still hormonally active. Pathological examination of the resected tumor immunostained positively for both TSH and GH. The patient was subsequently treated with injections of lanreotide, a depot long-acting somatostatin analog, resulting in suppression of blood TSH, thyroid hormones, alpha-subunits, GH and IGF-1.

Double pituitary lesions in three patients with Cushing's disease

Double pituitary adenomas are rare in surgical specimens and the most common clinical feature in reported patients has been acromegaly. We report 3 cases of double pituitary lesions in patients who presented with Cushing's disease. In a 22-year-old man (case 1) with delayed puberty and low testosterone levels, mild hyperprolactinemia was diagnosed and treated with dopamine agonist therapy that reduced the prolactin (PRL) levels to normal. Over a 1-year period Cushing's disease developed gradually and was confirmed with classical endocrine testing. In a 27-year-old woman (case 2) who initially presented with severe depression and morbid obesity there was a gradual onset of Cushing's disease; initially she had minimally elevated serum PRL. In a 33-year-old woman (case 3) there was a 2-year history of Cushing's disease characterized by hirsutism, hypertension and weight gain; serum PRL was normal. Magnetic resonance imaging in all 3 patients revealed a microadenoma that was successfully removed by transsphenoidal pituitary surgery. Histology and immunocytochemistry in case 1 and case 3 revealed a corticotroph cell adenoma and a PRL cell adenoma in separate areas of the pituitary. In case 3 the PRL cell adenoma was "silent" but in case 1 the PRL cell adenoma may have been the cause of the mild hyperprolactinemia. In case 2 nodular corticotroph hyperplasia was the cause of Cushing's disease and a "silent" PRL cell adenoma was also identified. We conclude from these cases and a literature review that double pituitary lesions may occur in patients with Cushing's disease. The corticotroph part of the double lesion may consist of a corticotroph cell adenoma or, as reported in this study, of corticotroph nodular hyperplasia. The counterpart of the double lesion may consist either of a "silent" PRL cell adenoma or a functional PRL cell adenoma causing hyperprolactinemia.