Association of Pathology Markers with Somatostatin Analogue Responsiveness in Acromegaly.

Background: Somatotroph adenomas (SAs) exhibit a variable responsiveness to somatostatin analogue (SS-a) treatment, a process that is not well understood. We investigated established and novel histological markers as predictors of SS-a responsiveness. Methods: We retrospectively investigated pathology samples from 36 acromegalic patients that underwent transsphenoidal surgery. Clinical, hormonal, and imaging data were available in 24/36 patients, before and after SS-a treatment. Specimens were semiquantitatively analyzed with immunocytochemistry for Ki-67, KER, SSTR-2, SSTR-5, ZAC-1, E-cadherin, and AIP. Results: Collectively, 18 (50%) adenomas were each classified as densely/sparsely granulated somatotroph adenomas (DGSAs/SGSAs), respectively. Patients that received preoperative SS-a had lower expression of SSTR-2 compared to those that did not (2.0 (1.0, 3.0) vs. 3.0 (3.0, 3.0), p = 0.042). Compared with DGSAs, SGSAs had higher Ki-67 labeling index (LI) (1.0 (0.5, 1.0) vs. 2.0 (1.0, 3.5), p = 0.013), and a higher proportion of high MR T2 signal (1 (6%) vs. 6 (33%), p = 0.035), and tended to express less ZAC-1 (p = 0.061) and E-cadherin (p = 0.067). In linear regression corrected for baseline growth hormone (GH), ZAC-1 immunostaining was significantly associated with a decrease in GH levels after SS-a treatment (beta (95% confidence interval): -1.53 (-2.80, -0.26), p = 0.021). No markers were associated with changes in circulating insulin-like growth factor-I (IGF-I) after treatment with SS-a. Conclusion: The novel marker ZAC-1 was associated with GH response to medical treatment with SS-a. The SGSA cases were characterized by higher Ki-67 values and MR T2 signals indicative of an inferior response to SS-a. These findings improve our understanding of the mechanisms underlying SA response to medical treatment.

Thyroid Paraganglioma With Medullary Carcinoma: A Unique Combination in a Patient in Association With Multiple Endocrine Neoplasia Type 2B Syndrome With Prolonged Survival.

Head and neck paragangliomas (PGLs) most commonly derive from the carotid body, jugulotympanic, vagal, and laryngeal paraganglia. Thyroid PGLs originate in the inferior laryngeal paraganglion, which may lie inside the thyroid parenchyma. Intrathyroid PGLs are rare with approximately 75 cases reported to date, mostly as solitary lesions. The coexistence of thyroid PGL with medullary thyroid carcinoma (MTC) has not been reported. Here, we report a unique case of intrathyroid PGL concomitant with MTC in the context of multiple endocrine neoplasia type 2B syndrome. Interestingly, the patient showed a prolonged survival with good clinical response to tyrosine kinase inhibitors, despite her advanced metastatic MTC. We discuss the challenges in pathology, differential diagnosis, and genetic background for the development of these thyroid lesions.

High-risk pituitary adenomas and strategies for predicting response to treatment.

High-risk pituitary adenomas are aggressive. They show clinical and imaging features similar to those of carcinomas, including infiltration of the surrounding brain structures, but lack cerebrospinal or systemic metastases. In addition, they display distinct behavior, including tendency for fast growth and frequent recurrences, which are difficult to control. The term "high-risk" adenoma was first introduced in the 4th edition of the World Health Organization Classification of Endocrine Tumors in 2017. Five defined adenoma types belong to this category, including sparsely granulated somatotroph, lactotroph in men, Crooke cell, silent corticotroph, and plurihormonal PIT-1 positive adenomas. The morphological and immunohistochemical characteristics of high-risk adenomas are herein described in detail. In addition, the clinical features and the treatment options are presented. This review focuses on predictive markers assessed by immunohistochemistry, which help clinicians to design the appropriate treatment strategies for high-risk adenomas. Somatostatin receptor status predicts effectiveness of postsurgical treatment with somatostatin analogs, and MGMT expression predicts response to treatment with temozolomide. This comprehensive review presents the clinical and pathological features of high-risk pituitary adenomas, underlines the contribution of immunohistochemistry, and emphasizes the leading role of pathology in the design of optimal clinical management.

Update on pituitary adenomas in the 2017 World Health Organization classification: innovations and perspectives.

The World Health Organization (WHO) classifications of tumors offer invaluable support in the diagnosis of tumors, with every new edition including novel information and diagnostic updates. The new 2017 WHO Classification of Tumors of Endocrine Organs, 4th edition, includes innovations in both terminology and diagnostic guidelines for pituitary adenomas, along with new entities, molecular information, and novel treatment modalities. The recommended reporting system of pituitary adenomas is based on morphology and assessment of the hormonal content by immunohistochemistry. Electron microscopy and immunohistochemistry for Ki-67 and p53 and transcription factors, while presenting additional information, are not recommended for routine diagnosis. Other markers may also yield information of prognostic and predictive significance. In sum, the 2017 WHO classification provides pathologists and clinicians with new and comprehensive information of great use for the diagnosis and treatment of pituitary tumors.

Investigation of somatostatin receptor profile of neuroendocrine carcinomas of the breast.

Carcinomas of the breast with neuroendocrine features are rare primary neoplasms positive for neuroendocrine markers. According to the WHO classification of tumours of the breast they are divided into three morphologically distinct categories. They comprise neuroendocrine tumour (NET), neuroendocrine carcinoma (NEC) and carcinoma with neuroendocrine differentiation (NED). The purpose of this study was to investigate for the first time the full spectrum of sstr expression status in breast carcinomas with neuroendocrine features. Fifteen primary breast carcinomas with histological and immunohistochemical neuroendocrine features were studied. Four of them were classified as NETs and two as NECs, and the remaining 9 as carcinomas with NED. All six types of somatostatin receptor (sstr) types (sstr1, sstr 2A, sstr2B, sstr3, sstr4 and sstr5) were investigated by immunohistochemistry. To assess the distribution and intensity of membranous receptor immunoreactivity, a four-scale scoring system was used. Overall predominant receptors were sstr2A, sstr2B, sstr3 and sstr5 showing the highest membranous staining scores 3+ and 2 + . The sstr1 was not detected. Given that carcinomas with neuroendocrine features represent distinct entities, patients with such tumours may benefit from sstr targeting therapies. Immunohistochemistry for sstrs can predict the effectiveness of administration of SST analogues to those patients, thus contributing to achieve the maximum therapeutic outcome, particularly in NETs and NECs with scores 2+ and 3 + .

Somatostatin receptor profile in pituitary thyrotroph adenomas.

OBJECTIVES: Thyrotroph adenomas are the most infrequent adenohypophysial tumors. Somatostatin (SST) inhibits hormone secretion and suppresses cell proliferation. SST receptors (sstr) belong to a family of 5 types of G-coupled membrane proteins, which show high binding affinity to SST. Currently, SST analogs used to treat pituitary adenomas, have a preferential binding activity to sstr2 and sstr5. The aim of this study was to evaluate the status of all active sstrs on cell membrane of thyrotroph adenomas. PATIENTS: Nine cases of thyrotroph adenomas were studied for all types of sstrs. All patients were clinically associated with hyperthyroidism. The adenomas were initially diagnosed and classified by histology and immunohistochemistry for all pituitary hormones and two of them were examined by electron microscopy. METHODS: For sstr immunohistochemistry, antisera against all sst types (1, 2A, 2B, 3, 4 and 5) were used. To enhance sensitivity, the tyramide amplification technique was applied. This is the first report investigating the full spectrum of sstrs in thyrotroph adenomas by immunohistochemistry. RESULTS: All tumors were immunoreactive for ß-subunit of thyroid-stimulating hormone and for α-subunit of glycoprotein hormones. The sst2A, sst2B and sstr5 were co-expressed in all adenomas. The sstr1 and sstr3 were noted in 8 and sstr4 in 7 adenomas respectively. High scores 2+ and 3+ were prominent in sstr2A, sstr2B, sstr3 and sstr5. High score 3+ for sstr4 was also noted in one tumor, while score 3+ for sstr1 was not observed. CONCLUSIONS: Knowledge of the sstr status may contribute to a better selection of patients, anticipating benefit from treatment with SST analogs. Given that multiligand SST analogs have a broader ability to bind other sstrs, such as sstr1 and sstr3, patients with thyrotroph adenomas expressing these receptors may benefit from novel sstr targeting therapy.

MGMT immunohistochemistry in pituitary tumors: controversies with clinical implications.

INTRODUCTION: Temozolomide (TMZ) is currently considered as a rational therapeutic option for patients with progressively aggressive pituitary adenomas and carcinomas not responding to conventional therapies. Administration of TMZ results in clinical response and improvement in survival of many of these patients depending upon the expression of the DNA repair enzyme O-6 methylguanine DNA transferase (MGMT). Low or negative MGMT immunoreactivity predicts responsiveness to TMZ therapy. Therefore, MGMT serves as a criterion to select candidate patients anticipating response to treatment. MATERIALS AND METHODS: The MGMT expression was investigated in 25 pituitary adenomas with Ki-67 labeling index more that 3% and p53 expression, using various antigen retrieval protocols. After direct application of the antibody, only one adenoma yielded positive for MGMT. However, after pretreatment of tissue sections with antigen retrieval protocols, another 3 adenomas, initially negative turned to positive. CONCLUSIONS: These findings could explain lack of response to TMZ treatment in patients with false negative MGMT immunohistochemistry. Evaluation of tumor samples for MGMT expression should carefully be carried-out using the optimum immunohistochemical protocol to obtain consistent and reliable results that help to identify patients that could respond to TMZ therapy.

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.

The gonadotroph origin of null cell adenomas.

OBJECTIVE: The term "null cell" adenoma was first proposed in 1980 to designate pituitary adenomas lacking clinical, biochemical and morphological markers to disclose their cell origin. DESIGN: The aim of this study was to investigate the presence of α- and ß-gonadotropin subunits in clinically nonfunctioning pituitary tumors, which were initially immunonegative and thus diagnosed as null cell adenomas. For this reason, we reapplied immunohistochemistry using a more sensitive method comprising a tyramide signal amplification technique, combined with a polymer antibody immunohistochemical detection system. RESULTS: With this approach, all these previously negative tumors became positive for α- and ß-gonadotropin hormone subunits. CONCLUSIONS: Our results prove that so-called "null cell" adenomas produce α-SU or/and ß-FSH or ß-LH and therefore are gonadotrph adenomas in origin.

Somatostatin and dopamine receptor expression in neuroendocrine neoplasms: correlation of immunohistochemical findings with somatostatin receptor scintigraphy visual scores.

CONTEXT: The expression of somatostatin (sstr1-5) and dopamine (DR) receptors in neuroendocrine neoplasms (NENs) facilitates diagnosis by tumour visualization with somatostatin receptor scintigraphy (SRS) and directs towards specific treatment with peptide receptor radionuclide therapy (PRRT) with radiolabelled somatostatin analogues. OBJECTIVE: To investigate the co-expression of sstrs, D2R in relation to pre-operative SRSs in NENs. DESIGN: Prospective two-centre study. PATIENTS AND MEASUREMENTS: We analysed pre-operative SRS of 60 patients [44 with gastrointestinal (GI) NENs and 16 with lung NENs] and compared SRS results with immunohistochemical (IHC) reactivity for sstr2, sstr3, sstr5 in sample tissues from primary (n = 54) and metastatic (n = 27) lesions and IHC reactivity for D2R in 23 samples from primary GI-NENs lesions. RESULTS: Sstr2 was the commonest sstr expressed (65·4%) and was co-expressed with sstr3 and sstr5 in 32·1% and 24·7% of the specimens, respectively. In 67 of 81 specimens (82·7%), there was concordance of sstr2 immunohistochemistry with SRS findings (P < 0·001). D2R was expressed in only 8 of 23 (34·8%) GI-NENs while was co-expressed with sstr2 in all cases. SRS grade, as per Krenning scale, was higher in metastatic foci, large-size (>2 cm) tumours and GI-NENs, whereas sstr2 intensity was greater in GI compared to lung NENs. SRS grade showed higher correlation with sstr2 (r = 0·6, P < 0·001) and D2R (r = 0·5, P < 0·001) IHC intensity scores than tumour size (r = 0·4, P < 0·001) and sstr3 (r = 0·4, P < 0·001) intensity score. CONCLUSIONS: Sstr2 IHC expression and SRS are useful tools for the diagnosis and management of NENs because they display a high concordance. IHC expression of DR2 seems to be of potential clinical significance in GI-NENs tumours.

Long-term remission in an aggressive Crooke cell adenoma of the pituitary, 18 months after discontinuation of treatment with temozolomide.

KEY CLINICAL MESSAGE: The clinical course of our patient, who sustained remission status for at least 18 months highlights the chance of long-term hormonal and tumor remission and demonstrates the efficacy and safety of discontinuation of temozolomide therapy. Prospective studies are required in order to define predictors of long-term remission of this promising therapeutic modality.

New horizons in diagnosis and management of endocrine tumors.

Endocrine tumors were considered relatively infrequent neoplasms. However, during the last decades, their frequency gradually increased. The use of imaging techniques, guided FNA biopsy, an endoscope camera in the investigation of endocrine lesions, permits early diagnosis. At the histological level, new applications such as non-biotin containing immunohistochemical detection systems, tyramide amplification method, in situ hybridization, FISH, CGH, and other molecular techniques have provided better knowledge on the protein and molecular background. The investigation of somatostatin and dopamine receptors assists targeted therapy of endocrine tumors. Novel treatment modalities have emerged for the management of pituitary and gastroenteropancreatic tumors respectively. Despite this progress, in some instances, the morphological diagnosis remains questionable. Similarities among normal elements, hyperplastic conditions and benign or malignant lesions can make separation difficult. The "gray zones" representing the overlapping in the sequence of normal parenchyma/ hyperplasia/ adenoma/ carcinoma signify a difficult and controversial diagnostic task, which merits special attention. Furthermore, in most endocrine tumors, the diagnosis of carcinoma is justified only in the presence of local or distant metastases. More precise guidelines are needed, by improving the currently available criteria, to minimize the "gray zones", leading to a more accurate separation of such endocrine lesions.

Highly aggressive pathology of non-functional parathyroid carcinoma.

Parathyroid carcinoma is a rare malignant endocrine tumor accounting for only 0.5% to 5% of all primary hyperparathyroidism. Among these malignancies, only 10-25% are nonfunctioning. After the review of the literature we could only ascertain a number of 25 cases reported worldwide, since 1929, our case being the 26th, but the first with a very aggressive pathology, treated with chemotherapy scheme usually used for neuroendocrine tumors. Considering these facts, every single case presented is a step forward in defying the clinical presentation, for the awareness of the clinicians, and also in establishing standard adjuvant therapies.

EZH2 is regulated by ERK/AKT and targets integrin alpha2 gene to control Epithelial-Mesenchymal Transition and anoikis in colon cancer cells.

Epithelial-Mesenchymal Transition is a good example of cell plasticity. In tumorigenesis, this process has been associated with metastasis. Overexpression of EZH2 has been detected in most malignant human tumors, including colorectal carcinomas. Herein, we provide evidence supporting the idea that oncogenic Epithelial-Mesenchymal Transition in colon cancer cell models is partially controlled by epigenetic factors such as the transcription regulator EZH2. Evaluation of EZH2 mRNA and protein levels revealed overexpression in cell lines with metastatic traits. Analysis of EZH2 mRNA expression was expanded in clinical samples of colon cancer, and high level of EZH2 correlates with appearance of metastasis. Furthermore, inhibition of ERK and AKT pathways in metastatic colon cancer cell lines attenuates EZH2 overexpression. EZH2 promoter analysis illustrates presence of putative AP-1 binding sites and occupancy of transcription factors such as FRA-1 and C-JUN is demonstrated here on EZH2 promoter. Abrogation of EZH2 expression impairs the ability of colon cancer cells to move associated with anoikis in three-dimensional environment. Integrin alpha2 was identified to be a novel EZH2 target by chromatin immunoprecipitation and short hairpin RNA analysis. This study proposes that activation of ERK/AKT pathways and FRA1/C-JUN induce EZH2 overexpression, which results in Integrin alpha2 silencing. Our results show how deregulation of epigenetic factors and mechanisms can affect cancer cell aggressiveness and propose EZH2 as a potential metastasis marker and/or therapeutic target for colorectal cancer treatment.

Case report: Primary pituitary non-Hodgkin's lymphoma developed following surgery and radiation of a pituitary macroadenoma.

OBJECTIVE: Primary central nervous system (CNS) non-Hodgkin's lymphoma is a rarely encountered clinical entity. Here we present a case of a primary CNS diffuse large B-cell non-Hodgkin's lymphoma developed on a previously operated and irradiated pituitary macroadenoma. DESIGN-RESULTS: A 60-year-old woman presented with muscle weakness and eye lid ptosis. Thirty years ago, she was diagnosed with a non-functioning pituitary macroadenoma requiring repeated incomplete operations and conventional radiotherapy and accompanied by partial anterior pituitary deficiency. On admission, the magnetic resonance imaging (MRI) identified a pituitary sellar mass extending into the suprasellar region, compressing the optic chiasm and invading the left cavernous sinus. Following transsphenoidal surgery, the histological investigation revealed the presence of a diffuse large B-cell non-Hodgkin's lymphoma without other loci from the systemic staging. Following chemotherapy and despite a marked resolution of the neoplastic pituitary mass in the post-chemotherapy MRI scan, the patient's course was complicated with consciousness deterioration attributed to epileptic seizures and she died of a hospital acquired infection. CONCLUSIONS: Clinicians should include primary CNS lymphoma in the differential diagnosis of an isolated invasive sellar mass. The possible association of primary CNS lymphoma development with the history of operated and irradiated pituitary adenoma is herein discussed.

Uneventful octreotide LAR therapy throughout three pregnancies, with favorable delivery and anthropometric measures for each newborn: a case report.

INTRODUCTION: The safety of octreotide use, in its short-acting preparation, in pregnancy is still unclear. This report provides the first documentation of uneventful octreotide LAR use during three pregnancies in a woman with bronchial carcinoid-associated adrenocorticotropic hormone-dependent Cushing's syndrome. CASE PRESENTATION: A 25-year-old Arabic woman presented to our emergency department with rapid onset of headache, flaring acne and hirsutism, facial puffiness, weight gain and paroxysmal myopathy, and paranoiac thoughts of rape and sexual intimidation. After undergoing surgical removal of a mass by left lower lung lobectomy, her residual lung disease medical therapy failed. Chronic octreotide LAR injections were initiated as indicated by a positive octreoscan.Follow-up revealed a long-lasting positive response to octreotide. Avidity of octreotide to somatostatin receptor sub-type 2 was later confirmed by a positive somatostatin receptor sub-type 2 in the resected tumor specimen. Against our instructions, the patient had three spontaneous pregnancies leading to delivery of three full-term healthy children while her octreotide LAR therapy continued. CONCLUSION: This case adds more data supporting the potential for the safe use of octreotide and the feasibility of octreotide LAR use during pregnancy, making compliance with the patient's preference not to withdraw octreotide therapy as soon as her pregnancy is confirmed a thoughtful option.

Somatostatin and dopamine receptor profile of gastroenteropancreatic neuroendocrine tumors: an immunohistochemical study.

Somatostatin and its synthetic analogs act through five specific somatostatin receptors (sstr1-5), found on the cell membrane of various tumors, including endocrine ones. Dopamine--a known neurotransmitter--acts through five membranous dopamine receptors (D1R-D5R) which have recently been found to be expressed in endocrine tumors. We evaluated the immunohistochemical expression of the sstrs and D2R in a large series of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A total of 22 (28.94%) well-differentiated NETs (WDNETs), 6 (7.89%) WDNETs of uncertain biology, 26 (34.21%) well-differentiated neuroendocrine carcinomas, and 22 (28.94%) poorly differentiated neuroendocrine carcinomas were studied. Overall, 76.31% of the tumors were positive for different types of sstrs with variable intensity of the membranous staining whereas 36.95% were positive for D2R alone. The sstr2A was the most frequently expressed, followed by sstr2B, sstr1, and sstr5. Co-expression of sstrs and D2R was seen in 88.23% of positive tumors. The high rates of sstr2A and sstr2B and in a lower extent of sstr5 expression are of great importance for more accurate imaging, staging and targeted therapy of the disease. The co-expression of sstrs and D2R in a significant number of the studied cases offers a potential therapeutic alternative for GEP-NETs.

Non-adenomatous sellar lesions: experience of a single centre and review of the literature.

Non-adenomatous sellar lesions represent a diagnostic and occasionally a therapeutic challenge. The purpose of the study was to provide an overview of the clinical and radiographic characteristics of non-adenomatous sellar lesions operated at our department, with emphasis on treatment options. In our transsphenoidal surgical series of 300 cases, 29 non-adenomatous sellar lesions (9.7%) were identified by histology. Medical files and imaging findings were retrospectively analysed. Clinical presentation was usually a result of local mass effect. Imaging features were not always diagnostic. Of 29 non-adenomatous sellar lesions, total tumour excision with transsphenoidal surgery was achieved in 17, and no supplemental treatment was needed. Lesions partially resected were further treated with reoperation, radiation therapy, or medical therapy, tailored to individuals. In our experience, non-adenomatous sellar lesions represent a more prevalent clinical entity than expected. Pituitary surgeons should be aware of their existence to reconstruct treatment strategy, proceeding to adjuvant therapy when necessary.