Therapeutic targeting of the pituitary tumor microenvironment

The tumor microenvironment (TME), the complex environment in which tumors develop, has been increasingly targeted for cancer treatment in recent years. Aggressive pituitary tumors and pituitary carcinomas have been so far targeted with immune-checkpoint inhibitors (28 cases, including a large cohort), and anti-angiogenic drugs (34 cases), specifically bevacizumab (30 cases), sunitinib (three cases), and apatinib (one case). Here, we reviewed all these cases, reporting tumor response, potential predictors of response, as well as adverse events. Given that the histological type could potentially influence treatment response, we present the existing data separately for each type. Briefly, under ICIs, complete response was noted in one case, partial response in a third of cases, stable disease in 10% of cases, while 54% of tumors progressed. Under BVZ monotherapy, most cases (57%) showed stable disease, while 36% of tumors progressed; partial response was reported in only one case. The three cases treated with sunitinib monotherapy progressed. Regarding predictive factors of response, the tumor type (aggressive pituitary tumor versus pituitary carcinoma) appears as the strongest predictor of response to ICIs. To date, no predictor of response to anti-angiogenic drugs in the treatment of pituitary carcinomas and aggressive pituitary tumors has been identified. The interest of BZV add-on to first- or second-line chemotherapy warrants further investigation. In addition, we discuss perspectives regarding the TME-targeting in aggressive pituitary tumors and pituitary carcinomas, including perspectives on immunotherapy, anti-angiogenic drugs, as well as on other TME components, namely stromal cells, extracellular matrix, and secreted molecules.

Metastatic pituitary tumors: an institutional case series

PURPOSE

Pituitary carcinomas are a rare entity that respond poorly to multimodal therapy. Patients follow a variable disease course that remains ill-defined.

METHODS

We present an institutional case series of patients treated for pituitary carcinomas over a 30-year period from 1992 to 2022. A systematic review was conducted to identify prior case series of patients with pituitary carcinomas.

RESULTS

Fourteen patients with a mean age at pituitary carcinoma diagnosis of 52.5 years (standard deviation [SD] 19.4) met inclusion criteria. All 14 patients had tumor subtypes confirmed by immunohistochemistry and hormone testing, with the most common being ACTH-producing pituitary adenomas (n = 12). Patients had a median progression-free survival (PFS) of 1.4 years (range 0.7-10.0) and a median overall survival (OS) of 8.4 years (range 2.3-24.0) from pituitary adenoma diagnosis. Median PFS and OS were 0.6 years (range 0.0-2.2) and 1.5 years (range 0.1-9.6) respectively upon development of metastases. Most patients (n = 12) had locally invasive disease to the cavernous sinus, dorsum sellae dura, or sphenoid sinus prior to metastasis. Common sites of metastasis included the central nervous system, liver, lung, and bone. In a pooled analysis including additional cases from the literature, treatment of metastases with chemotherapy or a combination of radiation therapy and chemotherapy significantly prolonged PFS (p = 0.02), while failing to significantly improve OS (p = 0.14).

CONCLUSION

Pituitary carcinomas are highly recurrent, heterogenous tumors with variable responses to treatment. Multidisciplinary management with an experienced neuro-endocrine and neuro-oncology team is needed given the unrelenting nature of this disease.

The treatment of aggressive prolactinomas with everolimus

INTRODUCTION

Aggressive prolactinomas are life-limiting tumors without a standard of care treatment option after the oral alkylator, temozolomide, fails to provide tumor control.

METHODS

We reviewed an institutional database of pituitary tumors for patients with aggressive prolactinomas who progressed following treatment with a dopamine receptor agonist, radiotherapy and temozolomide. Within this cohort, we identified four patients who were treated with everolimus and we report their response to this therapy. Treatment response was determined by a neuroradiologist, who manually performed volumetric assessment and determined treatment response by Response Assessments in Neuro-Oncology (RANO) criteria.

RESULTS

Three of four patients who were treated with everolimus had a biochemical response to therapy and all patients derived a clinically meaningful benefit based upon suppression of tumor growth. While the best overall response as assessed by RANO criteria was stable disease for the four patients, a minor regression in tumor size was appreciated in two of the four patients.

CONCLUSION

Everolimus is an active agent in the treatment of prolactinomas that warrants further investigation.

Medical therapy for refractory pituitary adenomas

INTRODUCTION

Refractory pituitary adenomas are those that have progressed following standard of care treatments. Medical therapy options for these challenging tumors are limited.

PURPOSE

To review the landscape of tumor directed medical therapies and off-label investigational approaches for refractory pituitary adenomas.

METHODS

Literature on medical therapies for refractory adenomas was reviewed.

RESULTS

The established first-line medical therapy for refractory adenomas is temozolomide, which importantly may increase survival, but clinical trial data are still needed to clearly establish its efficacy, identify biomarkers of response, and clarify eligibility and outcome criteria. Other therapies for refractory tumors have only been described in case reports and small case series.

CONCLUSION

There are currently no approved non-endocrine medical therapies for refractory pituitary tumors. There is an urgent need for identifying effective medical therapies and studying them in multi-center clinical trials.

Epidemiology of common and uncommon adult pituitary tumors in the U.S. according to the 2017 World Health Organization classification

PURPOSE

To examine the contemporary epidemiology of adult pituitary tumors with a particular focus on uncommon tumor types, using the 2017 WHO Classification of pituitary tumors.

METHODS

Adult patients presenting with a pituitary or sellar tumor between 2004 and 2017 were identified from the U.S. National Cancer Database, with tumor type categorized according to the 2017 WHO classification. Descriptive epidemiological statistics were evaluated and reported for all pituitary tumor types and subtypes.

RESULTS

113,349 adults with pituitary tumors were identified, 53.0% of whom were female. The majority of pituitary tumors were pituitary adenomas (94.0%), followed by craniopharyngiomas (3.8%). Among pituitary adenomas, whereas 71.6% of microadenomas presented in females, only 46.7% of macroadenomas and 41.3% of giant adenomas did (p < 0.001). For craniopharyngiomas, 71.2% were adamantinomatous and 28.8% were papillary, with adamantinomatous tumors associated with Black non-Hispanic race/ethnicity (OR_adj = 2.44 vs. White non-Hispanic, 99.9 %CI = 1.25-4.75, p < 0.001) in multivariable analysis. The remaining 0.7% (n = 676) of pathology-confirmed pituitary tumor types were composed of: 21% tumors of the posterior pituitary, 16% chordomas, 11% pituitary carcinomas (i.e. adenohypophyseal histology with metastasis; herein most frequently to bone), 10% meningiomas, 8% germ cell tumors, 7% hematolymphoid (largely DLBCLs), and 4% neuronal/paraneuronal (largely gangliogliomas). Pituitary carcinomas and posterior pituitary tumors demonstrated a male predilection (62.2% and 56.0%, respectively), whereas sellar meningiomas predominated in females (84.1%). Age, race/ethnicity, tumor size, and overall survival further varied across uncommon pituitary tumor types.

CONCLUSIONS

Our findings provide a detailed contemporary dissection of the epidemiology of common and uncommon adult pituitary tumors in the context of WHO2017.

Tumor invasion to the spinal region after primary surgery: A case report

Background

It is believed that pituitary carcinoma is a rare disorder and arise from the transformation of benign invasive macroadenomas, and the process of this transformation takes place slowly.

Case Presentation

A 51-year-old man presented with the clinical features of Cushing syndrome and walking impairment who was diagnosed with metastatic corticotroph pituitary carcinoma to the spine region, 6 years after the initial resection of a primary invasive pituitary adenoma. He made a visit to neurosurgery and endocrinology clinic with the chief complaint of weight gain, facial and extremities swelling, paresthesia, weakness, motion and speaking impairments, and HTN which all appeared through the last 1 year; hormonal laboratory tests showed urine free cortisol (UFC) 197.8 and 367. 30 ug/24hrs (36-137), cortisol 8 am after 1 mg overnight dexamethasone test 375 ng/mL (50-250) and ACTH 59 pg/mL. MRI study revealed a mass in the brainstem with the compression effect on spinal region, pituitary imagine does not differ from the last MRI. He underwent a neurosurgery for spinal mass resection, which was successful and the total mass was resected. After surgery, the patient's condition became better.

Conclusion

Pituitary carcinoma is a rare entity impossible to recognize as a primary tumor because its diagnosis by definition requires the presence of metastasis. Clinical awareness of the rare possibility for aggressive adenomas will progress, to metastasize is essential to appropriately monitor patients for possible early detection and treatment of pituitary carcinoma.

Aggressive pituitary neuroendocrine tumors: current practices, controversies, and perspectives, on behalf of the EANS skull base section

Aggressive pituitary neuroendocrine tumors (APT) account for 10% of pituitary tumors. Their management is a rapidly evolving field of clinical research and has led pituitary teams to shift toward a neuro-oncological-like approach. The new terminology "Pituitary neuroendocrine tumors" (PitNet) that was recently proposed to replace "pituitary adenomas" reflects this change of paradigm. In this narrative review, we aim to provide a state of the art of actual knowledge, controversies, and recommendations in the management of APT. We propose an overview of current prognostic markers, including the recent five-tiered clinicopathological classification. We further establish and discuss the following recommendations from a neurosurgical perspective: (i) surgery and multi-staged surgeries (without or with parasellar resection in symptomatic patients) should be discussed at each stage of the disease, because it may potentialize adjuvant medical therapies; (ii) temozolomide is effective in most patients, although 30% of patients are non-responders and the optimal timeline to initiate and interrupt this treatment remains questionable; (iii) some patients with selected clinicopathological profiles may benefit from an earlier local radiotherapy and/or chemotherapy; (iv) novel therapies such as VEGF-targeted therapies and anti-CTLA-4/anti-PD1 immunotherapies are promising and should be discussed as 2nd or 3rd line of treatment. Finally, whether neurosurgeons have to operate on "pituitary adenomas" or "PitNets," their role and expertise remain crucial at each stage of the disease, prompting our community to deal with evolving concepts and therapeutic resources.

Growth hormone secreting pituitary carcinomas: Case report and review of literature

OBJECTIVE

Pituitary carcinoma is a rare tumor, defined as a tumor of adenohypophyseal cells with systemic or craniospinal metastasis. We present a case of a growth hormone (GH)-secreting pituitary carcinoma with a review of literature to better characterize this disease.

DESIGN

Case report and literature review of 25 cases of GH-secreting pituitary carcinomas RESULTS: The age of diagnosis of GH-secreting carcinomas ranged 24-69 years old with a mean age of 44.4 with 52% of cases present in females. Mean latency period between diagnosis of acromegaly and transition to pituitary carcinoma was 11.4 years with mean survival being 3.4 years.

CONCLUSION

Growth hormone (GH)-secreting pituitary carcinomas are rare and hard to distinguish from aggressive pituitary adenomas. From review of literature, treatment options include debulking surgery, radiotherapy, or chemotherapy with dismal outcomes. There are no diagnostic markers or features which can predict metastatic progression of these tumors. Future studies with genomic landscapes and relevant tumor markers are needed to identify pituitary tumors most likely to metastasize.

Non-functional recurrent pituitary adenoma with intracranial metastasis-Pituitary carcinoma: A case report and review of the literature

INTRODUCTION

Pituitary carcinomas are rare, with only a few case reports to date. We present a null cell type non-functioning pituitary carcinoma (NFPC) with intracranial metastases and a review of the literature.

CASE REPORT

A 56-year-old male with a history of an aggressive pituitary adenoma was admitted. Initial MRI highlighted a large intracranial mass with leptomeningeal involvement, simulating meningioma. Based on his previous pathology report of the sellar mass, a diagnosis of null cell type non-functioning pituitary carcinoma has been made.

CONCLUSIONS

An aggressive recurrent pituitary tumor with suprasellar and/or cavernous sinus invasion is the main characteristics of the NFPC. Single or multiple enhancing dural-based mass(es) mimicking meningioma is the most common MRI finding. The proof of malignancy is the same histopathological features of the recurrent aggressive pituitary tumor in the metastases. The histology alone is not distinctive in terms of malignancy. Most patients require a combined surgery, radiotherapy and chemotherapy.

Structure, Function, and Morphology in the Classification of Pituitary Neuroendocrine Tumors: the Importance of Routine Analysis of Pituitary Transcription Factors

The traditional approach to the diagnosis of primary adenohypophyseal cell proliferations uses hormone immunohistochemistry to classify pituitary neuroendocrine tumors (PitNETs). The routine application of immunolocalization of pituitary transcription factors (SF1, PIT1, TPIT, ERα, and recently GATA3) along with adenohypophyseal hormones has taught us critical lessons that are discussed in this communication. We point out that appropriate patient care requires accurate diagnosis and is critical in the era of precision medicine. A misdiagnosis can result in far greater health care costs than the cost of accurate tumor classification and may have other unintended consequences. We provide additional insights about confusing findings in genomic studies, emphasizing that high-quality pathology is essential for strong science and translational research.

Aggressive Pituitary Adenomas and Carcinomas

A subset of pituitary tumors present an aggressive behavior that remains difficult to predict, and in rare cases they metastasize. The current European Society for Endocrinology (ESE) guidelines for the management of aggressive pituitary tumors and carcinomas provide valuable guidance, but several issues remain unaddressed because of the scarcity of data in the literature. This article presents key clinical aspects regarding aggressive pituitary tumors and carcinomas, and also discusses some of the unanswered questions of the ESE guidelines, focusing on both diagnosis and treatment.

Long-course temozolomide in aggressive pituitary adenoma: real-life experience in two tertiary care centers and review of the literature

PURPOSE

Aggressive pituitary adenomas (APAs) and pituitary carcinomas (PCs) are challenging for their invasive nature, resistance to treatment and recurrences. Temozolomide (TMZ) is used with benefit and well-tolerated toxicity profile in APAs and PCs. In most studies patients received ≤ 12 cycles but the best length of treatment is debated since other options after discontinuation are scarce and a second course is mainly unsuccessful.

METHODS

We report outcomes of 8 patients with APAs and PCs treated with TMZ for more than 12 continuous cycles with a literature review. Data were retrospectively collected from Padua and Milan University Hospitals. TMZ was used as a single agent (150-200 p.o. mg/m2 daily, 5/28 days) for 14 to 45 cycles.

RESULTS

Eight patients (7 M), 7 APAs and 1 PC. Previous treatments included neurosurgery and radiotherapy in all cases except two giant masses (ACTH-silent APA and prolactinoma). No patient had progression disease (PD) during long-term treatment nor toxicities. No one had complete response (CR) but four had partial response (PR). Four ACTH+ tumors maintained stable disease (SD) but the secretion pattern improved in all. After drug withdrawal, three had delayed PD (2 after 18 and one after 29 months, all ACTH+); two are still in SD.

CONCLUSIONS

TMZ may be useful and well-tolerated in APAs and PCs as a long-term therapy. PR appears within the first cycles with no escape throughout the treatment; most patients achieve SD. We suggest extended protocols particularly in responsive ACTH+  PAs and PCs, when further therapies may be unsuccessful.

Malignancy course of pituitary adenoma in MEN1 syndrome: Clinical-Neuroradiological signs

Pituitary carcinomas (PCa) are extremely rare, indistinguishable from pituitary adenomas on histopathological grounds and have a poor prognosis. Most PCa start as PRL or ACTH secreting tumors in males, with relapsing invasive behaviour, refractoriness to medical and radiotherapy and increasing hormonal levels. The presence of distant metastases is still required for the diagnosis of PCa. The association with genetic endocrine diseases must be taken into account, since it adds further risk of evolution towards malignancy. Intradural spinal metastases have also been reported, so a complete craniospinal MR evaluation is recommended, when clinically indicated. We report a case of PCa, associated with MEN1 syndrome, with evidence of meningeal spread to the tentorium cerebelli, clival dura and spinal drop metastases mimicking spinal nerves schwannomas.

Liver metastases from pituitary carcinomas mimicking visceral well-differentiated neuroendocrine tumors: a series of four cases

Background

Pathologists frequently encounter neuroendocrine tumors (NETs) presenting as multiple liver masses in routine practice. Most often, these are well-differentiated tumors with characteristic histologic features. In contrast, pituitary carcinoma is very rare, and there is limited data on its natural history and pathologic characterization.

Methods

The aim of this study was to describe clinical characteristics, histomorphology, immunophenotype and follow-up of pituitary carcinoma involving the liver and mimicking well-differentiated NETs of visceral origin. We selected a group of well-differentiated NETs of the pancreas to use as immunophenotypic controls. We identified 4 patients (age range, 51 to 73) with pituitary corticotroph carcinoma with liver metastases. Three patients presented with Cushing syndrome.

Results

All cases histologically resembled well-differentiated NETs of visceral origin with Ki-67 proliferation indices of 5–42% and expression of T-PIT; metastatic tumors were not immunoreactive with CDX2, Islet 1 or TTF-1.

Conclusions

Frequently, these cases display adrenocorticotropic hormone (ACTH) secretion and pituitary-specific transcription factor immunohistochemistry may be used as a reliable marker to distinguish metastatic pituitary carcinoma from NETs of visceral origin in addition to delineating a corticotroph carcinoma from somatotroph, lactotroph, thyrotroph, and gonadotroph lineage. Although rare, the differential diagnosis of pituitary carcinoma should be considered in metastatic well-differentiated NETs in which the site of origin is uncertain. In summary, pituitary corticotroph carcinoma can metastasize to the liver and mimic well-differentiated NET.

Definition and diagnosis of aggressive pituitary tumors

Pituitary adenomas are considered benign tumors, but approximately 10% of them can have an aggressive behavior and more rarely (0.2%) can present metastasis, being classified as pituitary carcinomas. Aggressive adenomas are generally large and invasive tumors that present unusually rapid growth and/or that grow irrespective of conventional treatment with surgery, medical therapy and radiotherapy. Nevertheless, large tumors, as well as invasive tumors are not always aggressive, with this definition being possible only after clinical follow-up of these tumors, with growth rate and response to therapies being key points to its diagnosis. The correct identification and diagnosis of aggressive adenomas is of great importance as they are associated with great morbidity and increased mortality.

Temozolomide therapy for aggressive pituitary tumours - current understanding and future perspectives

The use of temozolomide (TMZ) for the management of aggressive pituitary tumours (APT) has revolutionised clinical practice in this field with significantly improved clinical outcomes and long-term survival. Its use is now well established however a large number of patients do not respond to treatment and recurrence after cessation of TMZ is common. A number of challenges remain for clinicians such as appropriate patient selection, treatment duration and the role of combination therapy. This review will examine the use of TMZ to treat APT including mechanism of action, treatment regimen and duration; biomarkers predicting response to treatment and patient selection; and current evidence for administration of TMZ in combination with other agents.

Are aggressive pituitary tumors and carcinomas two sides of the same coin? Pathologists reply to clinician's questions

Pituitary adenohypophyseal tumors are considered as benign and termed "adenomas". However, many tumors are invasive and a proportion of these exhibit an "aggressive behavior" with premature death due to progressive growth. Only very rare (0.2%) tumors with metastases are considered malignant and termed "carcinomas". Taking into account this variability in behavior and the oncological definition, pathologists have proposed changing the term adenoma to tumor. Here we explain why use the term tumor instead of adenoma and identify tumor characteristics, associated with a high risk for poor prognosis. In a cohort of 125 tumors with aggressive behavior (APT) and 40 carcinomas with metastases (PC), clinical and pathological features were very similar. The comparison of this cohort (APT+PC) with a reference surgical cohort of 374 unselected patients clearly shows that the two cohorts differ greatly, especially the percentage of tumors with Ki67 ≥ 10% (35%vs3%; p < 0.001). A five-tiered prognostic classification, associating invasion and proliferation, identified grade 2b tumors (invasive and proliferative), with a high risk of recurrence/progression. Because half of the APT+ PC tumors have a Ki67 index ≥10%, and 80% of them show 2 or 3 positive markers of proliferation, we suggest that tumors that are clinically aggressive, invasive and highly proliferative with a Ki67 ≥ 10%, represent tumors with malignant potential. The percentage of grade 2b tumors, suspected of malignancy, which will become aggressive tumors or carcinomas is unknown. It is probably very low, but higher than 0.2% in surgical series. Early identification and active treatment of these aggressive tumors is needed to decrease morbidity and prolong survival.

Pituitary carcinoma: Two case reports and review of literature

BACKGROUND

Pituitary carcinoma is a rare type of malignancy that can be very difficult to diagnose and treat. Many cases were diagnosed at autopsy. Delays in diagnosis often adversely impact patients' outcomes. Even with prompt diagnosis, treatment decisions remain challenging in the absence of randomized controlled trials.

CASE SUMMARY

We report two cases of pituitary carcinoma in men with a history of pituitary adenoma. In the first case, a 55-year-old man was initially diagnosed with pituitary macroadenoma. He underwent subtotal debulking of the tumor followed by adjuvant radiotherapy. Subsequently, he developed relapsed disease and multifocal intracranial metastases and a diagnosis of pituitary carcinoma was rendered. He passed away despite several lines of systemic therapies including temozolomide, lomustine and bevacizumab. Another 52-year-old man was diagnosed with atypical pituitary adenoma with presentation of sudden onset of vision loss in the right eye. He had recurrent pituitary carcinoma with spinal metastases, treated with surgery, radiation and temozolomide.

CONCLUSION

Pituitary carcinoma is a rare neoplasm with poor prognosis that is difficult to diagnose and treat. The small number of cases restricts our ability to design randomized clinical trials. Management is largely driven by retrospective studies and case series. Establishing molecular biomarkers and comprehensive genomic profiling could help in decisions about diagnosis and management of pituitary carcinoma.

Aggressive prolactinomas: how to manage?

PURPOSE

Aggressive prolactinomas are defined as radiologically invasive tumors which cannot be cured by surgery, and that have an unusually rapid rate of tumor growth despite dopamine agonist treatment and surgery. In some cases, metastasis occurs, defining prolactin carcinoma which is the second most frequent pituitary carcinoma.

METHODS

A literature search was performed to review the available data on the treatment of aggressive pituitary prolactinomas or carcinomas.

RESULTS

When optimal standard therapies (high dose cabergoline, surgery and radiotherapy) failed, temozolomide, an alkylating drug, is currently the best option, allowing to control tumor growth in about 50% of treated prolactinomas and improving overall survival of these patients. However, long-term complete response occurs in a limited subgroup of tumors. Alternative drugs could be discussed in a subset of aggressive prolactinomas either before temozolomide (pasireotide, peptide receptor radionuclide therapy…) or after temozolomide failure.

CONCLUSION

Despite the significant improvement obtained with the use of temozolomide, a need for alternative drugs persists since a majority of these tumors are resistant or will recur during the follow-up. Patients suffering from such a rare condition should have access to clinical trials available for other types of rare cancers, such as tyrosine kinase inhibitors or immunotherapy.

Pituitary carcinomas: Rare and challenging

BACKGROUND

Pituitary carcinomas (PCs) are defined as adenohypophyseal tumors with metastatic activity within and outside the boundaries of the central nervous system (CNS). The condition is rare and therefore seldom reported; most lesions are hormone producing and have a tendency for complex evolution. As such, the management of PCs remains difficult. We present an illustrative case of PC with a brief review of the recent medical literature.

CASE DESCRIPTION

A 58-year-old patient was diagnosed with prolactinoma in 2005. The ensuing biochemical and radiological evolution proved contentious; local tumor control was never fully achieved despite multimodal management including pharmacological treatment, repeated resections, and radiotherapy. In late 2017, the patient developed metastatic lesions within the confinements of the CNS requiring further surgical interventions, high-dose radiation, and systemic treatment.

CONCLUSION

As it was the case in our patient, PCs require tailored, multimodal treatments according to the degree of infiltration, site of invasion, and hormone status. Further studies are necessary to understand the mechanisms promoting "extra-sellar" activity, particularly at distant sites; the identification of biomarkers exposing the risk of PC remains a crucial aspect of diagnostics, prevention and future customized therapies.

Lower all-cause mortality rates in patients harboring pituitary carcinoma following the introduction of temozolomide

OBJECTIVE

To evaluate the impact of temozolomide (TMZ) introduction on the survival of patients with pituitary carcinoma (PC) compared to aggressive pituitary adenoma (APA).

METHODS

Retrospective analysis of the Surveillance Epidemiology and End-Results database (SEER), including patients diagnosed with PC or APA between 1973 and 2015. Age-adjusted Kaplan-Meier analyses were performed, comparing all-cause mortality (ACM) rates before the year 2006, the time of TMZ introduction ("period 1"), and afterwards ("period 2"), in patients harboring PC and APA.

RESULTS

Among 107 patients, 18 (16.8%) harbored PC. The prevalence of PC and APA was comparable between genders, ethnicities and age strata. Patients harboring any pituitary tumor (PC or APA) had comparable risk for ACM and disease-specific mortality between the two time periods. However, among patients harboring PC, the risk for ACM was significantly lower in period 2 vs. period 1 (p = 0.021), becoming comparable to the risk of ACM in patients diagnosed with APA (p = 0.48).

CONCLUSIONS

In this large cancer-database-based analysis we observed improved overall survival in patients harboring PC in the years following the introduction of TMZ.

Unusual Course of an Aggressive Pituitary Prolactinoma: Case Report and Review of the Literature

Pituitary carcinomas are rare tumors with heterogeneous behaviors. Their carcinogenesis is still unknown. Consequently, treatment is multimodal and not standardized. Dopamine (DA) agonists are used as first-line treatments, while radiotherapy and surgery may be used for local control of invasive tumors. We describe the case of a 35-year-old male who presented with an invasive prolactinoma, managed initially with a transsphenoidal resection, postsurgical radiotherapy and DA agonists. The patient posteriorly presented a sole metastatic lesion to the lumbar spine that was later managed with local radiotherapy. Due to pituitary recurrence of the lesion, multiple surgical resections were needed until further treatment was declined. The clinical course in this patient was unusual. He lived for 13 years after initial diagnosis, with a very invasive tumor without systemic chemotherapy. Radiotherapy is used in pituitary tumors in which surgery fails; we hypothesize that it contributed to the malignant transformation and the late resistance to DA agonists in our patient. Several biomarkers in tumoral tissue have been evaluated regarding their association with malignancy and aggressive behaviors, although more studies are still needed. Therapeutic strategies are limited, without evidence on the impact on overall survival and prognosis. Risk factors associated with early malignancy in pituitary prolactinomas include recurrent behavior, increase in prolactin levels with a stable sellar mass, and secondary development of DA agonist resistance. However, there are still no conclusive answers as to whether physicians should rigorously follow up these patients or provide direct therapy with aggressive approaches.

An Institutional Experience of Tumor Progression to Pituitary Carcinoma in a 15-Year Cohort of 1055 Consecutive Pituitary Neuroendocrine Tumors

Pituitary carcinoma is a rare disease, defined by the presence of cerebrospinal or distant metastasis of a pituitary neuroendocrine tumor (PitNET). To review our institutional experience of pituitary carcinoma, we searched the database of the UHN Endocrine Oncology Site group and the University Health Network pathology laboratory information system from 2001 to 2016. Among 1055 PitNETs from 1169 transsphenoidal resections, we identified 4 cases of pituitary carcinoma, indicating that pituitary carcinoma represents around 0.4% of PitNETs. All four patients were women. The age at initial presentation ranged from 23 to 54 years. Two patients had Cushing disease with corticotroph tumors; one was initially a densely granulated corticotroph tumor that evolved to become sparsely granulated, while the other was a Crooke cell tumor. One patient had a functioning sparsely granulated lactotroph tumor and one had a clinically silent poorly differentiated PIT1 lineage tumor. Apart from a relatively high Ki67 labeling index (≥ 10%) in three tumors, there were no cytomorphologic features at the time of initial presentation that could predict subsequent metastatic behavior. The time from diagnosis of the pituitary neuroendocrine tumor to the diagnosis of malignancy was 3 to 14 years. Therapies included somatostatin analogs, external beam radiotherapy, chemotherapies including capecitabine/temozolomide, everolimus, sunitinib, bevacizumab, and peptide receptor radionuclide therapy (PRRT). One patient died of disease 18 years after initial diagnosis, underscoring the protracted course of this ultimately fatal neuroendocrine malignancy.

Corticotrophic pituitary carcinoma with cervical metastases: case series and literature review

PURPOSE

Pituitary tumors are the second most common intracranial tumors, however, pituitary carcinoma is a rare clinical entity which represents only 0.1-0.2% of all pituitary tumors. Diagnosis of pituitary carcinoma requires the presence of metastasis. Early identification of pituitary carcinoma is difficult, and only recently have guidelines been published for the treatment of aggressive pituitary tumors. We present two cases from our institution, with a review of other cases available in literature in order to better characterize this rare disease.

METHODS

A retrospective review of two patients with pituitary carcinoma treated at a tertiary medical center was performed. The MEDLINE database was searched for all cases of pituitary carcinoma. Information for age at diagnosis, sex, pituitary tumor type, latency period from pituitary tumor to presentation of carcinoma, sites of metastasis, number of surgical therapies, radiation and chemotherapy, and survival after diagnosis were collected.

RESULTS

A total of 69 studies were available for review for a total of 72 unique cases. The average age at diagnosis was 46.3 years. The most common tumors were ACTH-secreting (34.7%), Prolactin-secreting (23.6%), and Null Cell (15.3%). The average latency period from pituitary tumor diagnosis to metastasis was 9 years. All patients underwent surgical therapy during their treatment, with an average of 2.76 procedures. The mortality rate was 54.8% with average time to death after diagnosis of approximately 10 months.

CONCLUSIONS

Pituitary carcinoma is a rare disease with high mortality rate and is a diagnostic and treatment challenge. Further study is required but is difficult due to its low incidence.

Pituitary Carcinoma in a Patient with an SDHB Mutation

We present the first case of pituitary carcinoma occurring in a patient with a succinate dehydrogenase subunit B (SDHB) mutation and history of paraganglioma. She was initially treated for a glomus tumour with external beam radiotherapy. Twenty-five years later, she was diagnosed with a non-functioning pituitary adenoma, having developed bitemporal hemianopia. Recurrence of the pituitary lesion (Ki-67 10% and p53 overexpressed) occurred 5 years after her transsphenoidal surgery, for which she underwent two further operations followed by radiotherapy. Histology showed large cells with vacuolated clear cytoplasm with positive immunostaining for steroidogenic factor 1 (SF1) and negative staining for pituitary hormones. Four years after the pituitary radiotherapy, two metastatic deposits were identified: a foramen magnum lesion and an intradural extra-medullary cervical lesion at the level of C3/C4. There was also significant growth of the primary pituitary lesion with associated visual deterioration. A biopsy of the foramen magnum lesion, demonstrating cells with vacuolated, clear cytoplasm and positive SF1 staining confirmed a pituitary carcinoma, for which she was commenced on temozolomide chemotherapy. There was dramatic clinical improvement after three cycles and reduction in the size of the lesions was observed following six cycles of temozolomide, and further shrinkage after 10 cycles. The plan is for a total of 12 cycles of temozolomide chemotherapy. SDH mutation-related pituitary tumours have an aggressive phenotype which, in this case, led to metastatic disease. SF1 immunostaining was helpful to identify the tissue origin of the metastatic deposit and to confirm the pituitary carcinoma.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Case report: ACTH-secreting pituitary carcinoma metastatic to the liver in a patient with a history of atypical pituitary adenoma and Cushing's disease

Background

Pituitary carcinoma is a rare entity requiring the presence of metastasis to confirm its malignant potential. We report a case of pituitary carcinoma and discuss the diagnosis and management of this lesion in relation to the existing literature.

Case presentation

The patient is a 51-year-old woman with Cushing’s disease and intact adrenal glands who was diagnosed with metastatic pituitary carcinoma to the liver, 29 months after initial resection of an ACTH-secreting primary atypical pituitary adenoma (APA). Prior to detection of this metastasis the patient underwent repeat resection and radiotherapy for residual cavernous sinus disease. The metastatic lesion was detected by interval surveillance of serum ACTH and 24-hour urine cortisol, which despite stable pituitary MRI, were significantly elevated. These abnormalities prompted a PET scan that demonstrated hypermetabolic liver parenchyma, which was suspicious for metastasis on abdominal MRI. An ultrasound-guided liver biopsy demonstrated nests of moderately-differentiated cells with intermediate-sized, monotonous nuclei, distinct nucleoli, and abundant basophilic cytoplasm, confirmed by immunohistochemistry to represent metastatic pituitary carcinoma. The liver lesion was subsequently successfully removed by wedge resection. One year later, the patient’s residual cavernous sinus disease grew markedly, and she was placed on dual-agent chemotherapy consisting of oral temozolomide and capecitabine, with stabilization of her intracranial disease to present, although liver metastases recurred.

Conclusions

Pituitary carcinoma is a rare entity impossible to recognize as a primary tumor because its diagnosis by definition requires the presence of metastasis. Maintaining awareness of the entity and its precursor lesion APA is essential for its accurate pathologic diagnosis and appropriate management.

Metastatic Pituitary Carcinoma to Cervical Lymph Node: Diagnosis by Fine Needle Aspiration and Review of the Literature

BACKGROUND

Pituitary carcinomas are rare neoplasms whose designation requires demonstration of metastatic disease. No specific morphologic features can reliably distinguish pituitary carcinomas from pituitary adenomas, rendering the diagnosis particularly challenging. Furthermore, as reports of pituitary carcinoma on fine needle aspiration (FNA) biopsy are exceedingly rare in the literature, the cytological features of pituitary carcinoma are poorly characterized.

CASE REPORT

Here we describe a case of pituitary carcinoma in a 67-year-old woman with history of recurrent adrenocorticotropic hormone (ACTH)-producing pituitary adenoma who presented with a persistent left cervical nodule for 2 years. Ultrasound-guided FNA of the nodule consisted of loosely cohesive clusters of epithelioid cells with marked cytologic atypia, intermediate to large nuclei, relatively irregular nuclear contour, coarse granular chromatin, prominent nucleoli, and delicate finely granular cytoplasm. Immunohistochemical stains performed on the cell block revealed positivity for synaptophysin, chromogranin and ACTH with an increased Ki-67 proliferation index (approximately 25%). Review of the patient's previously resected pituitary tumor showed similar cytomorphologic features.

CONCLUSION

Given the similar cytologic features of pituitary carcinomas compared to other neuroendocrine tumors, it is important to obtain a complete clinical history and maintain a high index of suspicion in order to make a correct diagnosis of pituitary carcinoma on FNA.

Successful treatment of pituitary carcinoma with concurrent radiation, temozolomide, and bevacizumab after resection. J Clin Neurosci. 2017;41:75-77. [PMID: 28291643 DOI: 10.1016/j.jocn.2017.02.052]

The optimal treatment of pituitary carcinomas (PC) is unknown. Treatment includes surgical resection, radiation, and more recently, temozolomide (TMZ). Pituitary adenomas have relatively high expression of vascular endothelial growth factor; therefore, bevacizumab, an antiangiogenic agent, has been used in a small number of aggressive or malignant pituitary tumors after recurrence. However, it has not been administered concurrently with other chemotherapeutic agents or combined with radiation therapy in PC. We present a 63-year-old man with an adrenocorticotropic hormone (ACTH)-secreting PC, causing visual loss. It was resected transsphenoidally. There were several notable factors placing the patient at high risk for recurrence including distant metastasis in the form of a pulmonary nodule. Morphologically, his tumor was a pituitary neoplasm with malignant histopathologic features. It had abundant mitotic figures and zones of necrosis. Six weeks post-surgery, the patient started concurrent chemoradiation, using combination therapy with TMZ and bevacizumab. TMZ was continued for 12 cycles in the adjuvant setting. The ACTH was effective as a serum-based tumor marker and normalized during treatment. The patient is alive, five years after diagnosis, with no recurrence to date. This is the first case of pituitary carcinoma treated successfully with concurrent chemoradiation therapy that combined TMZ and bevacizumab with a long-term follow up.

Novel aspects in histopathology of the pituitary gland

The sellar and parasellar region is a complex anatomical area in which several diseases may develop. The pituitary gland may be affected by a wide range of conditions having similar clinical characteristics. Diagnosis of these lesions requires a multidisciplinary approach including, in addition to clinical, laboratory, imaging, and surgical findings, histological diagnosis of pituitary adenomas to guide therapeutic management. As the result of development in recent years of new immunohistochemical techniques, histopathological classification has become more complex and wide, and not only continues to be the gold standard in diagnosis, but also has prognostic implications. The aim of this review is to provide a clear and simple update of the main concepts of histological diagnosis of the most common pituitary conditions, especially for professionals in direct contact with such diseases.

Paradoxical and atypical responses to pasireotide in aggressive ACTH-secreting pituitary tumors

PURPOSE

Pasireotide is the only pituitary targeted medication registered for the treatment of Cushing's disease. Drug efficacy data are largely based on a major prospective study in which the vast majority of patients had microadenomas. The purpose of this study was to summarize results of pasireotide treatment of ACTH secreting macroadenomas from our center.

METHODS

Retrospective review of data extracted from clinical files.

RESULTS

Three patients presented with large and invasive macroadenomas that required several surgical interventions and radiotherapy treatments. Patient 1 is a 57 year-old male who developed an extreme (27-fold) paradoxical response of urinary free cortisol (UFC) levels as measured 2 weeks after pasireotide institution, which increased further (71-fold) in response to dose increment but decreased to baseline levels after treatment interruption. Patient 2 is a 44 year old woman with a long standing (26 years) ACTH-secreting carcinoma metastatic to bone and after bilateral adrenalectomy. After an initial excellent response to pasireotide treatment, ACTH levels escaped suppression and a further rebound was noted 6 weeks after treatment interruption. Patient 3 is a 53 year old man that after escape from temozolomide therapy was started on pasireotide and rapidly responded by almost normalizing UFC excretion after 4 weeks, but returned to baseline UFC levels after four additional weeks of treatment.

CONCLUSIONS

We describe as yet unreported atypical responses to pasireotide treatment in patients with aggressive ACTH-secreting tumors. Increased vigilance is recommended during pasireotide treatment of such patients.

Radiotherapy with concurrent temozolomide for the management of extraneural metastases in pituitary carcinoma

BACKGROUND

Pituitary carcinomas (PC) are uncommon neuroendocrine tumors, accounting for 0.1 % of all pituitary tumors. The diagnosis of PC is based on the presence of metastases from a pituitary adenoma, and not by local invasion or pathological features alone. PC is typically resistant to therapy, with a median overall survival of only 31 months. There is no standard treatment for PC, but maximal safe resection and radiation are performed when possible. Encouraging preliminary data on the use of temozolomide (TMZ)-based therapy has been previously reported.

METHODS

We report the response to therapy and safety of radiation with concurrent temozolomide (RT/TMZ) in 2 adult patients with heavily pretreated PC and extraneural metastases.

RESULTS

Both patients had prior history of pituitary macroadenoma. At the time of diagnosis of PC, Ki-67 % was 24.2 and 10 %, with positive p53 staining in one case. Metastatic sites included lymph nodes, liver and bone. Case-1 received RT/TMZ to the tumor bed in the skull base and to the metastases in the cervical lymph nodes. Case-2 received RT/TMZ to recurrent tumor involving portacaval lymph nodes. Both patients achieved excellent long-term control of the sites of treated extraneural metastases, with no significant acute or delayed toxicity.

CONCLUSIONS

RT/TMZ was safely delivered and might provide sustained control of extraneural metastases in PC. Although this retrospective report has limitations, RT/TMZ can be considered as a therapeutic option for the management of extraneural metastases in PC.

Secreting Follicle-Stimulating Hormone Pituitary Carcinoma with Cervical Metastasis

BACKGROUND

Pituitary carcinoma is defined by either metastases outside the central nervous system or noncontiguous foci within the central nervous system. This case report details the first documented case of a pathologically isolated follicle-stimulating hormone-secreting pituitary carcinoma and its presentation of metastasis.

CASE DESCRIPTION

A 63-year-old man developed intrascapular pain radiating up his neck to his occiput. He had undergone a transsphenoidal hypophysectomy 2 years previously for an atypical pituitary macroadenoma. Subsequent magnetic resonance imaging identified a focal, solitary, well-circumscribed, homogeneous T2 high-signal intradural, extramedullary enhancing mass at C2-3 in a right ventral parasagittal location, extending toward the exit foramina. On surgical excision with a laminectomy, the mass demonstrated a morphologic appearance of a malignant neuroendocrine tumor with an immunoprofile similar to the original atypical pituitary adenoma. This was in keeping with metastatic disease secondary to a follicle-stimulating hormone-secreting pituitary carcinoma.

CONCLUSIONS

Although rare, metastatic spread is recognized in patients with atypical pituitary adenoma. This should form the differential diagnosis for such patients presenting with symptoms that could be attributed to metastatic lesions within the neuraxis. In these patients, who undergo regular surveillance in joint neuroendocrine clinics, more urgent investigation of new spinal pain should be instigated to exclude metastatic disease.

Prolactin-Secreting Pituitary Carcinoma with Dural Metastasis: Diagnosis, Treatment, and Future Directions

BACKGROUND

Pituitary carcinoma is extremely rare, representing approximately 0.2% of all surgically resected pituitary neoplasms. It is thought to arise from World Health Organization grade II (atypical) pituitary adenomas. Pituitary carcinoma is defined by metastasis; it is otherwise indistinguishable from atypical pituitary adenomas, which can be considered carcinoma in situ. Pituitary carcinoma is difficult to diagnose and treat and is associated with poor long-term outcomes.

CASE DESCRIPTION

A 75-year-old man presented with a highly aggressive and treatment-refractory atypical prolactinoma that transformed into a prolactin carcinoma. Although the patient experienced early hormonal and surgical remission and local tumor control after tumor resection and fractionated radiation, isolated dural-based metastases were subsequently noted following gradual elevation in serum prolactin despite ongoing dopamine agonist therapy. En bloc resection was performed of the pathology-confirmed, prolactin-staining dural metastases. At 1-year follow-up, there was no further evidence of metastatic disease, and normalization of serum prolactin was observed.

CONCLUSIONS

Long-term surveillance using serum prolactin as a tumor biomarker and correlation to imaging studies were critical for the diagnosis and interval screening for recurrence. This technique can be applied to all secretory atypical pituitary adenomas to improve early detection of potential metastasis. Further research, especially of genetic and epigenetic characteristics, could readily improve the diagnosis and treatment of pituitary carcinomas.

Pituitary carcinoma with intraspinal metastasis: report of two cases and review of the literature

Pituitary carcinomas are rare malignant neoplasms with diagnostic and management challenges. Patients with pituitary carcinomas have extremely poor outcomes. In this report, the authors describe two cases of pituitary carcinomas with intraspinal metastasis (Case 1: 42-year-old man with a history of pituitary adenoma 16 years ago developed an intraspinal lesion at C4-C5; Case 2: 26-year-old women with a history of growth hormone-producing pituitary adenoma 9 years ago developed intraspinal lesion in the sacral canal). Both patients underwent spine surgery. The intraspinal lesions were confirmed as metastatic pituitary carcinomas based on the histomorphology and immunohistochemical stains. The authors reviewed the literature for the diagnosis, treatment, and prognosis of intraspinal metastasis from pituitary carcinomas.

The role of temozolomide in the treatment of aggressive pituitary tumors

Pituitary tumors are amongst the most common intracranial neoplasms and are generally benign. However, some pituitary tumors exhibit clinically aggressive behavior that is characterized by tumor recurrence and continued progression despite repeated treatments with conventional surgical, radiation and medical therapies. More recently, temozolomide, a second generation oral alkylating agent, has shown therapeutic promise for aggressive pituitary adenomas and carcinomas with favorable clinical and radiographic responses. Temozolomide causes DNA damage by methylation of the O(6) position of guanine, which results in potent cytotoxic DNA adducts and consequently, tumor cell apoptosis. The degree of MGMT expression appears to be inversely related to therapeutic responsiveness to temozolomide with a significant number of temozolomide-sensitive pituitary tumors exhibiting low MGMT expression. The presence of high MGMT expression appears to mitigate the effectiveness of temozolomide and this has been used as a marker in several studies to predict the efficacy of temozolomide. Recent evidence also suggests that mutations in mismatch repair proteins such as MSH6 could render pituitary tumors resistant to temozolomide. In this article, the authors review the development of temozolomide, its biochemistry and interaction with O(6)-methylguanine-DNA methyltransferase (MGMT), its role in adjuvant treatment of aggressive pituitary neoplasms, and future works that could influence the efficacy of temozolomide therapy.

Invasive, atypical and aggressive pituitary adenomas and carcinomas

Aggressive pituitary adenomas have a high risk of recurrence, a lack of therapeutic response, and resistance to conventional treatment. So far, no satisfactory biomarkers are available for predicting their behavior. Some specific pituitary adenoma histotypes are more prone to follow an aggressive behavior. Pituitary carcinomas are rare and show cerebrospinal and/or systemic metastasis. They have worse prognosis than aggressive adenomas, and radiation is of limited use in their treatment.

Drop metastasis of adrenocorticotropic hormone-producing pituitary carcinoma to the cauda equina

The diagnosis of pituitary carcinoma cannot be made easily histologically, and most cases of pituitary carcinoma are diagnosed only after the clinical detection of metastasis. Distant metastasis of pituitary tumor occurs in 0.1% to 0.2% of cases and has been reported in the liver, bone and central nervous system, with only one case of metastasis to the cauda equine reported. This study describes a rare case of the drop metastasis of adrenocorticotropic hormone-producing pituitary adenocarcinoma to the cauda equina, causing cauda equina syndrome.