Levothyroxine suppressive therapy in differentiated thyroid cancer treatment.

Levothyroxine therapy in management of diferentiated thyroid carcinoma (DTC) has been common practice for decades. Levothyroxine is being administered to patiens with DTC after total thyreoidectomy (with or without postopreative radioiodine treatment) not only to restore euthyroidism but to suppress the production of thyroid-stimulating hormone (TSH) as well because TSH is considered as a growth factor for thyroid follicular cells. However there has been a downside to this threatment recently. The main concerns are the known risks related to iatrogenic subclinical or even mild but clinicaly overt iatrogenic hyperthyroidism. Therefore individualized treatment approach aiming to balance between the risk of tumor recurence and the risks related to hypertyhroidism in view of pateints age, risk factors and comorbidities is essential. Close folow-up is therefore necessary with frequent dose adjustments according to target TSH values published in American Thyroid Association guidelines.

Pitx2 is a useful marker of midgut-derived neuroendocrine tumours - an immunohistochemical study of 224 cases.

Pitx2 is a transcription factor responsible for establishment of the right-left axis and development of the gut and pituitary. In mouse embryos, Pitx2 is expressed in the greater curvature of the stomach and midgut. Previously, Pitx2 was studied in pituitary neuroendocrine tumours but not in other NETs. Pitx2 expression was immunohistochemically assessed in whole sections and tissue microarrays in a cohort of 224 neuroendocrine neoplasms, and was analysed in 29 cases. The cohort included 18 cauda equina NETs, 38 paragangliomas, 98 cases of primary visceral NETs from different organs, 23 metastases of visceral NETs and 47 neuroendocrine carcinomas (NECs). Pitx2 expression was observed in 29.5% (29 of 98) NETs and 14.9% (7 of 47) NECs, but was not observed in any paraganglioma or cauda equina NET. Pitx2 was observed only in tumours of midgut-derived organs, including the small intestine (100%, 20 of 20), appendix (88.9%, eight of nine) and large intestine (9.1%, one of 11 - only caecal NET). The NETs of remaining locations were negative. Pitx2 was 96.7% sensitive and 100% specific for NETs of midgut origin. In NECs, Pitx2 positivity was observed in goblet cell adenocarcinoma (75%, three of four), medullary thyroid carcinoma (42.9, three of seven) and one Merkel cell carcinoma (25%, one of four). In metastatic NETs, Pitx2 was observed in all the tumours originating in the small intestine (n = 17) or caecum (n = 1). No positivity was observed in tumours from other locations (four pancreas, one lung). We observed no correlation between immunoreactivity and mRNA expression. Thus, Pitx2 immunohistochemistry can be helpful in assessing the midgut origin of NETs.

Predictive and prognostic significance of tumour subtype, SSTR1-5 and e-cadherin expression in a well-defined cohort of patients with acromegaly.

In somatotroph pituitary tumours, somatostatin analogue (SSA) therapy outcomes vary throughout the studies. We performed an analysis of cohort of patients with acromegaly from the Czech registry to identify new prognostic and predictive factors. Clinical data of patients were collected, and complex immunohistochemical assessment of tumour samples was performed (SSTR1-5, dopamine D2 receptor, E-cadherin, AIP). The study included 110 patients. In 31, SSA treatment outcome was evaluated. Sparsely granulated tumours (SGST) differed from the other subtypes in expression of SSTR2A, SSTR3, SSTR5 and E-cadherin and occurred more often in young. No other clinical differences were observed. Trouillas grading system showed association with age, tumour size and SSTR2A expression. Factors significantly associated with SSA treatment outcome included age, IGF1 levels, tumour size and expression of E-cadherin and SSTR2A. In the group of SGST, poor SSA response was observed in younger patients with larger tumours, lower levels of SSTR2A and higher Ki67. We observed no relationship with expression of other proteins including AIP. No predictive value of E-cadherin was observed when tumour subtype was considered. Multiple additional factors apart from SSTR2A expression can predict treatment outcome in patients with acromegaly.

Cytokeratin 8/18-negative somatotroph pituitary neuroendocrine tumours (PitNETs, adenomas) show variable morphological features and do not represent a clinicopathologically distinct entity.

AIMS: In somatotroph pituitary neuroendocrine tumours (adenomas), a pattern of cytokeratin (CK) 18 expression is used for tumour subclassification, with possible clinical implications. Rare somatotroph tumours do not express CK 18. We aimed to characterise this subset clinically and histologically. METHODS AND RESULTS: Clinical and pathological data for the study were derived from a previously published data set of a cohort of 110 patients with acromegaly. Data included serum levels of insulin-like growth factor 1 (IGF1), growth hormone (GH), prolactin and thyroid-stimulating hormone (TSH), tumour diameter, tumour invasion defined by Knosp grade and immunohistochemical data concerning the expression of Ki67, p53, E-cadherin, somatostatin receptor (SSTR)1, SSTR2A, SSTR3, SSTR5 and D2 dopamine receptor. Additional immunohistochemical analysis (AE1/3, CK 8/18, vimentin, neurofilament light chain, internexin-α) was performed. CK 18 was negative in 10 of 110 (9.1%) tumours. One of these tumours was immunoreactive with CK 8/18 antibody, while the remainder expressed only internexin-α intermediate filament in patterns similar to CK 18 (perinuclear fibrous bodies). CK-negative tumours showed no significant differences with respect to biochemical, radiological or pathological features. They showed significantly higher expression of SSTR2A compared to the sparsely granulated subtype and significantly lower expression of E-cadherin compared to the non-sparsely granulated subtypes of tumours. The tumours showed divergent morphology and hormonal expression: two corresponded to densely granulated tumours and three showed co-expression of prolactin and morphology of either mammosomatotroph or somatotroph-lactotroph tumours. Four tumours showed morphology and immunoprofile compatible with plurihormonal Pit1-positive tumours. CONCLUSIONS: CK-negative somatotroph tumours do not represent a distinct subtype of somatotroph tumours, and can be further subdivided according to their morphology and immunoprofile.

Scintigraphic evaluation of salivary gland function in thyroid cancer patients after radioiodine remnant ablation.

Radioiodine (131 I, RAI) has traditionally been used in thyroid cancer treatment but its benefit should be balanced against possible risks. Among them, salivary gland dysfunction has often been discussed, although the reported data have been inconsistent. The aim of our prospective study was to evaluate salivary gland function in 31 thyroidectomised patients (6 men, 25 women; median age 52 yr) before and 4-6 months after RAI remnant ablation (RRA), using activity of 3.7 GBq 131 I-NaI. Salivary gland uptake and excretion fractions were quantitatively assessed with 99m Tc - pertechnetate salivary gland scintigraphy. Pre- and post-treatment values were compared using Wilcoxon signed rank test. No statistically significant difference in the pre- and post-treatment values was observed in parotid or submandibular glands uptake, or in the parotid or submandibular excretion fractions. The calculated power for minimum relevant difference of 25% with the sample size of 31 ranged between 86% and 96% for the individual variables, making our negative results reasonably reliable. The results suggest that RRA with the most commonly used activity of 3.7 GBq has no important impact on salivary gland function. Therefore, the concerns about putative salivary gland functional deterioration following RRA are probably unjustified.

Microsurgical versus endoscopic surgery for non-functioning pituitary adenomas: a retrospective study.

AIM: To compare microsurgical technique (mTSS) and endoscopic technique (eTSS) in the treatment of non-functioning pituitary adenomas (NFPAs). METHODS: We retrospectively evaluated the charts of 50 patients who underwent either mTSS or eTSS for NFPA in the Department of Neurosurgery, University Hospital Hradec Kralove from 2013 to 2019. We enrolled all patients who were not treated by postoperative adjuvant radiotherapy and who underwent at least two regular postoperative magnetic resonance imaging (MRI) tests. We compared the groups in terms of the extent of resection, surgery duration, blood loss, complication rate, overall clinical effect on the endocrinological and ophthalmological deficit, and postoperative growth pattern of the residual tumor mass. RESULTS: The mTSS group had significantly shorter surgical time (75 min vs 127 min, P<0.001) and lower perioperative blood loss (156 mL vs 256 mL, P=0.027). The groups did not significantly differ in the extent of resection, overall clinical or hormonal effect, and the complication rate. The extent of resection did not correlate with tumor consistency, while the tumor growth rate did not correlate with age or Ki-67 expression. CONCLUSIONS: There was no major difference between the approaches in surgery radicality or safeness. However, eTSS remains the method of choice due to its potentially higher postoperative preservation of hormonal functions.

Evaluation of expression of somatostatin receptor 1, 2, 3, 5 and dopamine D2 receptor in spindle cell oncocytomas of posterior pituitary.

PURPOSE: Spindle cell oncocytomas (SCOs) are very rare tumors of the posterior pituitary with potential for locally aggressive behaviour. Their treatment includes surgery and possibly radiotherapy, however other options are lacking. Somatostatin receptors (SSTs) are a possible therapeutic target for somatostatin analogues and their expression has been demonstrated recently in closely related pituicytomas, but there are no data about their presence in SCOs. METHODS: We collected five cases of SCO from four patients including one recurrent case. Immunohistochemical detection of TTF1, GFAP, CD68, SST1, SST2, SST3, SST5 and D2 dopamine receptor (D2DR) was performed. Intensity, percentage of positive cells and pattern of expression was evaluated in semiquantitative fashion. Protein expression of SST1-5 and D2DR was further evaluated by western blot. RESULTS: Mean patient age was 61.8 years (range 47-71 years) with male to female ratio 1:1. In one patient, samples from the original tumor and its recurrence 16 years later were assessed. TTF1 was positive in all five cases, no expression of GFAP and CD68 was seen. Immunohistochemical expression of SST1 was noted in 1/5 cases, SST2 in 2/5 cases, including recurrent case but not the original case. SST3 was expressed in 3/5 tumors and D2 dopamine receptor in 4/5 cases. Western blot was successfully performed in four samples. SST2, SST3 and D2DR expression was identified in all the samples, including two cases originally negative for SST2 and one case negative for SST3 by immunohistochemistry. The number of positive cells and level of expression varied among different areas of the same tumors. No expression of SST5 was observed. In the patient with the recurrent tumor, intensity of SST2, SST3 and D2DR expression varied between original tumor and its recurrence. CONCLUSIONS: We demonstrated presence of different SST subtypes and D2DR in spindle cell oncocytomas. The most commonly expressed subtype was SST2 and SST3, while no expression of SST5 was observed. Expression showed spatial heterogeneity and temporal changes as seen in the recurrent case. The biological meaning of SSTs expression in SCOs is unclear as well as whether it may be exploited in treatment of selected cases.

Medically induced CSF rhinorrhea following treatment of macroprolactinoma: case series and literature review.

PURPOSE: Although several reports have addressed cerebrospinal fluid (CSF) rhinorrhea following dopamine agonist (DA) therapy of macroprolactinomas, further study is warranted for this relatively uncommon entity. Toward this aim, our retrospective series and review of literature further clarifies recommendations in treatment of this rare problem. METHODS: We retrospectively reviewed all macroprolactinoma cases in our hospital for a 15-year period. Our systematic search of PubMed identified original articles and reviews of all macroprolactinoma cases with an associated medication-induced CSF leak. RESULTS: Five patients with drug-induced CSF leak were identified; four of these patients received cabergoline therapy an average of 6 weeks before the onset of rhinorrhea and then underwent surgical repair of the CSF leak. Of 35 published studies included, we identified 60 patients with medication-induced CSF leak. Medical therapy included bromocriptine in 34 patients, cabergoline in 21 patients, and use of both DAs in two patients. Three cases did include complete diagnostic and treatment data. Median time from initiation of the DA treatment to occurrence of rhinorrhea was 6 weeks. For CSF rhinorrhea, 49 patients underwent surgical repair (38 by the transnasal approach) and seven patients were treated nonoperatively. CONCLUSION: Baseline skull base erosion in macroprolactinomas in combination with subsequent tumor shrinkage induced by DA therapy may result in spontaneous CSF rhinorrhea. Therefore, such patients should be advised about and monitored for this potential setback. Once CSF leak is diagnosed, prompt treatment must be carried out to avoid infectious complications. Transnasal surgery appears the most effective therapeutic approach.

Treatment of Multifocal Multisystem BRAF Positive Langerhans Cell Histiocytosis with Cladribine, Surgery and Allogenic Stem Cell Transplantation.

Langerhans cell histiocytosis (LCH) is a very rare disease in adults and as well a very rare cause of sellar expansion. The clinical presentation can be heterogeneous, from a single bone lesion to potentially fatal, widespread disease. We describe the difficulties with the diagnosis and treatment of LCH as well as successful treatment with cladribine chemotherapy and allogeneic stem cell transplantation.

[Valvular heart disease in relation to the treatment of hyperprolactinemia with dopamine agonists]. / Chlopenní vady pri lécbe hyperprolaktinemie dopaminovými agonisty.

Adverse effect of dopamine agonists on the heart valves aroused much attention some time ago. Gradually, as data accumulated, the approach to the problem was rationalised and further examinations were only recommended in indicated cases. The paper reviews the current knowledge about the treatment of hyperprolactinemia with dopamine agonists and the risk of valvular disease.Key words: dopamine agonists - ergolines/adverse effects - heart valve diseases - hyperprolactinemia - pituitary neoplasms - prolactinoma.

[Adrenal incidentaloma]. / Incidentalom nadledviny.

Incidentaloma is an adrenal mass discovered serendipitously. Because of increasing use of imaging techniques it is a common finding, being present in more than 1 % of adults. During work-up malignancy has to be ruled out. Classically imaging using CT or MRI is used. Recently PET-CT with FDG has been used more often as its sensitivity for diagnosis of malignancy is about 97 % and specificity 91 %. Hormonal evaluation should diagnose subclinical hypercortisolism. (Dexamethasone Suppression Test is the method of choice). Aldosterone and Renin should be measured only in patients with hypertension and catecholamines in tumours with higher native density than 10 HU. During follow-up repeated CT scan are needed only in selected patients and the need of routine biochemical follow-up has been questioned as well.

[Adrenal insufficiency]. / Adrenální insuficience.

Adrenal insufficiency is a potentially life threatening condition. The paper deals with differential diagnostics and limits of dynamic testing, possibilities of de-escalation of corticosteroid therapy and substitution therapy with glucocorticoids, mineralocorticoids and androgens. New replacement possibilities are mentioned including those in development.

Follicular variant of papillary carcinoma presenting as a hyperfunctioning thyroid nodule.

In this study, we describe a case of papillary carcinoma in a 15-year-old girl who presented with a hyperfunctioning (hot) thyroid nodule and discuss it in the context of current management guidelines for patients with thyroid nodules. In adults, hot nodules rarely require cytologic or histologic evaluation, and hyperthyroidism is often treated with radioiodine (131I). However, in children and adolescents, the malignancy rate for nodules (both cold and hot) is higher and surgery is often necessary. Surgery may serve as a therapy, as well as a diagnostic tool, to treat hot nodules in children and adolescents.

[The occurrence of agranulocytosis due to antithyroid drugs in a cohort of patients with Graves disease treated with radioactive iodine 131I during 14 years]. / Výskyt agranulocytózy po tyreostaticích v kohorte pacientu s Gravesovou nemocí lécených radioaktivním jodem 131I v prubehu 14 let.

INTRODUCTION: Agranulocytosis is a serious complication of antithyroid drugs (ATD) treatment of thyrotoxicosis. The aim of our work was to assess the occurrence of agranulocytosis in Graves disease (GD) patients admitted for radioactive iodine 131I (RAI) treatment to our thyroid unit. PATIENTS AND METHODS: We analyzed retrospectively a cohort of 603 GD patients (500 women and 103 men; mean age 51.5 ± 12.7 years) who received RAI between 1999 and 2012. Of them, 327 (54 %) patients were originally treated with carbimazole (CBZ), 215 (36 %) with methimazole (MMI) and 61 (10 %) with propylthiouracil (PTU). RESULTS: Agranulocytosis due to ATD was the cause of RAI treatment in 7 patients of 603. All of them were women (mean age 48.7 years; range 23-78). In 4 patients, agranulocytosis occurred on MMI treatment, and in 3 patients on CBZ. After recalculation of CBZ to the equipotent dose of MMI, the mean ATD dose was 22.4 mg MMI/day (range 9-40). No agranulocytosis due to PTU was found in our cohort. The time from beginning ATD treatment to agranulocytosis was 20-41 days. In 5 patients there was a development of fever, while in 2 patients the complication was diagnosed from routine blood count. The mean duration of agranulocytosis was 5.9 days (range 4-8). CONCLUSION: Agranulocytosis incidence in our cohort of patients was 1.2 %, while in most reports the prevalence ranged from 0.2 to 0.5 %. In all patients, agranulocytosis occurred early, and in one third it was asymptomatic when found. The aim of our report is to bring attention to a relatively rare, but potentially serious, complication of ATD treatment.

Hand2 Immunohistochemistry in the Diagnosis of Paragangliomas and Other Neuroendocrine Neoplasms.

Hand2 is a core transcription factor responsible for chromaffin cell differentiation. However, its potential utility in surgical pathology has not been studied. Thus, we aimed to investigate its expression in paragangliomas, other neuroendocrine neoplasms (NENs), and additional non-neuroendocrine tumors. We calibrated Hand2 immunohistochemistry on adrenal medulla cells and analyzed H-scores in 46 paragangliomas (PGs), 9 metastatic PGs, 21 cauda equina neuroendocrine tumors (CENETs), 48 neuroendocrine carcinomas (NECs), 8 olfactory neuroblastomas (ONBs), 110 well-differentiated NETs (WDNETs), 10 adrenal cortical carcinomas, 29 adrenal cortical adenomas, 8 melanomas, 41 different carcinomas, and 10 gastrointestinal stromal tumors (GISTs). Both tissue microarrays (TMAs) and whole sections (WSs) were studied. In 171 NENs, previously published data on Phox2B and GATA3 were correlated with Hand2. Hand2 was positive in 98.1% (54/55) PGs, but only rarely in WDNETs (9.6%, 10/104), CENETs (9.5%, 2/21), NECs (4.2%, 2/48), or ONBs (12.5%, 1/8). Any Hand2 positivity was 98.1% sensitive and 91.7% specific for the diagnosis of PG. The Hand2 H-score was significantly higher in primary PGs compared to Hand2-positive WDNETs (median 166.3 vs. 7.5; p < 0.0001). Metastatic PGs were positive in 88.9% (8/9). No Hand2 positivity was observed in any adrenal cortical neoplasm or other non-neuroendocrine tumors, with exception of 8/10 GISTs. Parasympathetic PGs showed a higher Hand2 H-score compared to sympathetic PGs (median H-scores 280 vs. 104, p < 0.0001). Hand2 positivity in NENs serves as a reliable marker of primary and metastatic PG, since other NENs only rarely exhibit limited Hand2 positivity.

Immunoreactivity of HOXB13 in Neuroendocrine Neoplasms Is a Sensitive and Specific Marker of Rectal Well-Differentiated Neuroendocrine Tumors.

HoxB13 is a transcription factor involved in defining of posterior endodermal derivatives, including prostate and rectum. While it is used as a marker of prostatic adenocarcinoma, it has not been studied systematically in neuroendocrine neoplasms. Thus, we performed HoxB13 immunohistochemistry in tissue microarrays and the whole sections of 232 neuroendocrine neoplasms. These included 34 paragangliomas (PGs), 20 cauda equina neuroendocrine tumors (CENETs), 123 well-differentiated neuroendocrine tumors (WDNETs), and 55 neuroendocrine carcinomas (NECs). WDNETs were additionally analyzed with SATB2, and colorectal WDNETs with CDX2 and serotonin immunohistochemistry. In total, HoxB13 immunoreactivity was observed in 95% (19/20) CENETs, 10.6% (13/123) WDNETs, and 12.9% (7/54) NECs. No PGs were positive. Large intestine WDNETs expressed HoxB13 in 68.4% (13/19); five negative tumors originated in cecum and one in rectum. In rectum, 92.9% (13/14) WDNETs expressed HoxB13. HoxB13 was 92.9% sensitive and 100% specific, showing 100% positive predictive value for the rectal origin of WDNET. In NECs, HoxB13 was positive in 15.4% (2/13) GIT tumors and 80% (4/5) prostatic NECs, but in none of urinary bladder NECs (0/8). SATB2 was positive in 17.1% (21/123) WDNETs, including 78.9% (15/19) of colorectal WDNETs, 71.4% (5/7) appendiceal WDNETs, and 2.9% (1/34) small intestine WDNETs. All 4 SATB2-negative large bowel tumors originated in the cecum. When both markers combined, HoxB13+/SATB2+ immunoprofile was seen exclusively in rectal WDNETs (positive predictive value 100%), while HoxB13-/SATB2+ immunoprofile was highly suggestive of the appendiceal origin (positive predictive value 71.4%). Therefore, HoxB13 can be useful as an immunohistochemical marker of rectal WDNETs and prostatic NECs.

Expression of neuroendocrine markers in meningeal and extrameningeal solitary fibrous tumors: a potential diagnostic pitfall.

Solitary fibrous tumors (SFTs) may show unusual morphologies, and in such circumstances, an unexpected immunoprofile can be misleading. Following an index case of myxoid meningeal SFT with a neuroendocrine immunoprofile, we decided to assess a neuroendocrine profile in SFTs from various locations. The cohort of 9 meningeal and 28 extrameningeal SFTs was evaluated for CNS WHO grade (G1-G3) and 4-tiered Demicco risk stratification. Immunohistochemical detection of synaptophysin, chromogranin, INSM1, CD56, and CD57 was performed in each case and semiquantitatively assessed (0: no expression; 1+: <10% positive; 2+: 11-50%; and 3+: >51%); whole sections (meningeal SFTs) or tissue microarray (extrameningeal SFTs) were used for immunohistochemistry. The cohort included 13 men and 24 women. Meningeal SFTs included 5 WHO G1, 3 WHO G2, and 1 WHO G3 tumors. Extrameningeal SFTs included 21 low-risk, 4 intermediate-risk, and 2 high-risk tumors. INSM1 immunoreactivity was observed in 12 of 37 cases (32%; 8 cases 1+, 3 cases 2+, and 1 case 3+); synaptophysin was positive in 6 of 35 cases (19%; 5 cases 1+ and 1 case 2+); CD56 was positive in 20 of 37 cases (54%; 16 cases 1+, 3 cases 2+, and 1 case 3+); and CD57 was expressed in 14 of 36 cases (39%; 5 cases 1+, 4 cases 2+, and 5 cases 3+). Chromogranin positivity was not observed. No significant association was observed between expression of neuroendocrine markers and tumor grade, Demicco risk group or meningeal and extrameningeal location. Extrapleural SFTs showed a tendency for positivity of INSM1 (P = .014, χ2) and CD57 (P = .017, χ2) compared to pleural SFTs.

Phox2B is a sensitive and reliable marker of paraganglioma-Phox2B immunohistochemistry in diagnosis of neuroendocrine neoplasms.

Phox2B is a transcription factor responsible for chromaffin cell phenotype. Although it is used routinely for diagnosis of neuroblastoma, previous reports concerning its utility in the diagnosis of neuroendocrine neoplasms have been conflicting. We assessed Phox2b immunoreactivity in different neuroendocrine neoplasms. Tissue microarrays or whole sections of 36 paragangliomas (PGs), 91 well-differentiated neuroendocrine tumours of different organs (WDNETs), 31 neuroendocrine carcinomas (NECs), and 6 olfactory neuroblastomas (ONBs) were stained with Phox2B antibody (EP312) and GATA3. The percentage of positive cells and intensity was analysed using H-score. Phox2B immunoreactivity was seen in 97.2% (35/36) PGs, 11% (10/91) WDNETs, 9.7% (3/31) NECs, and 16.7% (1/6) ONBs. PGs were significantly more often positive (p < 0.001, χ2) than other neuroendocrine tumours, showing highest H-score (mean 144.9, SD ± 75.1) and percentage of positive cells (median 81.3%, IQR 62.5-92.5%). Compared to Phox2B-positive WDNETs, PGs showed significantly higher H-score (median 145 vs 7.5, p < 0.001) and percentage of positive cells (median 82.5% vs 4.5%, p < 0.001). Phox2B positivity was 97.2% sensitive and 89% specific for the diagnosis of PG. GATA3 was 100% sensitive and 88% specific for the diagnosis of PG. When combined, any Phox2B/GATA3 coexpression was 97.1% sensitive and 99.1% specific for the diagnosis of paraganglioma. Widespread Phox2B immunoreactivity is a highly characteristic feature of PGs and it can be used as an additional marker in differential diagnosis of neuroendocrine tumours.

Cauda equina neuroendocrine tumors show biological features distinct from other paragangliomas and visceral neuroendocrine tumors.

Cauda equina neuroendocrine tumors (CENETs) are neoplasms of uncertain histogenesis with overlapping features between those of paragangliomas (PGs) and visceral neuroendocrine tumors (NETs). We have explored their biological relationship to both subsets of neuroendocrine neoplasms. The clinical and radiological features of a cohort of 23 CENETs were analyzed. A total of 21 cases were included in tissue microarrays, along with a control group of 38 PGs and 83 NETs. An extensive panel of antibodies was used to assess epithelial phenotype (cytokeratins, E-cadherin, EpCAM, Claudin-4, EMA, CD138), neuronal and neuroendocrine features (synaptophysin, chromogranin A, INSM1, neurofilaments, NeuN, internexin-α, calretinin), chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase), and possible histogenesis (Sox2, T-brachyury, Oct3/4, Sox10). The cohort included 5 women (22%) and 18 men (78%). The average age at the time of surgery was 48.3 years (range from 21 to 80 years). The average diameter of the tumors was 39.27 mm, and invasion of surrounding structures was observed in 6/21 (29%) tumors. Follow-up was available in 16 patients (median 46.5 months). One tumor recurred after 19 months. No metastatic behavior and no endocrine activity were observed. Compared to control groups, CENETs lacked expression of epithelial adhesion molecules (EpCAM, CD138, E-cadherin, Claudin-4), and at the same time, they lacked features of chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase). We observed no loss of SDHB. Cytokeratin expression was present in all CENETs. All the CENETs showed variable cytoplasmic expression of T-brachyury and limited nuclear expression of Sox2. These findings support the unique nature of the neoplasm with respect to NETs and PGs.

Dopamine 2 receptor expression in various pathological types of clinically non-functioning pituitary adenomas.

Clinically non-functioning pituitary adenomas account for about one-third of pituitary tumors. The majority of them are pathologically classified as gonadotropinomas or null-cell adenomas without hormonal expression. The rest represent silent corticotroph adenomas and plurihormonal tumors. Conservative therapy with dopamine agonists is effective in some cases only depending on the expression of dopamine 2 receptors (D2R). The aim of this study was to quantitatively estimate D2R expression in clinically non-functioning pituitary adenomas and correlate the results with adenoma type according to pathological classification. Out of the 87 adenomas investigated, 63 expressed gonadotropins, 7 were silent corticotroph adenomas, 7 were plurihormonal tumors, and only 6 did not express any pituitary hormone on immunohistochemical investigation. With the use of the reverse transcriptase PCR technique, D2R mRNA was expressed in all adenomas with very heterogeneous quantity. The expression was very low in corticotroph adenomas (relative median quantity after normalization to housekeeping gene 0.01) and lower in plurihormonal tumors (median 0.4) than in gonadotroph (median 1.3) and null-cell adenomas (median 1.9). The difference between corticotroph adenomas and plurihormonal tumors in comparison with other pathological types was statistically significant. The expression of D2R did not depend on the presence or absence of gonadotropins. We conclude that D2R expression is very low in corticotroph adenomas and significantly lower in plurihormonal tumors. The positivity of gonadotropins does not predict the D2R quantity.