Ectopic ACTH-secreting pituitary adenoma of the sphenoid sinus: case report of endoscopic endonasal resection and systematic review of the literature

Double Pituitary Adenomas in Patients With Cushing's Disease

Background and objective Double and multiple pituitary adenomas (PAs) are discovered in 2.6-3.3% of patients with Cushing's disease and in approximately 1% of autopsies. Undiagnosed and unremoved second PA may be the cause of unsuccessful surgical treatment of Cushing's disease. In this study, we aimed to describe our experience with the detection and treatment of patients with double PAs. Methods All patients in our series underwent transsphenoidal surgery (TSS) with endoscopic and neuronavigation assistance. Before 2017, we completely relied on MRI findings while planning surgery. From 2017 onwards, a broad revision of the sella turcica was conducted during surgeries regardless of the MRI data. Results Overall, 81 patients were included in the study: 51 before 2017 and 30 in 2017 after. In the pre-2017 group of patients, three out of 51 had double adenomas, and all of them were seen on MRI images. We encountered four more double PAs during the next period. Only two of them had been predicted by MRI. The remission rate was higher after 2017 and amounted to 90% (27 out of 30 patients). In contrast, before the implementation of total revision (pre-2017), our success rate was 82% (42 out of 51 cases). Both neoplasms in cases of double PAs yielded similar histological and immunohistochemical (IHC) features but were consistent with multiple PAs. Conclusions Although the improvement in our results in recent years cannot be clearly attributed to a targeted search for the second microadenoma, we still recommend performing a broad inspection of the sella turcica after the excision of the pituitary microadenoma regardless of preoperative MRI data.

Ectopic invasive ACTH-secreting pituitary adenoma mimicking chordoma: a case report and literature review

BACKGROUND

Ectopic pituitary adenoma (EPA) is defined as a special type of pituitary adenoma that originates outside of the sellar region, is extra- or intra-cranially located, and without connection to normal pituitary tissue. EPA is extremely rare, with most cases presented as case reports or small case series. Due to nonspecific symptoms and laboratory indicators, the preoperative diagnosis, treatment and management for EPA remain challenging.

CASE PRESENTATION

Here, we report the imaging phenotype and pathological findings of a case of invasive EPA in a 47-year-old woman. A preoperative non-contrast CT scan revealed a 5.8 × 3.6 × 3.7 cm soft tissue mass located in the sphenoid sinus and clivus. MRI showed an ill-defined solid mass with heterogeneous signals on T1-weighted and T2-weighted images. The mass displayed infiltrative growth pattern, destroying bone of the skull base, invading adjacent muscles and encasing vessels. The patient underwent partial tumor resection via transsphenoidal endoscopic surgery. Pathological examination led to diagnosis of ectopic ACTH-secreting pituitary adenoma. Post-surgery, the patient received external beam radiotherapy.

CONCLUSION

EPA with invasive growth pattern has rarely been reported. The imaging phenotype displays its relationship to the pituitary tissue and surrounding structures. Immunohistochemical examination acts as a crucial role in differentiating EPA from other skull base tumors. This case report adds to the literature on EPA by summarizing its characteristics alongside a review of the literature.

Clinical and radiological presentation of parasellar ectopic pituitary adenomas: case series and systematic review of the literature

PURPOSE

Parasellar ectopic pituitary adenomas (pEPAs) are extremely rare tumors located out of the sella turcica. PEPAs are heterogeneous entities in terms of anatomical localization and secretion of anterior pituitary hormones.

METHODS

Multicenter retrospective study. Clinical charts' consultation of patients diagnosed with parasellar lesions, to identify all subjects fulfilling the diagnostic criteria of parasellar EPAs. Systematic review of the literature focused on the medical management of prolactin-secreting pEPAs and on the prevalence of radiological bone invasion in pEPAs.

RESULTS

We identified four cases of pEPAs: (1) 54-year-old female with a prolactin-secreting suprasellar EPA successfully treated with cabergoline; (2) 74-year-old male with a non-functioning EPA of the sphenoidal sinus treated with endoscopic transsphenoidal surgery; (3) 75-year-old female with a giant lesion of the skull base (maximum diameter 7.2 cm) diagnosed as a non-functioning EPA after biopsy; (4) 49-year-old male with a silent corticotroph EPA of the sphenoidal sinus and clivus. Three out of four cases had radiological evidence of invasion of the surrounding bone structures. A systematic review of the literature highlighted that medical therapy can be effective in prolactin-secreting pEPAs. Overall, we found mention of local invasiveness in 65/147 cases (44.2%), confirmed by radiological signs of bone invasion/erosion.

CONCLUSION

Our experience confirms the heterogeneity of pEPAs in terms of clinical and radiological presentation, as well as hormone secretion. PEPAs show a high frequency of radiological bone invasion, though similar to that of sellar pituitary adenomas. Although extremely rare, pEPAs need to be considered in the differential diagnosis of parasellar lesions.

MRI-negative Cushing's Disease: Management Strategy and Outcomes in 15 Cases Utilizing a Pure Endoscopic Endonasal Approach

BACKGROUND

Cushing's disease (CD) is among the most common etiologies of hypercortisolism. Magnetic resonance imaging (MRI) is often utilized in the diagnosis of CD, however, up to 64% of adrenocorticotropic hormone (ACTH)-producing pituitary microadenomas are undetectable on MRI. We report 15 cases of MRI negative CD who underwent surgical resection utilizing a purely endoscopic endonasal approach.

METHODS

Endoscopic endonasal transsphenoidal surgery (EETS) was performed on 134 CD cases by a single surgeon. Fifteen cases met inclusion criteria: no conclusive MRI studies and no previous surgical treatment. Data collected included signs/symptoms, pre- and post-operative hormone levels, and complications resulting from surgical or medical management. Data regarding tumor diameter, location, and tumor residue/recurrence was obtained from both pre- and post-operative MRI. Immunohistochemistry was performed to assess for tumor hormone secretion.

RESULTS

Aside from a statistically significant difference (P = 0.001) in histopathological results between patients with negative and positive MRI, there were no statistically significant difference between these two groups in any other demographic or clinical data point. Inferior petrosal sinus sampling (IPSS) with desmopressin (DDAVP®) administration was performed on the 15 patients with inconclusive MRIs to identify the origin of ACTH hypersecretion via a central/peripheral (C/P) ratio. IPSS in seven, five and three patients showed right, left, and central side lateralization, respectively. With a mean follow-up of 5.5 years, among MRI-negative patients, 14 (93%) and 12 patients (80%) achieved early and long-term remission, respectively. In the MRI-positive cohort, over a mean follow-up of 4.8 years, 113 patients (94.9%) and 102 patients (85.7%) achieved initial and long-term remission, respectively.

CONCLUSIONS

Surgical management of MRI-negative/inconclusive Cushing's disease is challenging scenario requiring a multidisciplinary approach. An experienced neurosurgeon, in collaboration with a dedicated endocrinologist, should identify the most likely location of the adenoma utilizing IPSS findings, followed by careful surgical exploration of the pituitary to identify the adenoma.

Case Report and Literature Review: Ectopic Thyrotropin-Secreting Pituitary Adenoma in the Suprasellar Region

Ectopic thyrotropin-secreting pituitary adenoma (ectopic TSH-oma) is a rare disorder that is easily misdiagnosed in clinical work. We report one patient who presented with hyperthyroidism and a suprasellar mass. In this case, preoperative diagnosis of suprasellar ectopic thyrotropin-secreting pituitary adenoma was challenging. A literature review revealed that a total of 11 patients with ectopic TSH-oma were previously reported, and only our one case was diagnosed in the microadenoma stage. Most of the patients with TSH-oma or ectopic TSH-oma were middle-aged. We described ectopic TSH-oma in a child at length. We recommend that ectopic TSH-oma should be considered in the differential diagnosis of thyrotoxicosis syndrome to achieve an accurate, early diagnosis. The somatostatin suppression test and imaging examinations, such as magnetic resonance imaging and positron emission tomography/magnetic resonance imaging, could contribute to the diagnosis. Once the diagnosis was highly suspected, tumor resection could achieve a satisfying long-term outcome in ectopic TSH-oma.

Ectopic pituitary adenomas: clinical features, diagnostic challenges and management

PURPOSE

Ectopic pituitary adenomas (EPAs) are extremely rare pituitary adenomas located outside the sella turcica without any connection with intrasellar components. This study aims to review all the reported cases to date and describe the clinical characteristics of EPAs.

METHODS

In a retrospective chart review, 14 patients were identified with EPAs in our hospital. A literature review was performed, and 166 cases in the literature met the criteria. Clinical data were analyzed.

RESULTS

Of 180 patients with EPAs, the mean age at diagnosis was 45.4 years, and 66.5% of the patients were females. EPAs were mainly located in the sphenoid sinus (34.4%) and suprasellar region (25.6%), followed by the clivus (15.6%), cavernous sinus (13.3%) and nasopharynx (5.6%). Adrenocorticotropic hormone (ACTH)-secreting (38.9%) and nonfunctioning (27.2%) adenomas were predominant. Patients with suprasellar EPAs were more likely to present menstrual disorders and visual changes, while patients with clival EPAs were more likely to suffer from headaches. EPAs in the cavernous sinus and suprasellar space were more likely to be initially misdiagnosed as a suspicious intrasellar mass on imaging examination. The complete tumor resection rates for EPAs in the sphenoid sinus, suprasellar region, clivus, cavernous sinus and nasopharynx were 72.3%, 88.6%, 45.0%, 73.3% and 88.9%, respectively.

CONCLUSIONS

EPA clinical characteristics varied across different tumor locations and hormone-secreting types. In addition to comprehensive hormone evaluation and careful review of imaging data, nuclear medicine and surgical biopsy should also be considered when facing differential difficulty. EPA management should be individualized.

Diagnosis and Surgical Management of Exophytic Suprasellar Pituitary Adenoma Extending Over the Diaphragma Sellae and Mimicking Craniopharyngioma: A Case Report

Pituitary adenomas developing from the lateral surface of the pituitary gland are referred to as exophytic pituitary adenomas. When an exophytic pituitary adenoma extends into the suprasellar region, the tumor exhibits an atypical growth pattern that makes it difficult to distinguish it from craniopharyngiomas or other parasellar lesions on MRI.

A 53-year-old woman who presented with general malaise and visual disturbances was diagnosed with a brain tumor. MRI showed a suprasellar tumor presenting as superior lobulation with reticular enhancement and partial calcification. Subsequently, endoscopic transsphenoidal surgery was performed on the patient. The suprasellar tumor was found to originate from the superior surface of the normal pituitary gland and it extended into the supra-diaphragm region. Subtotal tumor resection was achieved, and her clinical symptoms subsequently improved.

Exophytic suprasellar pituitary adenomas (SPAs) are extremely rare and may be mistaken for ectopic SPAs in some cases. Contrast-enhanced fast imaging employing steady-state acquisition (CE-FIESTA) can clearly depict the connection between an exophytic SPA and the normal pituitary gland via a diaphragma sellae defect. During surgery, it was seen that the exophytic SPA and anterior lobe of the pituitary gland connected with each other directly. The tumor originated from the superior surface of the pituitary gland and extended into the supra-diaphragm region. These findings clearly confirmed the difference between exophytic SPAs and ectopic SPAs. In surgical management, an exophytic SPA needs careful consideration for resecting the tumor from encased surrounding structures without vascular and nerve injury. Ultrasonic aspiration devices may be useful for safely resecting the tumor from important structures due to tissue selection.

Exophytic SPAs are distinguished from ectopic SPAs with respect to the direct connection between the tumor and the normal pituitary gland. These findings can be clearly depicted using CE-FIESTA and should be confirmed during surgery. Clinicians should be aware of the risk that exophytic SPA may extend into the supra-diaphragm region and of the difficulties of resecting the tumor encasing surrounding structures in the suprasellar region.

Long-term follow-up for ectopic ACTH-secreting pituitary adenoma in a single tertiary medical center and a literature review

BACKGROUND

Ectopic ACTH-secreting pituitary adenoma (EAPA) are a rare cause of Cushing's disease. Due to the lack of consensus and experience in terms of the diagnosis and treatment of EAPAs, preoperative identification and optimal treatment remain challenging.

PURPOSE

To investigate the characteristics of EAPAs and offer some proposals for the diagnosis and management of this uncommon disease, the EAPA patients admitted to our center and all of the EAPA cases reported in the literature were reviewed.

METHODS

In a retrospective electronic medical chart review, 6 patients (0.39%) with EAPAs were identified from 1536 consecutive patients who were admitted to our hospital with a diagnosis of Cushing's syndrome between January 2000 and August 2019. A literature review was performed on the online databases PubMed and EMBASE, and 52 cases conformed to the criteria. The data regarding biochemical tests, imaging examinations and follow-ups were analyzed.

RESULTS

The mean age of patients with EAPAs was 37.7 years old, and an obvious female predominance (3.5: 1) was demonstrated. The most common location of EAPAs was the cavernous sinus (34.5%), followed by the sphenoid sinus (31.0%) and the suprasellar region (20.7%). No significant differences in the biochemical test results were found among tumors in different locations. Except for sex, no risk factors related to remission were found. Although no significant differences among different locations were found, the tumors in the cavernous sinus had a relatively higher rate of invisibility in terms of imaging and a higher non-remission rate than tumors in other locations.

CONCLUSIONS

In patients with negative intrasellar findings, the uncommon disease of EAPA should be considered. Due to the endocrine similarity between intrasellar pituitary corticotrophin adenoma and EAPA, the preoperative identification of EAPA depends on a careful review of the imaging examinations. Locations such as the cavernous sinus, sphenoid sinus and suprasellar region should be considered first. Tumor resection is recommended when the diagnosis is confirmed.

Ectopic Cushing's syndrome in a patient with inferior petrosal sinus sampling indicating pituitary-dependent ACTH secretion

In an unclear case of Cushing's syndrome, IPSS identifies the origin of ACTH secretion, and together with MRI enables the localization of an ectopic corticotroph adenoma in the parasellar or cavernous sinuses region.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

Endoscopic Transsphenoidal Surgery for Cushing's Disease: A Review

Ever since the 1960s, transsphenoidal surgery has been the modality of choice for treating Cushing's disease. Subsequent visualization of the pituitary fossa and sphenoid sinus may be done either with the operating microscope or with the relatively new endoscope. The endoscope due to its panoramic view allows greater visualization as compared to the operating microscope. It confers greater access to the cavernous sinus, sella, suprasellar, and parasellar regions and accommodates higher magnifications. It is bi-dimensional, however as opposed to the operating microscope that provides a three-dimensional view and allows greater depth perception. This article provides a comprehensive review of the advantages and disadvantages of the endoscope and compares it to the operating microscope. We hope this article will prove useful to both clinicians and academicians alike in their approach and management of Cushing's disease.

Ectopic Thyroid-Stimulating Hormone-Secreting Pituitary Adenoma of the Nasopharynx Diagnosed by Gallium 68 DOTATATE Positron Emission Tomography/Computed Tomography

BACKGROUND

Ectopic thyroid-secreting hormone (TSH)-secreting pituitary adenomas are rare, with only 9 cases reported in the literature.

CASE DESCRIPTION

We describe a case of an ectopic TSH-secreting pituitary adenoma located in the nasopharynx in a patient initially presenting with signs and symptoms of hyperthyroidism that persisted despite treatment with antithyroid medications. Magnetic resonance imaging of the pituitary gland was normal, although subsequent review by a neuroradiologist revealed a nodule attached to the posterior septum in the nasopharynx that was, in retrospect, seen on several other magnetic resonance imaging scans. Gallium 68 (⁶⁸Ga) DOTATATE positron emission tomography/computed tomography showed increased uptake in the nasopharyngeal nodule. The patient underwent resection of the nasopharyngeal mass with remission of hyperthyroidism. On pathology, the resected mass stained positive for TSH and prolactin.

CONCLUSIONS

This is the first report of use of ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography to aid in localizing an ectopic TSH-secreting tumor. Prior studies have shown that ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography improves detection of small lesions with shorter imaging times and lower radiation doses compared with other modalities. Our case emphasizes the importance of using ⁶⁸Ga-DOTATATE PET/CT in the diagnosis of ectopic pituitary adenomas, as these tumors can be challenging to diagnose radiographically.

Variability in Clinical Presentation and Pathologic Implications of Ectopic Pituitary Tumors: Critical Review of Literature

OBJECTIVE

Pituitary tumors are common, well-described skull base tumors of sellar origin. However, there are reports of rare ectopic pituitary tumors that are found exclusively outside of the sella turcica. Ectopic pituitary tumors have not been holistically analyzed. This study describes presentation and clinical patterns found among patients with ectopic pituitary tumors.

METHODS

A comprehensive review of the literature was performed for clinical descriptions of ectopic pituitary tumors. Reports of 85 applicable cases were evaluated.

RESULTS

The most common locations of ectopic pituitary tumors were the sphenoid sinus, clivus, suprasellar space, nasopharynx, and cavernous sinus. The majority of ectopic pituitary tumors were reported as being functional secretory tumors; they were statistically significantly more likely to be functional tumors than sellar pituitary tumors. Adrenocorticotrophic hormone, prolactin, growth hormone, and thyroid-stimulating hormone-secreting tumors were most commonly found. Bone invasion was reported in more than one third of the cases, and malignant transformations were reported in 6 cases. A large majority of patients presented with hormonal, neurologic, or physiologic symptoms.

CONCLUSIONS

Ectopic pituitary tumors are a rare entity of pituitary tumors with a presentation that can mimic those of other skull base tumors. Clinical presentation often correlates to location of the tumor. Ectopic pituitary tumors were significantly more likely to be functional secretory tumors. They may also exhibit more aggressive behavior than sellar-located tumors. Ectopic pituitary tumors may be part of a spectrum of presenting pathologies. Further genetic or genomic analysis is necessary to better understand their pathogenesis and clinical presentations.

[Ectopia of the pituitary]

The adenohypophysis has a large intrasellar part and two small parts at the pituitary stalk and the pharynx. Near this extrasellar pituitary tissue, and also in sinus sphenoidalis and sinus cavernosus, ectopic pituitary adenomas can develop. They are indistinguishable in structure and function from usual intrasellar adenomas. The neurohypophysis can show dystopias within complex malformations. In so-called pituitary stalk interruption syndrome, a real ectopia of the neurohypophysis is found at the eminentia mediana of the hypothalamus. Ectopic tissue in the pituitary is extremely rare: foci of ganglionic cells were found in the neurohypophysis and adrenocortical tissue in the adenohypophysis. Focal squamous epithelia in the anterior pituitary are a common finding but they are rather metaplastic from parenchymal cells than ectopic tissue. Small foci of ectopic salivary gland tissue are not rare in the intermediate zone.

Root cause analysis of diagnostic and surgical failures in the treatment of suspected Cushing's disease

Cushing's disease (CD) is a condition characterized by excess glucocorticoid from an ACTH pituitary adenoma. Identifying surgical candidates represents a major diagnostic challenge. We performed a root cause analysis (RCA) of treatment failures for patients with suspected CD. The present study aims to categorize failures in treatment. Medical records were reviewed from 2008 to 2017 for all patients treated surgically for suspected CD. Demographics, past medical history, endocrine outcomes, imaging findings, laboratory studies and clinical features were collected. Eighty-five patients were identified with pre-operative suspicion for CD. Thirty-four (40.0%) had undergone prior surgery confirming ACTH adenoma, leaving 51 (60.0%) for analysis. The average length of follow-up was 18.3 ± 24.1 months, 42 (82.4%) patients had postoperative biochemical remission of hypercortisolism. Forty-three (84.3%) had histologically confirmed CD, two (3.9%) were diagnosed with extracranial ACTH-secreting tumors, four (7.8%) had no obvious tumor upon intraoperative exploration, one (1.9%) had suspected pituitary ACTH hyperplasia, and one (1.9%) had no identifiable pathologic tissue despite apparent gross tumor observed during surgery. Thirty-four (66.7%) patients had remission following surgery alone, four (7.8%) after reoperation, and four (7.81%) after radiosurgery. One patient (1.9%) was found to have an ectopic source of ACTH, and one (1.9%) had immunohistochemically confirmed adrenal tumors. On RCA, we identified six categories of treatment failures. CD is a diagnostic challenge that can be difficult to distinguish from other forms of hypercortisolism. Surgical efficacy can be improved with more accurate patient selection, and perhaps with improved imaging methods.

'Ectopic' suprasellar type IIa PRL-secreting pituitary adenoma

BACKGROUND

Ectopic pituitary adenomas (EPAs) are rare, and the suprasellar cistern seems to be the most common location. At this time, no detailed original classification, diagnosis, or treatment protocols for suprasellar pituitary adenomas (SPAs) have been described.

CASE DESCRIPTION

A 19-year-old man showed visual disturbances and lack of libido for 3 years, he suffered a sharp decline in vision with only light perception in the last week. Magnetic resonance imaging scans revealed a large suprasellar cystic lesion with a normal pituitary in the sella turcica. Endocrinological findings showed an extremely high prolactin level of 1250 ng/mL. Because of the sharp decline in vision, the patient underwent total removal of the suprasellar lesion using a transfrontal interhemispheric approach. The tumor pedicle originated in the lower pituitary stalk without any connection to the anterior pituitary gland in the sella turcica, while the diaphragma sellae was incomplete. Clinical and endocrinological cure criteria were fulfilled and postoperative pathology confirmed a prolactin-secreting pituitary adenoma.

CONCLUSION

Ectopic suprasellar pituitary adenomas (ESPAs) are extremely rare intracranial extracerebral tumors. SPAs can be classified into three types according to their origin and their relationship with surrounding tissue. Only type III is theoretically a true ectopic, based on previous reports. Thus, ESPAs are uncommon compared to other EPAs. Our case is the first reported case of a type IIa 'E'SPA and the first description of this subtype classification until now. The pars tuberalis may be different from the pars distalis, and each subtype of adenohypophyseal cells may have different migration characteristics, which leads to different proportions of each hormone-secreting subtype in SPAs and EPAs. Transsphenoidal surgery is minimally invasive, but transcranial surgery may remain a universal option for the treatment of suprasellar lesions.

First Report of Coexistence of Two Ectopic Pituitary Tumors: Rathke Cleft Cyst and Silent Adrenocorticotropic Hormone Adenoma

BACKGROUND

Rathke cleft cysts (RCCs) and pituitary adenomas (PAs) are thought to have a common embryonic ancestry; however, PAs with a concomitant RCC inside the sella turcica are rarely observed. Ectopic pituitary tumors are also rare.

CASE DESCRIPTION

We present the case of a 65-year-old woman with an ectopic RCC in the sphenoid sinus and outside the sella turcica concomitant with an adrenocorticotropic hormone (ACTH)-staining, clinically silent PA. The patient had headache but no endocrine or visual disturbances. Preoperative magnetic resonance imaging revealed infrasellar cystic lesion in the sphenoid sinus with erosion of the clivus and intact sellar floor. The patient underwent gross total microsurgical resection through the transnasal route with an uneventful postoperative course.

CONCLUSIONS

To our knowledge, this is the first reported ectopic RCC located outside the sella turcica with a concomitant ACTH-staining PA. This also appears to be the first ACTH-staining adenoma concomitant with RCC reported in the literature, regardless of location, not presenting with Cushing disease. This case shows that we can now include pituitary adenoma with or without a concomitant RCC in the differential diagnosis of processes in the sphenoid sinus. As both PAs and RCCs are benign sellar lesions, surgical management of a concomitant occurrence of these tumors mainly depends on the size of the lesions and their clinical manifestations. For patients with PA and concomitant RCC, surgical resection should be considered, as there is an approximatrely 20% recurrence rate of the cyst after resection and the possibility of future clival erosion, if left untreated.

Ectopic Adrenocorticotropic Hormone–Secreting Pituitary Adenomas: An Underestimated Entity

BACKGROUND: The diagnosis of Cushing disease is based on endocrinological pa-rameters, with no single test being specific. In some patients, dynamic thin-slice sellar magnetic resonance imaging fails to detect a pituitary tumor.

OBJECTIVE: The purpose of this study is to investigate the role of ectopic pituitary adenoma in this situation.

METHODS: In a retrospective chart review, 5 patients (6%) with ectopic adenomas were identified in 83 consecutive patients undergoing transsphenoidal surgery for adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas by 1 surgeon.

RESULTS: In all 5 patients (all female, 32-41 years of age), an exclusively extrasellar ACTH-secreting adenoma was excised. Three adenomas were located in the cavernous sinus, 1 in the sphenoid sinus, and 1 in the ethmoidal cells. Histologically, none of the tumors showed signs of aggressiveness. Three of the 5 adenomas specifically expressed somatostatin receptor 5. In 4 patients with Cushing disease, postoperative remission was obtained, with 1 recurrence after 14 months. In the patient with Nelson syndrome, ACTH decreased from >800 to <80 pg/mL. Three patients underwent previous surgery elsewhere, including 1 hypophysectomy. In this case, the ectopic adenoma (positive for somatostatin receptor 5) in the ethmoidal cells turned out to be positive on gallium 68 DOTATATE positron emission tomography/computed tomography.

CONCLUSION: The incidence of primarily ectopic ACTH-secreting adenomas in this series was 6%. In cases of negative MRI findings, an ectopic ACTH-secreting adenoma should be taken into account. 68Ga DOTATATE positron emission tomography/computed tomography may identify ectopic pituitary adenomas. Hypophysectomy should always be avoided in primary surgery for CD.

Histological features of pituitary adenomas and sellar region masses

PURPOSE OF REVIEW

Most pituitary region masses are pituitary adenomas; however, when other sellar region masses are encountered by clinicians or pathologists, the differential diagnosis can be broad. This review will focus on updates for pituitary adenomas, as well as briefly discuss some of these other entities: Rathke cleft cyst, hypophysitis, craniopharyngioma, pituicytoma, and spindle cell oncocytoma.

RECENT FINDINGS

The use of new immunohistochemical (IHC) tools for assessing transcription factors, pituitary transcription factor-1, steroidogenic factor-1, and the not-yet-widely available Tpit IHC have provided insights into origin particularly of clinically silent and even hormone-negative pituitary adenomas. IHC for keratins coupled with use of E-cadherin IHC can serve to easily identify sparsely granulated growth hormone adenomas that behave more aggressively and may not respond well to some therapies. Thyroid transcription factor-1 IHC has shown common embryological lineage of pituicytoma, spindle cell oncocytoma, and granular cell tumor of neurohypophysis.

SUMMARY

IHC supplements classification of pituitary adenoma subtypes for clinicians and can confirm diagnosis of nonpituitary adenoma sellar region masses.

Sellar Lesions/Pathology

The sellar region is a tiny anatomic compartment in which many lesions and developmental diseases can be found. If pituitary adenomas represent most of the sellar mass, it is important to recognize other pathologic conditions before any surgical procedure, because the optimal treatment may differ considerably from one lesion to another. A careful clinical evaluation followed by neuroimaging studies and an endocrinologic and ophtalmologic workup will lead, in most cases, to a diagnosis with near certainty. This article provides an overview of sellar diseases with emphasis on their most useful characteristics for clinical practice.

Ectopic Suprasellar Thyrotropin-Secreting Pituitary Adenoma: Case Report and Literature Review

BACKGROUND

Ectopic thyroid-stimulating hormone (TSH)-secreting pituitary adenomas are rare and can often be misdiagnosed as primary hyperthyroidism. We present a case of an ectopic suprasellar TSH-secreting pituitary adenoma. A literature review of previously reported ectopic TSH-secreting and suprasellar pituitary adenomas is included to illustrate the clinical characteristics of this disease entity and the diversity of operative approaches to treating ectopic suprasellar pituitary adenomas.

CASE DESCRIPTION

A 46-year-old man presented with typical clinical signs of hyperthyroidism and a history of progressive visual field impairment and vision loss. Laboratory investigations revealed that the patient had elevated levels of free thyroxine and free triiodothyronine and a normal level of TSH. Neuro-ophthalmologic examination showed right eye/left eye = 1.0/0.6 and left temporal hemianopia. Magnetic resonance imaging revealed a mass located in the suprasellar space. The patient underwent preoperative short-term octreotide treatment followed by gross total resection of the tumor via the extended endoscopic endonasal transtuberculum sellar approach. At 6-month follow-up evaluation, the patient's endocrinologic function tests met the criteria for cure, and magnetic resonance imaging revealed a normal pituitary gland and stalk with no tumor recurrence. Histologic diagnosis confirmed the presence of a TSH-secreting pituitary adenoma.

CONCLUSIONS

To the best of our knowledge, this is the first reported case of an ectopic suprasellar TSH-secreting pituitary adenoma. Preoperative preparation and complete resection are the keys to a cure. The extended endoscopic endonasal transtuberculum sellar approach is an alternative minimally invasive method for the removal of an ectopic suprasellar pituitary adenoma.

Clinical and Anatomic Features of Supraglandular Pituitary Adenomas

OBJECTIVE

Supraglandular pituitary adenoma (SGPA) is one of the extraordinary pituitary adenomas and shows different clinical and radiologic features. We retrospectively reviewed our cases of SGPAs to elucidate the radiologic, anatomic, and clinical features.

METHODS

We identified 9 patients with pathologically proven SGPA and classified them into 2 groups radiologically: either glandular or stalk types. Magnetic resonance images were correlated with intraoperative anatomic differences between the groups. Clinical and endocrinologic characteristics and surgical outcomes were reviewed.

RESULTS

The proportion of SGPAs was 1.2% of all pituitary adenomas surgically treated in our patient cohort. The glandular-type tumors (n = 7) had a thinned or defective diaphragma sellae. There was a clear plane between the tumor and pituitary stalk. For the stalk-type tumors (n = 2), the diaphragma sellae was intact and no clear border between the mass and stalk was found. Endocrinologic and immunohistochemical evaluation showed that 5 of 7 glandular-type tumors (71%) were functioning pituitary adenomas, whereas 2 stalk-type tumors were nonfunctioning. Eight of 9 patients underwent an endoscopic endonasal approach and tumor was totally removed in 7 (78%).

CONCLUSIONS

SGPAs are rare and preoperative diagnosis is possible based on their distinct radiologic, clinical, and anatomic features. SGPAs can be divided into 2 groups according to the anatomic features. The origin of tumor, whether the superior surface of the gland or the pituitary stalk, determined the location, extent, and relationship with the diaphragma sellae. The surgical outcome via an endoscopic endonasal approach was favorable.

Concomitant Cushing's Disease and Marked Hyperprolactinemia: Response to a Dopamine Receptor Agonist

A 38-year-old woman was admitted to our hospital because of amenorrhea, multiple bone fractures, and a Cushingoid appearance. Endocrinological investigations revealed that she had co-existing Cushing's disease and prolactinoma, with a serum level of prolactin (PRL) at 1,480 ng/mL, corticotropin (ACTH) at 81.3 pg/mL, and cortisol at 16.6 μg/dL. Due to the lack of indication for transsphenoidal surgery, cabergoline monotherapy was initiated. A 6-month course of treatment resulted in only subtle amelioration of hypercortisolism, while hyperprolactinemia was dramatically improved. In 5 cases of bihormonal (ACTH/PRL) pituitary macroadenoma reported in the English literature, 2 were initially treated with dopaminergic agonists with substantial effectiveness for both PRL and ACTH. We herein report an extremely rare case of bihormonal macroadenoma in which only PRL was responsive to treatment.