Molecular Pathology and Targeted Therapies for Personalized Management of Central Nervous System Germinoma

Targeted therapy for non-small-cell lung cancer: New insights into regulated cell death combined with immunotherapy

Non-small-cell lung cancer (NSCLC), which has a high rate of metastatic spread and drug resistance, is the most common subtype of lung cancer. Therefore, NSCLC patients have a very poor prognosis and a very low chance of survival. Human cancers are closely linked to regulated cell death (RCD), such as apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis. Currently, small-molecule compounds targeting various types of RCD have shown potential as anticancer treatments. Moreover, RCD appears to be a specific part of the antitumor immune response; hence, the combination of RCD and immunotherapy might increase the inhibitory effect of therapy on tumor growth. In this review, we summarize small-molecule compounds used for the treatment of NSCLC by focusing on RCD and pharmacological systems. In addition, we describe the current research status of an immunotherapy combined with an RCD-based regimen for NSCLC, providing new ideas for targeting RCD pathways in combination with immunotherapy for patients with NSCLC in the future.

Novel therapeutic approaches for pediatric diencephalic tumors: improving functional outcomes

Pediatric diencephalic tumors represent a histopathologically and molecularly diverse group of neoplasms arising in the central part of the brain and involving eloquent structures, including the hypothalamic-pituitary axis (HPA), optic pathway, thalamus, and pineal gland. Presenting symptoms can include significant neurological, endocrine, or visual manifestations which may be exacerbated by injudicious intervention. Upfront multidisciplinary assessment and coordinated management is crucial from the outset to ensure best short- and long-term functional outcomes. In this review we discuss the clinical and pathological features of the neoplastic entities arising in this location, and their management. We emphasize a clear move towards 'function preserving' diagnostic and therapeutic approaches with novel toxicity-sparing strategies, including targeted therapies.

Update on MRI in pediatric intracranial germ cell tumors-The clinical and radiological features

Intracranial germ cell tumors (iGCTs) are uncommon brain tumors that mainly occur in children. Differing in histology, location, and gender of the patients, iGCTs are often divided into germinomas and non-germinomatous germ cell tumors (NGGCTs). Early diagnosis and timely treatment are crucial to iGCTs, the subtypes of which have substantial variations. This review summarized the clinical and radiological features of iGCTs at different sites, and reviewed the recent advances in neuroimaging of iGCTs, which can help predict tumor subtypes early and guide clinical decision-making.

Neoplasms and tumor-like lesions of the sellar region: imaging findings with correlation to pathology and 2021 WHO classification

The sellar region represents a complex anatomical area, composed of multiple structures of different embryological derivation, including the skull base and the pituitary gland, along with vascular, nervous, and meningeal structures. Masses arising in this region include benign and malignant lesions arising from the pituitary gland itself, but also from vestigial embryological residues or surrounding tissues, that may require different therapeutic approaches. While assessing sellar region masses, the combination of clinical presentation and imaging features is fundamental to define hypotheses about their nature. MR represents the imaging modality of choice, providing information about the site of the lesion, its imaging features, and relation with adjacent structures, while CT is useful to confirm the presence of lesion calcifications or to reveal tumor invasion of bony structures. The aim of this pictorial review is to provide an overview of the common neoplasms and tumor-like conditions of the sellar region, according to the 2021 WHO Classification of Tumors of the Central Nervous System (fifth edition), with an emphasis on the radiologic-pathologic correlation. After a brief introduction on the anatomy of this region and the imaging and pathological techniques currently used, the most relevant MRI characteristics, clinical findings, and pathological data, including histologic and molecular features, will be shown and discussed, with the aim of facilitating an appropriate differential diagnosis among these entities.

Histogenesis of intracranial germ cell tumors: primordial germ cell vs. embryonic stem cell

INTRODUCTION

Intracranial germ cell tumor (iGCT) is a rare disorder and often occurs during childhood and adolescence. iGCTs are frequently localized in pineal region and hypothalamic-neurohypophyseal axis (HNA). In spite of well-established clinical and pathological entity, histogenesis of iGCTs remains unsettled. Current theories of histogenesis of iGCTs include germ cell theory (from primordial germ cells (PGCs) of aberrant migration) and stem cell theory (transformed embryonic stem (ES) cells). In order to comprehend the histogenesis, we revisit the origin, migration, and fate of the human PGCs, and their transformation processes to iGCT.

DISCUSSION

In "germ cell theory," transformation of ectopic PGCs to iGCT is complex and involves multiple transcription factors. Germinoma is derived from ectopic PGCs and is considered a prototype of all GCTs. Non-germinomatous germ cell tumors (NGGCTs) develop from more differentiated counterparts of embryonic and extra-embryonic tissues. However, there is a distinct genomic/epigenomic landscape between germinoma and NGGCT. ES cells transformed from ectopic PGCs through molecular dysregulation or de-differentiation may become the source of iGCT. "Stem cell theory" is transformation of endogenous ES cells or primitive neural stem cell to iGCTs. It supports histological diversity of NGGCTs because of ES cell's pluripotency. However, neural stem cells are abundantly present along the subependymal zone; therefore, it does not explain why iGCTs almost exclusively occur in pineal and HNA locations. Also, the vast difference of methylation status between germinoma and NGGCT makes it difficult to theorize all iGCTs derive from the common cellular linage.

CONCLUSION

Transformation of PGCs to ES cells is the most logical mechanism for histogenesis of iGCT. However, its detail remains an enigma and needs further investigations.

Diagnosis and Management of Pineal Germinoma: From Eye to Brain

Pineal germinomas can be very complex in terms of presentation, diagnosis, and management. This review attempts to simplify this complexity in an organized manner, addressing the anatomic relationships that provide the basis for the uniqueness of pineal germinoma. Ocular findings and signs and symptoms of elevated intracranial pressure are the keys to suspecting the diagnosis and obtaining the necessary imaging and cerebrospinal fluid studies. Other symptoms can suggest spread beyond the pineal region. Surgery may only be needed to obtain tissue for a definitive diagnosis, as germinoma is highly responsive to chemotherapy and focused radiation therapy. Hydrocephalus, usually related to tumor obstruction of the cerebral aqueduct, may also need to be addressed. Outcome for pineal germinoma is usually excellent, but relapse can occur and may require additional intervention. These issues are detailed in this review.

PINEAL GERMINOMA PRESENTED WITH PARALYSIS OF UPWARD GAZE AND DIABETES INSIPIDUS

Intracranial germ cell tumors (GCTs) include two categories: germinoma and non germinoma. The pineal gland and suprasellar are the most common site of involvement. The patient is a 14-year-old boy who presented with paralysis of upward gaze, polyuria, polydipsia and diplopia. Examination of vertical eye movements was impaired. Puberty then progressed to stage 3 of Marshall - Tanner and had stopped. In laboratory studies, the patient had anterior hypopituitarism and diabetes insipidus (DI). In pituitary and hypothalamic MRIs, a mass-like enlargement of the pituitary stalk and pineal region was seen, but due to the small size of the lesions, stereotactic biopsy was not possible. During this time, the patient developed recurrent attacks of hydrocephalus. Serum and CSF β-subunit of Human chorionic gonadotropin levels were negative. Treatment was not started because different lesions could cause disease in this area. After one year, a biopsy was performed and the germ cell tumor was diagnosed. Chemotherapy was started and after treatment the vision disorder and diplopia disappeared, but DI and pituitary dysfunction remained. Treatment of intracranial germinoma is multidisciplinary. GCTs are very sensitive to radiation therapy. They are treated with combination of chemotherapy, radiotherapy, surgery, endocrine therapy and have a good prognosis.

Pituitary stalk thickening in patients under 18 years of age - the most common causes and diagnostic procedures

INTRODUCTION

Pituitary stalk thickening (PST) is a rare abnormality in children, and it may be challenging due to its diverse clinical picture.

AIM OF THE STUDY

The aim of the study is to summarize the data on the causes and diagnostic procedures of PST.

MATERIAL AND METHODS

Papers were searched in the PubMed database identifying published randomized clinical trials, reviews, systematic reviews, meta-analyses, and case reports.

RESULTS

The most common causes of a thickened pituitary stalk in children are germ cell tumours (GCTs), Langerhans cell histiocytosis (LCH), and lymphocytic infundibulo-neurohypophysitis (LINH). Neurosarcoidosis, pituitary tuberculosis, granulomatosis, or specific inflammations were only reported in the paediatric population as case studies. PST mainly affects teenagers and is often detected with brain magnetic resonance imaging (MRI) in patients with central diabetes insipidus (CDI). It is not possible to differentiate the causes of PST with the use of the MRI image alone. Although various biochemical and oncological markers and other imaging tests are used, the diagnosis of PST remains a significant diagnostic challenge for clinicians. The final diagnosis is made based on histopathological examination. The indications for a biopsy are not uniform. Most experts, including the authors of the 2021 British consensus, recommend biopsy in the case of PST with a stalk lesion diameter ≥ 6.5-7 mm.

CONCLUSIONS

The differential diagnosis of PST is a challenge. The diagnostic and treatment strategy should be individually adapted. Patients should be diagnosed in large clinical centres with experience in this field.