Neuroendocrine tumors of the thymus and mediastinum

Neuroendocrine neoplasms of the thymus

Neuroendocrine neoplasms of the thymus (tNENs), including typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma, are rare tumors with scarce clinical and pathological data available in the literature. They share many common features with neuroendocrine neoplasms in other organs, such as those in the lungs, while demonstrating some distinct clinical and pathological features. This review aims to give an updated overview of each category of tNENs, focusing primarily on the pathologic diagnosis and differential diagnosis of these tumors.

Immunotherapy in thymic epithelial tumors: tissue predictive biomarkers for immune checkpoint inhibitors

Thymic epithelial tumors (TETs) are rare malignant neoplasms arising in the thymus gland. Nevertheless, TETs, including thymomas (TMs), thymic carcinomas (TCs), and thymic neuroendocrine neoplasms (TNENs), are the most common mediastinal malignancies overall. A multidisciplinary approach is required for the appropriate diagnostic and therapeutic management of TETs. To date, the main therapeutic strategies are largely depended on the stage of the tumor and they include surgery with or without neoadjuvant or adjuvant therapy, represented by platinum-based chemotherapy, radiotherapy or chemoradiotherapy. Immune checkpoint inhibitors (ICIs) are ongoing under evaluation in the advanced or metastatic diseases despite the challenges related to the very low tumor mutation burden (TMB) and the high incidence of immune-related adverse events in TETs. In this regard, predictive impact of tissue biomarkers expression such as programmed cell death ligand-1 (PD-L1), and other emerging biomarkers, as well as their optimal and shared interpretation are currently under evaluation in order to predict response rates to ICIs in TETs.

Is this dyspnea because of coronary artery disease? A rare case report of primary neuroendocrine tumor in anterior mediastinum

INTRODUCTION

Mediastinal neuroendocrine tumors are rare malignancies with aggressive behavior and a grim prognosis. These malignancies often go undetected until they are diagnosed at advanced stages.

CASE REPORT

We present the case of 74 -years old man who was hospitalized because of non-ST elevation myocardial infarction and in case of three vessels coronary artery disease, coronary bypass surgery was planned. During preoperative investigation, computer tomography revealed a huge tumor (20 cm × 11 cm × 21 cm in size) in the anterior mediastinum. Successful simultaneous operation coronary bypass surgery and removal of the mediastinal tumor was performed.

DISCUSSION

Surgery is the treatment of choice for neuroendocrine tumors but the relapse rate ranges between 5% and 30% and is higher (65%) in atypical neuroendocrine tumors and patients with mediastinal node involvement. Despite the poor prognosis of neuroendocrine tumors, the spread to the lymph nodes, the patient continues chemotherapy treatment 49 months after the operation.

Primary neuroendocrine carcinoma of cervical lymph node masquerading as non-Hodgkin lymphoma: A diagnostic challenge

ABSTRACT

A large extended family of tumors classified as neuroendocrine tumors most commonly occurs in the gastrointestinal tract and bronchus pulmonary tree. It is extremely unusual for a primary neuroendocrine tumor to present as a cervical lymph node mass at initial presentation. We discuss the rare case of a 55-year-old man who initially complained of a right neck mass that was misinterpreted as non-Hodgkin lymphoma on fine needle aspiration cytology. By integrating clinical findings, radiography, fine-needle aspiration cytology, histomorphology, and immunohistochemistry analysis, a definitive diagnosis of primary neuroendocrine carcinoma of the cervical lymph node was made. He received chemotherapy and decompressive radiation as treatment. Regarding the course of disease in the present case, the patients underwent a distant subcutaneous metastasis over the right anterior chest wall 10 months after the initial manifestation. The patient is still alive, albeit his general condition has gotten deteriorated, and he is getting regular follow-ups.

PAX1 expression in thymic epithelial neoplasms and morphologic mimics

Thymic epithelial neoplasms are morphologically diverse and can pose a diagnostic challenge that is complicated by a lack of immunohistochemistry (IHC) markers that are entirely sensitive and specific for thymic epithelium. Polyclonal PAX8 is often used in this context, but it is not a specific marker. The PAX1 transcription factor shares significant homology with PAX8 and plays an integral role in thymic development in humans and murine models. This study evaluated the role of PAX1 IHC in differentiating thymic epithelial neoplasms from morphologic mimics on whole slide tissue sections. The PAX1 antibody stained all 74 thymoma cases; however, there was wide variability in staining intensity within each subtype. The antibody was less sensitive in thymic carcinomas and thymic neuroendocrine tumors compared to thymomas and demonstrated weak staining in a subset of morphologic mimics (21 squamous cell carcinomas, 6 pulmonary neuroendocrine tumors, 1 mesothelioma, 1 lymphoblastic lymphoma, and 1 granulosa cell tumor). With a H-score positive threshold of 75, the antibody had 100% specificity, and sensitivities of 92%, 56%, and 47% in thymomas, thymic neuroendocrine tumors, and thymic carcinomas respectively. The PAX1 antibody showed frequent geographic reduction in staining consistent with compromised antigenicity from variable formalin fixation. PAX1 IHC has a moderate-to-high sensitivity for thymic epithelial neoplasms; however, the wide staining variability and fixation effects may lead to difficulty with consistent interpretation. This marker is unlikely to supplant the role of PAX8 in diagnostic practice, but it may be a useful addition to immunohistochemistry panels when evaluating for thymic primary tumors.

A case of alpha-fetoprotein-positive thymic small cell carcinoma: a case report

BACKGROUND

An alpha-fetoprotein (AFP)-positive neuroendocrine tumor of the thymus is a rare thoracic malignancy. Few cases of AFP-positive thymic large cell neuroendocrine carcinoma have been reported, with no known previous report of an AFP-positive thymic small cell carcinoma. We encountered a patient with an AFP-positive small cell carcinoma and report here the clinical course.

CASE PRESENTATION

A 40-year-old man was transferred to our hospital for a large anterior mediastinal tumor and showed an elevated serum AFP level. Computed tomography-guided biopsy results led to diagnosis of small cell carcinoma. Induction chemoradiotherapy was performed before surgery because of pulmonary artery invasion. The response to Induction chemoradiotherapy varied among sites, with the main tumor showing shrinkage and the metastasis site growth. This discrepancy suggested a histologic type unresponsive to or cancer cells potentially resistant to chemotherapy, thus a surgical re-biopsy was performed and histological findings revealed AFP-positive small cell carcinoma. Additional chemotherapy was performed, though could not control cancer progression, and the patient died 8 months after the first medical examination.

CONCLUSIONS

Our present clinical experience indicates the importance of histological examination for determining AFP-positive anterior mediastinal tumor treatment. Although AFP-positive neuroendocrine tumor of the thymus is relatively rarer than germ cell carcinoma, differential diagnosis with use of a histological examination should be considered because of the potentially poorer prognosis. The present clinical findings for an AFP-positive neuroendocrine tumor of the thymus case are considered useful for establishing an optimal treatment strategy in the future.

Epigenetics of Thymic Epithelial Tumors

Thymic epithelial tumors (TETs) arise from the epithelial cells of the thymus and consist in the 1% of all adult malignancies, despite the fact that they are the most common lesions of the anterior mediastinum. TETs can be divided mainly into thymomas, thymic carcinomas, and the rarest ad aggressive neuroendocrine forms. Despite the surgical resection is quite resolving, the diagnosis of TETs is complicated by the absence of symptoms and the clinical presentation aggravated by several paraneoplastic disorders, including myasthenia gravis. Thus, the heterogeneity of TETs prompts the search for molecular biomarkers that could be helpful for tumor characterization and clinical outcomes prediction. With these aims, several researchers investigated the epigenetic profiles of TETs. In this manuscript, we narratively review the works investigating the deregulation of epigenetic mechanisms in TETs, highlighting the need for further studies combining genetic, epigenetic, and expression data to better characterize the different molecular subtypes and identify, for each of them, the most relevant epigenetic biomarkers of clinical utility.

Carcinoid tumors outside the abdomen

Neuroendocrine tumors (NETs) are epithelial malignancies that can arise from multiple tissues. Gastrointestinal (GI) NETs are the most common; in this review of extra-abdominal carcinoid tumors, we focus our discussion on bronchial and thymic carcinoid tumors. Bronchial carcinoid tumors comprise a quarter of all NETs and less than 2% of all lung cancers. Thymic carcinoid tumors are extremely rare, accounting for 5% of thymic tumors. Both bronchial and thymic carcinoid tumors are histologically classified as either typical or atypical based on their mitotic rate (less than 2 or 2-10 mitoses per 10 high-powered fields (HPF), respectively). Both bronchial and thymic carcinoids can present with symptoms of obstruction and potentially carcinoid syndrome. The gold standard of management of bronchial and thymic carcinoid tumors is surgical resection. For patients with advanced disease, first-line systemic therapy is generally somatostatin analog monotherapy with octreotide or lanreotide. In patients with refractory disease, therapy generally involves peptide receptor radioligand therapy, everolimus, or cytotoxic chemotherapy. There are ongoing, prospective trials comparing the mainstays of systemic therapy for these patients, as well as ongoing evaluations of immune checkpoint inhibitors and multi-kinase inhibitors. Prognosis for both bronchial and thymic carcinoid tumors depends on histologic grade, local versus invasive disease, and extent of metastases. Herein we provide a summary of the pathophysiologic and clinical background, the current state of the field in diagnosis and management, and note of key ongoing prospective trials for patients with bronchial and thymic carcinoid tumors.

Pulmonary Large Cell Neuroendocrine Carcinoma

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare subtype of malignant pulmonary tumor. The incidence rate of LCNEC was reported to be 0.3%–3% in lung cancers. Although LCNEC is classified as non-small cell lung cancer (NSCLC), it is more aggressive and malignant than other NSCLC, and its biological behavior is similar to that of small cell lung cancer (SCLC). Most of the LCNEC patients are elderly smoking male and the clinical manifestations are not specific. The imaging manifestations of the tumors are often located in the periphery and the upper lobes, and the enlargement of mediastinal or hilar lymph nodes is common. The diagnosis is mainly based on pathology by the histological features and immunohistochemistry (IHC). Specific neuroendocrine markers such as chromogranin A (CgA), synaptophysin (Syn) and CD56 are usually diffusely positive in LCNEC, and found that insulinoma-associated protein (INSM1) and high rate of Ki-67 are helpful for diagnosis. More differential diagnoses also increase the difficulty of correctly diagnosing LCNEC. The rise of LCNEC molecular typing in recent years may be helpful for diagnosis and subsequent treatment. This review focuses on the epidemiological features, imaging studies, pathology, diagnosis, treatment, and prognosis of LCNEC.

Atypical Carcinoid Syndrome in a Patient Presenting With Pericarditis and Supraventricular Tachycardia: A Case Report

Atypical carcinoids are more uncommon than typical carcinoids, and carcinoid syndrome in general is quite rare. Mediastinal atypical carcinoid is a rare neuroendocrine tumor (NET) that spreads aggressively and rapidly. Morphologically, neuroendocrine tumors are classified into typical carcinoid, atypical carcinoid, small cell carcinoma, and large cell neuroendocrine carcinoma, and the latter two are high-grade tumors. The incidence of atypical carcinoid is rare, and the prognosis is poor, which makes larger trials difficult. It may affect the liver, lungs, or mediastinum with or without metastasis. We present a case of a 47-year-old male patient who presented with chest pain and was found to be in supraventricular tachycardia (SVT) on initial presentation to the hospital. A repeat electrocardiogram (ECG) showed widespread ST-segment elevation. A bedside echocardiogram showed a moderate pericardial effusion, and the patient underwent a coronary angiogram, which showed normal coronary arteries. A computed tomography pulmonary angiogram (CTPA) showed a right mediastinal mass, and the patient was referred to oncology following a discussion in a multidisciplinary team (MDT) meeting. He was commenced on neoadjuvant chemotherapy and has been followed up since in the outpatient clinic. This case is unique due to the initial presentation of supraventricular tachycardia and pericardial effusion.

Thymic neuroendocrine tumors in patients with multiple endocrine neoplasia type 1

OBJECTIVE

MEN1 is associated with an increased risk of developing tumors in different endocrine organs. Neuroendocrine tumors of the thymus (TNETs) are very rare but often have an aggressive nature. We evaluated patients with MEN1 and TNET in three university hospitals in Finland.

DESIGN/METHODS

We evaluated patient records of 183 MEN1-patients from three university hospitals between the years 1985-2019 with TNETs. Thymus tumor specimens were classified according to the new WHO 2021 classification of TNET. We collected data on treatments and outcomes of these patients.

RESULTS

There were six patients (3.3%) with MEN1 and TNET. Five of them had the same common gene mutation occurring in Finland. They originated from common ancestors encompassing two pairs of brothers from sequential generations. The mean age at presentation of TNET was 44.7 ± 11.9 years. TNET was classified as atypical carcinoid (AC) in five out of six patients. One patient had a largely necrotic main tumor with very few mitoses and another nodule with 25 mitoses per 2 mm², qualifying for the 2021 WHO diagnosis of large cell neuroendocrine carcinoma (LCNEC). In our patients, the 5-year survival of the TNET patients was 62.5% and 10-year survival 31.3%.

CONCLUSION

In this study, TNETs were observed in one large MEN1 founder pedigree, where an anticipation-like earlier disease onset was observed in the most recent generation. TNET in MEN1 patients is an aggressive disease. The prognosis can be better by systematic screening. We also show that LCNEC can be associated with TNET in MEN1 patients.

Multiple electrolyte disturbances as the presenting feature of multiple endocrine neoplasia type 1 (MEN-1)

Summary

A 49-year-old teacher presented to his general physician with lethargy and lower limb weakness. He had noticed polydipsia, polyuria, and had experienced weight loss, albeit with an increase in central adiposity. He had no concomitant illnesses and took no regular medications. He had hypercalcaemia (adjusted calcium: 3.34 mmol/L) with hyperparathyroidism (parathyroid hormone: 356 ng/L) and hypokalaemia (K: 2.7 mmol/L) and was admitted for i.v. potassium replacement. A contrast-enhanced CT chest/abdomen/pelvis scan revealed a well-encapsulated anterior mediastinal mass measuring 17 × 11 cm with central necrosis, compressing rather than invading adjacent structures. A neck ultrasound revealed a 2 cm right inferior parathyroid lesion. On review of CT imaging, the adrenals appeared normal, but a pancreatic lesion was noted adjacent to the uncinate process. His serum cortisol was 2612 nmol/L, and adrenocorticotrophic hormone was elevated at 67 ng/L, followed by inadequate cortisol suppression to 575 nmol/L from an overnight dexamethasone suppression test. His pituitary MRI was normal, with unremarkable remaining anterior pituitary biochemistry. His admission was further complicated by increased urine output to 10 L/24 h and despite three precipitating factors for the development of diabetes insipidus including hypercalcaemia, hypokalaemia, and hypercortisolaemia, due to academic interest, a water deprivation test was conducted. An 18flurodeoxyglucose-PET (FDG-PET) scan demonstrated high avidity of the mediastinal mass with additionally active bilateral superior mediastinal nodes. The pancreatic lesion was not FDG avid. On 68Ga DOTATE-PET scan, the mediastinal mass was moderately avid, and the 32 mm pancreatic uncinate process mass showed significant uptake. Genetic testing confirmed multiple endocrine neoplasia type 1.

Learning points

In young patients presenting with primary hyperparathyroidism, clinicians should be alerted to the possibility of other underlying endocrinopathies. In patients with multiple endocrine neoplasia type 1 (MEN-1) and ectopic adrenocorticotrophic hormone syndrome (EAS), clinicians should be alerted to the possibility of this originating from a neoplasm above or below the diaphragm. Although relatively rare compared with sporadic cases, thymic carcinoids secondary to MEN-1 may also be associated with EAS. Electrolyte derangement, in particular hypokalaemia and hypercalcaemia, can precipitate mild nephrogenic diabetes insipidus.

225Ac-DOTATOC-Targeted Somatostatin Receptor α-Therapy in a Patient With Metastatic Neuroendocrine Tumor of the Thymus, Refractory to β-Radiation

ABSTRACT

Somatostatin receptor-targeted α-therapy using α-emitter 225Ac-labeled somatostatin analogs has been suggested as a treatment option in advanced metastatic neuroendocrine tumors (NETs) failing treatment with β-emitters, such as 177Lu or 90Y. Thymus NETs are rare and usually more aggressive than other neuroendocrine tumor entities. We present here a case with β-radiation refractory metastatic thymus NET, who demonstrated an excellent therapy response (molecular and morphological remission, as well as significantly improved clinical symptoms) after 225Ac-DOTATOC-targeted α-therapy, without any adverse effects during the treatment or in the follow-up period.

Locally advanced primary mediastinal atypical carcinoid successfully resected after neoadjuvant treatment: A case report

Neuroendocrine tumors (NETs) are epithelial neoplasms with predominant neuroendocrine differentiation that arise in most organs of the body. Mediastinal NETs are very rare, and account for no more than 5% of all mediastinal tumors. R0 surgery represents the milestone of treatment. Here, we describe a case of a locally advanced primary atypical carcinoid of the mediastinum. This was initially considered inoperable due to infiltration of a great vessel and was successfully resected after neoadjuvant treatment as a result of very extensive surgery. Only through an accurate preoperative diagnosis and good radiological planning is it possible to obtain satisfactory oncological results.

Large cell neuroendocrine carcinoma arising from the anterior mediastinum

Anterior mediastinal large cell neuroendocrine carcinomas (LCNECs) are extremely rare, extremely aggressive malignancies that carry a dismal prognosis. We discuss a woman aged 60 years who presented with a 2-month history of recurrent severe constant epigastric pain. Abdominal examination revealed massive hepatomegaly and a CT scan of the liver confirmed coarse liver lesions. Histology from a liver biopsy was consistent with a large cell (non-small cell) neuroendocrine carcinoma. A CT scan of the chest showed a large anterior mediastinal mass unrelated to the lung, suggesting that the anterior mediastinum was the primary origin of the tumour. The patient was planned to receive platinum/etoposide chemotherapy for a metastatic mediastinal large cell neuroendocrine carcinoma. Unfortunately, her health deteriorated, and she was unfit to undergo any further treatment. She was treated palliatively and died 2 months after the diagnosis.

Atypical Carcinoid Tumor of the Mediastinum Presenting as Cushing's Syndrome in an Otherwise Healthy Young Male

Primary neuroendocrine tumors (NETs) are rare types of malignancies that can have a variety of presentations due to the ubiquitous distribution of neuroendocrine cells within the body. While mediastinal masses are not uncommon, NETs arising from the anterior mediastinum are rare and often originate from the thymus gland. A subset of NETs, atypical carcinoids, are more commonly seen in the lungs or gastrointestinal organs and often present with endocrine syndromes, chiefly Cushing’s syndrome. The behavior of atypical carcinoid tumors within the mediastinum is often aggressive and clinical presentations vary widely. In this report, we describe a case of an atypical carcinoid tumor within the anterior mediastinum in an otherwise healthy young male with signs and symptoms of Cushing’s syndrome.

Endoscopic ultrasound ablation in a patient with multiple metastatic pancreatic tumors from adrenocorticotropic hormone-producing thymic neuroendocrine neoplasm

Adrenocorticotropic hormone (ACTH)-producing neuroendocrine neoplasm (NEN) of the thymus is rare. Lymph nodes and bones are the most common metastatic sites. Most cases present with florid Cushing's syndrome (CS). Here, we reported a 58-year-old woman, who presented with intermittent flush and weight loss. Imaging studies revealed tumors in the mediastinum, pancreas, and bones. Contrast-enhanced harmonic endoscopic ultrasound (EUS) of the pancreatic tumors showed heterogeneous and hyperenhancing characteristics. EUS elastography revealed a heterogeneous stiff pattern. EUS-fine needle biopsy to the pancreatic lesion confirmed the NEN nature. Serum ACTH and cortisol levels were abnormally high. Immunohistochemical staining of the thymic and pancreatic specimens was positive for ACTH. However, the patient did not have obvious CS appearance. The patient underwent surgery, radiation, EUS-guided ethanol injection, and anti-cancer medications, but the disease still progressed. The patient died from infection 16 months after NEN was diagnosed. In conclusion, the pancreas can be a metastatic site for ACTH-producing thymic NEN. EUS-associated procedures can help in the diagnosis and treatment of pancreatic metastatic NEN.

Thymic Epithelial Neoplasms: Radiologic-Pathologic Correlation

Thymic epithelial neoplasms, as classified by the World Health Organization, include thymoma, thymic carcinoma, and thymic carcinoid. They are a rare group of tumors and are often diagnosed incidentally in the work-up of parathymic syndrome, such as myasthenia gravis, or when mass effect or local invasion causes other symptoms. In each of these scenarios, understanding the radiologic-pathologic relationship of these tumors allows clinical imagers to contribute meaningfully to management decisions and overall patient care. Integrating important imaging features, such as local invasion, and pathologic features, such as necrosis and immunohistochemistry, ensures a meaningful contribution by clinical imagers to the care team.

Genomic alterations in thymoma-molecular pathogenesis?

Thymomas and thymic carcinomas (TCs) are neoplasms of thymic epithelial cells. Thymomas exhibit a low mutational burden and a few recurrently mutated genes. The most frequent missense mutation p.(Leu404His) affects the general transcription factor IIi (GTF2I) and is specific for thymic epithelial tumors (TETs). The clinically indolent types A and AB thymomas express the miRNA cluster C19MC. This miRNA cluster known to be the largest in the human genome, is-with expression otherwise restricted mostly to embryonal tissue-silenced in the more aggressive type B thymomas and TCs. Thymomas associated with the autoimmune disease myasthenia gravis (MG) exhibit more frequent gene copy number changes and an increased expression of proteins homologous to molecules that are targets for autoantibodies. TCs, however, display a higher mutational burden, with frequent mutations of TP53 and epigenetic regulatory genes and loss of CDKN2A. The knowledge of molecular alterations in TETs fosters the understanding of their pathogenesis and provides guidance for further studies that may lead to the development of targeted therapies.

Diagnostic challenge in diagnosing bilateral breast metastases from mediastinal neuroendocrine tumor: A case report

Background

Metastatic neuroendocrine tumours (NETs) to the breast are very rare entities.

Case presentation

A 26-year-old lady presented with anterior neck swelling with symptoms of superior vena cava syndrome for 6 months. Imaging study revealed a mediastinal mass which was preceded with core biopsy which was consistent with high-grade small cell NETs. Despite second-line adjuvant chemotherapy and radiotherapy, her disease became advanced which was confirmed via restaging scan. There were bilateral breast lesions discovered during the scan which was deemed to be metastatic NETs histologically. Despite prompt initiation of treatment, she succumbed 1 year after the radiotherapy due to disease progression.

Conclusion

High suspicion of an index is needed for diagnosis when patients with known primary NETs present with suspicious breast lesions. Triple assessment is mandatory, however histopathology assessment and immunohistochemistry staining are the mainstay of diagnosis.

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Metastatic breast neuroendocrine tumours are very rare entities especially when they arise from the mediastinum.

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High suspicion of an index is needed for diagnosis when patients with known primary neuroendocrine tumours presented with suspicious breast lesions.

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Any breast pathology requires a triple assessment including secondary breast neuroendocrine tumours.

Incidence, treatment, and survival analysis in esophageal neuroendocrine carcinoma population

BACKGROUND

As a subtype of esophageal neuroendocrine neoplasms (ENENs), esophageal neuroendocrine carcinoma (ENEC) is rare. ENEC can be poorly differentiated and highly aggressive. This study aims to illustrate the incidence, treatment, and prognosis of ENEC by using a population-based database.

METHODS

We collected clinicopathological data [1975-2016] of ENEC, esophageal adenocarcinoma (EACA), and esophageal squamous cell carcinoma (ESqCC) from the Surveillance, Epidemiology and End Results (SEER) database, and analyzed their incidence, treatment, and prognosis.

RESULTS

A total of 60,238 cases were in our study cohort, including ENEC (n=686), EACA (n=26,575), and ESqCC (n=32,977). The incidence of ENEC in 2016 was 0.044 per 100,000 persons. The tumor grade of ENEC was significantly higher than that of EACA and ESqCC (P<0.001). Both cancer-specific survival (CSS) and overall survival (OS) of ENEC were significantly worse than those of EACA and ESqCC (P<0.001). Kaplan-Meier analysis showed significant improvement of CSS and OS by surgery, radiotherapy, and chemotherapy (all P<0.001). Besides, compared with monotherapies, combinational therapies brought more benefits to both CSS and OS of patients with ENEC.

CONCLUSIONS

Our population-based evidence revealed that ENEC, as a rare cancer, had a worse prognosis, compared with EACA and ESqCC. Surgery, chemotherapy, and radiotherapy can all improve the prognosis of ENEC patients. Combinational therapy can yield a better prognosis than monotherapy.

Effect of video-assisted thoracoscopic surgery on pain stress indicators NO, IL-1β and IL-6 in the treatment of mediastinal tumor in children

This study aimed to investigate the effect of video-assisted thoracoscopic surgery (VATS) on pain stress indicators nitric oxide (NO), interleukin-1β (IL-1β) and IL-6 in the treatment of mediastinal tumor in children, so as to explore the clinical application value of this surgery. A retrospective analysis was performed on 82 children with mediastinal tumor undergoing operation in Children's Hospital Affiliated to Zhengzhou University from January 2012 to January 2016. Among them, 48 children undergoing VATS were enrolled as an observation group, and 34 children undergoing conventional thoracotomy were enrolled as a control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the preoperative and postoperative expression levels of NO, IL-1β and IL-6. The intraoperative clinical data, postoperative pain degree and infection rate were observed and recorded in real time, and then compared between the two groups. Before operation (T₀), there were no statistically significant differences between the two groups in serum NO, IL-1β and IL-6 expression levels, which were lower in the observation group than those in the control group at 12 h (T₁) and 24 h (T₂) after operation (P<0.05). The visual analog scale (VAS) score in the observation group was lower than that in the control group at T₁ (P<0.05). Compared with the control group, the largest blade opening, intraoperative blood loss, drainage duration and postoperative pain degree were significantly improved in the observation group. The postoperative infection rate was 4.17% in the observation group, significantly lower than 17.64% in the control group. VATS is effective for postoperative pain stress indicators and infection control in children with mediastinal tumor, which is therefore more suitable for children with the disease and has a higher clinical value.

Germline Missense Mutation of Deleted in Malignant Brain Tumor 1 (DMBT1) in Familial Mediastinal Neuroendocrine Cancer and in vitro Effects in Thyroid Cancer Cells

BACKGROUND

Neuroendocrine tumors (NETs) rarely occur in the mediastinum and their etiology and pathogenesis are still unclear.

OBJECTIVES

This study assessed inherited or de novo mutations in familial mediastinal NETs.

METHOD

DNA samples from 4 patients were subjected to the whole-exome sequencing, and Sanger sequencing was used to identify Deleted in malignant brain tumor 1 (DMBT1) mutations in all 45 family members.

RESULTS

All patients showed a germline DMBT1 mutation at 4971C. Sanger sequencing data showed that 4 NETs and 2 carriers in the first patient's family and 2 NETs and 4 carriers in the second patient's family, respectively, had this DMBT1 mutation. The in vitro data showed that the ectopic expression of DMBT1 reduced tumor cell viability and migration by arresting the G1/S phase of the cell cycle.

CONCLUSIONS

We identified a germline missense mutation in DMBT1D1657E as a susceptibility gene for familial mediastinal NETs.

Anti-Hu Antibody-Associated Adie's Pupil and Paraneoplastic Sensorimotor Polyneuropathy Caused by Primary Mediastinal Small Cell Carcinoma

We report a woman with unilateral Adie's pupil associated with peripheral sensorimotor polyneuropathy, elevated anti-Hu antibody, and primary mediastinal small cell carcinoma (SCC). To our knowledge, this is the first report of Adie's pupil in a patient with mediastinal SCC. Although rare, Adie's pupil and sensorimotor polyneuropathy may be the first manifestation of cancer. Its rapid recognition facilitates an early diagnosis and treatment.

An overview on the differential diagnostics of tumors of the anterior-superior mediastinum: the pathologist's perspective

The thymus is the main organ in the (anterior) (pre-vascular) mediastinum, playing a central role in the maintenance of both cellular and humoral immunity. The function of the thymus has been long underlooked due to its involution starting during young adulthood and unawareness regarding its immunological function. A variety of primary tumors and inflammatory/reactive/disreactive processes occur in the mediastinum and may involve the anterior-superior compartment and the thymus. Maldevelopment processes also take place in the pre-vascular compartment mediastinum. Although infective diseases do not currently represent the main processes in western countries, they may represent a diagnostic challenge in developing countries. The purpose of this review is to provide a short overview of the main thymic cellular components, their tumors, pseudotumors, in order to provide insights into their clinical setting and the features which assist pathologists in their differential diagnosis (DD). Specific differential diagnostic points are provided, both for "solid" tumors as well as for haematological malignancies, together with a morphological overview of cases of concern that occur in the anterior mediastinum. The main immunohistochemical characteristics of neoplastic/non-neoplastic pathology and updated specific references are also provided.

Type B3 thymoma with marked neuroendocrine differentiation: Report of a case

Thymomas are tumors originating from the thymus epithelial cells and are the most common tumors of the anterior mediastinum. They have been classified into types A, AB, B1, B2, and B3 by the World Health Organization. Type B3 thymoma is composed of epithelial cell sheets with mild to moderate atypia and scant lymphocytes. An association between thymic carcinoma and neuroendocrine differentiation has been observed by some authors. However, cases of type B3 thymoma with neuroendocrine differentiation are very rarely discussed in the literature. A 68-year-old woman was referred to our hospital with an abnormal shadow on a chest roentgenogram. Chest computed tomography showed that the lesion was located in the anterior mediastinum. She underwent surgery, and the tumor was diagnosed as a type B3 thymoma with neuroendocrine differentiation. An extremely rare case of a type B3 thymoma showing neuroendocrine differentiation is presented herein.

Unknown primary large-cell neuroendocrine tumor

Large-cell neuroendocrine tumors (NETs) are poorly differentiated malignancies of rare incidence and aggressive nature. NETs mostly arise in the lung followed by the gastrointestinal tract, although they are potentially ubiquitous throughout the body. Primary unknown NET has a worse prognosis and shorter survival comparing with other NETs, with limited available data in the literature concerning this subgroup. The authors report the case of large-cell NET with supraclavicular lymph node presentation. Total excisional biopsy revealed an enlarged adenopathy 18 × 15 × 10 mm, which was extensively infiltrated by a solid malignant neoplasm composed of large cells with granular chromatin, nuclear pseudo-inclusions, high mitotic index, and focal necrosis, with a Ki 67 index 25-30% and positive immunohistochemical study for the expression of cytokeratin 8/18, chromogranin, synaptophysin, and thyroid transcriptional factor-1 (TTF-1). There was no evidence of primary location apart from two infracentimetric lung lesions that could not be accessed for biopsy and were negative at both somatostatin receptor scintigraphy and positron emission tomography. The NET relapsed with three mediastinal masses, so the patient was started on chemotherapy with carboplatin and etoposide with initial total response. Early progression showed no response to further chemotherapy regimens (temozolomide, oral etoposide); therefore, the patient was treated with local radiotherapy. This patient has an atypical long survival (54 months) compared to the literature data. In fact, there are few long-term survivors of large-cell NET and they are all related to complete surgical resection.

Carcinoid tumors of the thymus and Cushing's syndrome: Clinicopathologic features and current best evidence regarding the cell of origin of these unusual neoplasms

It is uncertain whether thymic neuroendocrine tumors (NET) associated with Cushing's syndrome (CS) produce corticotropin-releasing hormone (CRH) and adrenocorticotropin hormone (ACTH) and whether the thymus contains ACTH and/or CRH cells that could originate NET. The clinicopathologic features of 5 typical (TC) and 6 atypical carcinoids (ATC), 10 additional non-neoplastic thymi, 6 adrenal glands with bilateral nodular hyperplasia and 8 adrenal cortical adenomas were reviewed. Representative slides were immunostained for ACTH and CRH. Four (36.4%) of the 11 patients had CS. The incidence of Masaoka stage IV was higher (p < 0.0001) in patients with ATC than TC. Only 2 (18.1%) of the 11 patients were alive at follow-up. Ten NET were CRH immunoreactive and 6 were ACTH immunoreactive. Thymic NET with CS exhibited stronger immunoreactivity for ACTH and CRH than those without CS. Non-neoplastic thymi exhibited scattered ACTH and CRH immunoreactive cells. Normal adrenal cortex and glands with bilateral nodular hyperplasia showed diffuse CRH immunoreactivity while adrenal adenomas showed no or only focal CRH immunoreactivity. Literature review showed no association between thymic NET and adrenal adenomas. The thymus contains CRH and ACTH immunoreactive cells that are probably the origin of thymic NET. Neoplasms associated with CS exhibit strong immunoreactivity for both hormones, suggesting that CRH probably plays a role in the pathogenesis of CS. As adrenals with bilateral nodular hyperplasia exhibit diffuse CRH immunoreactivity and adrenal cortical adenomas either lack this finding or show few immunoreactive cells, this marker may be useful to distinguish these lesions.

Capecitabine and Temozolomide as a Promising Therapy for Advanced Thymic Atypical Carcinoid

BACKGROUND

Thymic atypical carcinoid (TAC) is a rare thymic neuroendocrine tumor that originates in the neuroendocrine system and lacks a standardized treatment. The combination of capecitabine (CAP) and temozolomide (TEM) is associated with an extremely high and long-lasting response rate in patients with metastatic pancreatic neuroendocrine tumors. However, there is little evidence showing that the CAPTEM regimen is effective for TAC. For patients with unresectable or metastatic atypical carcinoid of the thymus, few treatment options are available, and the treatment efficacy is not satisfactory. To explore the efficacy and safety of the CAPTEM regimen against TAC, we conducted a retrospective review.

PATIENTS AND METHODS

A total of nine patients with advanced atypical carcinoid of the thymus in the China-Japan Friendship Hospital were treated with capecitabine (750 mg/m² twice daily, days 1-14) and temozolomide (200 mg/m² once daily, days 10-14) every 28 days between 2014 and 2018. The disease control rate (DCR), progression-free survival (PFS), and adverse effects after treatment were analyzed. The DCR was calculated by RECIST version 1.1. Progression-free survival was calculated by the Kaplan-Meier survival method.

RESULTS

A total of nine patients (six male and three female) were included. The median age at CAPTEM initiation was 50 years (range, 26-58). The median number of CAPTEM cycles was 8 (range, 3-23). The DCR was 89% (8/9), with eight patients achieving stable disease. Only one patient (11%) showed progressive disease. The median PFS was 8 months. Because we applied vitamin B6 and ondansetron before administering the drugs, the side effects of this regimen were very small. Adverse reactions were all below grade 3 and included myelosuppression and digestive tract reaction.

CONCLUSION

Our results suggest that the CAPTEM regimen may be effective and well tolerated for the treatment of TAC. More evidence is needed to validate the effectiveness of this regimen.

IMPLICATIONS FOR PRACTICE

Capecitabine and temozolomide regimen is effective and well tolerated in patients with advanced thymic atypical carcinoid.