Pituitary tumours - a large retrospective single-centre study of over 2300 cases. Experience of a tertiary reference centre.

INTRODUCTION: Pituitary adenomas (PAs), also known as a pituitary neuroendocrine tumours (PitNET), are usually benign tumours of the anterior lobe of the pituitary gland and account for the third most common intracranial neoplasm. The most common type of pituitary adenoma is lactotroph adenoma, in which dopamine agonists are the first-line treatment. Nevertheless, in selected cases surgery or even radiotherapy may be required. In the current study, we aimed to analyse all patients who underwent surgery due to intrasellar mass in order to evaluate frequency of particular pituitary tumours, clinical diagnosis, and pathology findings. MATERIAL AND METHODS: We retrospectively analysed all cases of patients consecutively operated due to intrasellar mass between 1st January 2010 and 31st December 2018 at the Department of Neurosurgery, Military Institute of Medicine in Warsaw, Poland. RESULTS: Our database included 2348 cases: 1390 women (59.2%) and 958 men (40.8%). The mean age for women was 48.4 years (SD ± 15.72; median 49) and for men 50.9 years (SD ± 14.94; median 53). In our cohort we found: 869 gonadotroph and null cell adenomas, 751 somatotroph and mammosomatotroph adenomas, 386 corticotroph adenomas, 71 plurihormonal adenomas, 59 craniopharyngiomas, 44 lactotroph adenomas, 18 purely thyrotroph adenomas, and other rare cases of pituitary tumours including one pituitary carcinoma metastasising to the liver (corticotroph origin). CONCLUSIONS: We provide a comprehensive analysis of both clinical and pathological findings of the largest cohort of patients operated on for pituitary adenomas in one tertiary reference centre. To the best of our knowledge, this is the largest up-to-date published analysis in our country.

Double pituitary adenomas in a large surgical series.

PURPOSE: To explore the incidence of double pituitary adenomas in a tertiary center for pituitary surgery and asses their clinical, imaging and histopathological features. METHODS: The medical records of the patients operated on for pituitary tumors at the Department of Neurosurgery of Military Institute of Medicine in Warsaw, Poland between the years 2003 and 2018 were retrospectively analyzed. Among the 3270 treated patients, the diagnosis of double pituitary adenoma was established in 22 patients. Clinical, laboratory, detailed histopathological and diagnostics imaging data were collected and analyzed. RESULTS: There were 21 cases of synchronous and one case of asynchronous double pituitary adenoma. The main clinical finding was acromegaly (12/22) followed by Cushing's disease (3/22). The diagnosis of synchronous double pituitary adenoma was suspected in the preoperative MRI in 11 patients. In the remaining patients the diagnosis of contiguous double pituitary adenoma was confirmed in the histopathological examination. There was no predilection for gender and the mean observation time was 74.2 months. In one case of Cushing's disease the occurrence of double pituitary adenoma led to the initial failure of achieving hormonal remission. One patient presented with double pituitary adenomas as a manifestation of Carney complex. CONCLUSIONS: Double pituitary adenoma is a rare entity that can pose a significant challenge especially in the setting of Cushing's disease. Careful inspection of preoperative MRI and diagnostic work-up before transsphenoidal surgery and thorough histopathological microscopic examinations with immunohistochemical staining for all pituitary hormones is essential for establishing the diagnosis of double pituitary adenoma.

Lineage-dependent role of miR-410-3p as oncomiR in gonadotroph and corticotroph pituitary adenomas or tumor suppressor miR in somatotroph adenomas via MAPK, PTEN/AKT, and STAT3 signaling pathways.

PURPOSE: miR-410-3p plays opposite roles in different cancers and may act as an oncomiR or tumor suppressor miR. The purpose of this study was to assess the role of miR-410-3p in somatotroph, gonadotroph, and corticotroph pituitary adenomas. METHODS: Tissue samples were obtained from 75 patients with pituitary adenoma. miR-410-3p expression was assessed using qRT-PCR performed on RNA isolated from fresh frozen samples. In vitro experiments were performed on cell lines derived from somatotroph (GH3), gonadotroph (RC-4B/C), and corticotroph (AtT-20) pituitary tumors. Cells were transfected with synthetic mimic of miR-410-3p or non-targeting scrambled-miR control. Subsequently, proliferation assays and transwell invasion assays were performed. The expression of cyclin D1, E1, and B1 in cells after transfection was determined using qRT-PCR. The activation of MAPK, PTEN/AKT and STAT3 signaling pathways were assessed using western blot. RESULTS: We have found that the level of expression of miR-410-3p differs in particular types of pituitary adenomas. miR-410-3p significantly upregulates proliferation and invasiveness of RC-4B/C and AtT-20 cells, while inhibiting GH3 cells. We observed that the levels of cyclin B1 upon transfection with miR-410-3p mimic were increased in RC-4B/C and AtT-20, yet decreased in GH3 cells. We have shown that miR-410-3p promoted the activation of MAPK, PTEN/AKT, and STAT3 signaling pathways in RC-4B/C and AtT-20 cells, but suppressed their activity in GH3 cells. CONCLUSIONS: miR-410-3p acts as an oncomiR in gonadotroph and corticotroph adenoma cells, while as a tumor suppressor miR in somatotroph adenoma cells.

Subtemporal Approach for Gross Total Resection of Retrochiasmatic Craniopharyngiomas: Our Experience on 30 Cases.

BACKGROUND: Surgical treatment of retrochiasmatic craniopharyngiomas is associated with higher rates of complications, mortality, failure of complete removal, and recurrence compared with craniopharyngiomas located elsewhere. These tumors lie behind the optic chiasm and when large can extend upward into the third ventricle and downward along the brain stem, making their adequate exposure challenging. Most of the proposed techniques either use a translamina terminalis route or require wide bony exposures. In this study, we assessed the feasibility of a subtemporal approach for achieving gross total resection of retrochiasmatic craniopharyngiomas. METHODS: Thirty patients with retrochiasmatic craniopharyngioma underwent surgery via a subtemporal approach. The technique and surgical and preoperative and postoperative endocrinologic outcomes are described in detail. RESULTS: Gross total resection was achieved in all cases. The average tumor volume was 7.59 mL. The average postsurgical observation time was 73.8 months. During this time, 3 recurrences were observed (10.7%). The perioperative mortality was 6.6%. The pituitary stalk was preserved in 13 cases. Partial preservation of the pituitary stalk did not offer any advantage in terms of pituitary function. No postoperative vision worsening or new fixed neurologic deficits were observed. Among the 22 patients with preoperative vision impairment, 18 reported a significant improvement. The most common abnormalities within the temporal lobe on the side of the exposure seen on control magnetic resonance imaging were mild temporal horn enlargement (13 cases) and T2 hyperintensity (7 cases). CONCLUSIONS: A subtemporal approach can be an attractive alternative approach to accessing retrochiasmatic craniopharyngiomas. Outcomes are comparable to those associated with other widely used and time-consuming exposures.

Negative Correlation Between Hepatitis C Virus (HCV) and Let-7 MicroRNA Family in Transplanted Livers: The Role of rs868 Single-Nucleotide Polymorphism.

BACKGROUND Genetic alterations of TGF-ß pathway members, including its transmembrane receptor, TGFBR1, may influence the course of HCV infection. Rs868 is a single-nucleotide polymorphism of the 3'UTR region of TGFBR1, located in a binding site for the conserved let-7/miR98 microRNA family. Previously, we demonstrated a favorable course of hepatitis C recurrence after liver transplantation in rs868 AG genotype of the transplanted liver when compared to rs868 AA. The aim of the present study was to confirm the biological effect of rs868. MATERIAL AND METHODS HepG2 cell line was transfected with luciferase vectors cloned with 3'UTR of TGFBR1 gene encompassing different rs868 alleles. Post-transplant liver biopsies from 61 patients with HCV-related end-stage liver disease were evaluated histopathologically and analyzed for the expression of TGFBR1 mRNA, let-7/miR98 microRNAs, HCV RNA load, and rs868 genotype. RESULTS Luciferase expression was significantly lower in the A allele-containing vector. TGFBR1 mRNA and HCV RNA load were correlated negatively with let-7/miR98 microRNAs and this correlation was significantly stronger for rs868 AG compared to AA genotype. A strong positive correlation was demonstrated between TGFBR1 and HCV in both genotypes. In AG heterozygotes, let-7/miR98 microRNAs showed a strong negative correlation with periportal or periseptal interface hepatitis (Ishak A score). CONCLUSIONS There is a negative correlation between let-7/miR98 microRNAs and HCV viral load and TGFBR1 mRNA after liver transplantation. In the rs868 AG heterozygotes, this correlation was stronger and there was a negative correlation between let-7/miR98 and Ishak A score, which is in concordance with the previously demonstrated protective role of this genotype in post-transplant hepatitis C recurrence.

Increased expression of the microRNA 106b~25 cluster and its host gene MCM7 in corticotroph pituitary adenomas is associated with tumor invasion and Crooke's cell morphology.

PURPOSE: MCM7 (minichromosome maintenance complex component 7), a DNA replication licensing factor, is a host gene for the oncogenic miR-106b~25 cluster. It has been recently revealed as a relevant prognostic biomarker in a variety of cancers, including pituitary adenomas. The purpose of this study was to assess whether miR-106b~25 and MCM7 levels correlate with tumor invasiveness in a cohort of ACTH-immunopositive adenomas. METHODS: Tissue samples were obtained intraoperatively from 25 patients with pituitary adenoma. Tumor invasiveness was assessed according to the Knosp grading scale. MCM7, Ki-67 and TP53 levels were assessed by immunohistochemical staining, while the expression of miR-106b-5p, miR-93-5p, miR-93-3p and miR-25-3p were measured using quantitative real-time PCR performed on RNA isolated from FFPE tissues. RESULTS: We have found a significant increase in MCM7 and Ki-67 labeling indices in invasive ACTHomas. Moreover, MCM7 was ubiquitously overexpressed in Crooke's cell adenomas. The expression of miR-93-5p was significantly elevated in invasive compared to noninvasive tumors. In addition, all four microRNAs from the miR-106b~25 cluster displayed marked upregulation in Crooke's cell adenomas. Remarkably, MCM7 and miR-106b-5p both strongly correlated with Knosp grade. A combination of MCM7 LI and miR-106b~25 cluster expression was able to accurately differentiate invasive from noninvasive tumors and had a significant discriminatory ability to predict postoperative tumor recurrence/progression. CONCLUSIONS: miR-106b~25 and its host gene MCM7 are potential novel biomarkers for invasive ACTH-immunopositive pituitary adenomas. Additionally, they are both significantly upregulated in rare Crooke's cell adenomas and might therefore contribute to their aggressive phenotype.

Intraparenchymal mesenchymal chondrosarcoma of the frontal lobe--a case report and molecular detection of specific gene fusions from archival FFPE sample.

Mesenchymal chondrosarcoma is a rare tumor of cartilaginous origin characterized by its bimorphic pattern composed of highly undifferentiated small round cells separated by islands of well-differentiated hyaline cartilage. It exhibits higher malignancy and earlier occurrence in comparison to classic chondrosarcomas. Recently identified HEY1-NCOA2 and IRF2BP2-CDX1 gene fusions confirm their distinct molecular origin and pose a promising diagnostic marker. The majority of cases arise from craniofacial bones. In this study, we present a rare case of mesenchymal chondrosarcoma encompassed within the brain parenchyma of the frontal lobe without any dural or bone attachment. We demonstrate histopathological findings and confirm the HEY1-NCOA2 gene fusion in a formalin-fixed paraffin-embedded archival sample using simple reverse transcription polymerase chain reaction (RT-PCR) method. IRF2BP2-CDX1 gene fusion was absent in the analyzed sample. The clinical follow-up is also presented with a review of treatment modalities for this entity.

Association of 49245A>G (rs868) polymorphism in the 3'UTR of donor TGFBR1 gene with course of hepatitis C following orthotopic liver transplantation.

BACKGROUND: Terminal hepatitis C is one of the leading indications for orthotopic liver transplantation (OLT). However, hepatitis C virus (HCV) reinfection occurs in almost all recipients and usually leads to progressive fibrosis and graft failure. Transforming growth factor-b (TGF-ß) plays a part in transplanted liver cirrhosis, but nothing is known about the possible role of genetic diversity of TGF-ß receptor system. Therefore, the aim of our study was to investigate whether genetic variation in 3' untranslated region (3'UTR) of TGF-ß receptor type I (TGFBR1) gene is associated with recurrence and severity of hepatitis C and liver fibrosis following OLT in HCV-infected patients. MATERIAL AND METHODS: The study group included 95 chronic hepatitis C patients following OLT. The recipients and donors were genotyped for 49245A>G (rs868) and 51976G>A (rs334349) single nucleotide polymorphisms (SNP). RESULTS: Donor rs868 AA genotype was strongly associated with worse clinical course of recurrent hepatitis C. The rs868 AA group displayed more severe symptoms of hepatitis C during the follow-up and the fibrosis score in this group was significantly higher 3 years after OLT. CONCLUSIONS: Clinical course of hepatitis C after OLT may depend on donor rs868 SNP located in TGFBR1 3'UTR.

mTOR is frequently active in GH-secreting pituitary adenomas without influencing their morphopathological features.

Initiating factors and mechanisms of tumor formation are poorly understood in nonfamilial pituitary adenomas. Alteration of intracellular pathways is an underlying event in numerous neoplasms. Among them, excessive activation of mammalian target of rapamycin (mTOR) pathway and its two main regulators, Akt and Erk, has been detected frequently in solid tumors. This study tests the activation of mTOR pathway in pituitary adenomas and its influence on their morphopathological features. Fifty-three pituitary adenomas were fresh frozen after surgery and analyzed by western blotting using phospho-specific antibodies. The impact of Akt and Erk activation on mTOR pathway was assessed in five primary cultures derived from the excised adenomas using selective kinase inhibitors. Statistical correlations of size, volume, Ki-67 %, Knosp's grading, and somatostatin receptor (SSTR) expression with the activation of mentioned kinases was performed. GHomas showed the highest frequency (71 %) and level of mTOR pathway activity comparing to other adenomas (33 %). No significant correlation was found between mTOR activation and any of the morphopathological features in the studied samples. mTOR kinase phosphorylation was independent of Erk and Akt in primary cultures. Erk activity was significant in all types of adenomas but was the highest in control samples. Its phosphorylation correlated inversely with the Knosp's grading in nonfunctional pituitary adenomas and directly with somatostatin receptor subtype 2 A expression in GHomas. Presented data point to the noteworthy mTOR activity in GHomas. However, the lack of correlation with morphopathological features, its independence of Erk and Akt phosphorylation, and high level of Erk activity in control pituitary necessitate further research for clarifying the role of these pathways in pituitary adenomas.

Fluvastatin increases tyrosinase synthesis induced by alpha-melanocyte-stimulating hormone in B16F10 melanoma cells.

The aim of this study was to evaluate the effect of fluvastatin on the alpha-melanocyte-stimulating hormone-mediated increase in tyrosinase activity in the melanoma B16F10 cell line and to establish whether Akt and extracellular signal-regulated kinase (Erk) inhibition is involved in tyrosinase synthesis after fluvastatin administration. Fluvastatin modulates alpha-melanocyte-stimulating hormone induced melanogenesis by increasing tyrosinase mRNA production, as shown by real time PCR, or tyrosinase protein synthesis, as presented by western blot technique. The stimulatory effect of fluvastatin on melanogenesis was, in part, induced by modulation of cell proliferation (decreased melanoma cell proliferation in G2/M phase) and possibly decrease of Akt. These findings indicate that fluvastatin increases tyrosinase synthesis induced by alpha-melanocyte-stimulating hormone in B16F10 cells and reveal an unknown effect of statin use: their influence on melanin production.

Fluvastatin increases tyrosinase synthesis induced by UVB irradiation of B16F10 melanoma cells.

Statins are widely used to lower plasma concentrations of lipids, e.g. cholesterol. One of the main effects of statin treatment is inhibition of hydroxymethyl glutaryl-coenzyme A reductase. The role of fluvastatin, a frequently used statin, was examined in potential modulation of tyrosinase (key enzyme of melanogenesis) synthesis. Levels of tyrosinase mRNA induced by UVB irradiation of B16F10 melanoma cell line were measured by real time PCR. Fluvastatin increases tyrosinase mRNA production induced by UVB irradiation in B16F10 melanoma cell line. Fluvastatin treatment may potentially influence melanin synthesis and protection against UV irradiation.

[Factors affecting melanogenesis and methods used for identification of pigmentation disorders]. / Czynniki modulujace melanogeneze oraz metody identyfikacji zaburzen barwnikowych.

Melanins are pigments widely distributed in living organisms. In humans melanin is synthetised in the retina, choroid and epidermis. Melanins fulfil a protective function and are responsible for the color of eyes, skin and hair. Melanogenesis is a process undergoing in specialized organelles of melanocytes--melanosomes. After synthesis, melanin is transported to target cells--keratinocytes. The key enzyme of the melanin synthesis pathway is tyrosinase. Many agents used in the treatment of hyperpigmentation act as tyrosinase inhibitors. Depigmenting agents and those increasing melanin synthesis are used in medicine and cosmetology. Also natural plant melanins extracted from e.g. Nigella sativa, have interesting effects on mammalian cells. In the current review paper we present methods used for identification of melanin and melanocytes in diagnostics of disorders affecting melanogenesis process.