Germ cell tumor in the hypothalamo-neurohypophysial region: clinical features and treatment

Pediatric sellar teratoma - Case report and review of the literature

BACKGROUND

Intracranial teratoma represents a rare neoplasm, occurring predominantly during childhood. Characteristic symptoms depend on the location but are mainly hydrocephalus, visual disturbances, hypopituitarism, and diabetes insipidus. Initial diagnosis can be challenging due to similar radiological features in both teratomas and other lesions such as craniopharyngiomas. Gross total resection is recommended if feasible and associated with a good prognosis.

CASE DESCRIPTION

A 10-year-old girl presented with newly diagnosed growth retardation, fatigue, cephalgia and bilateral hemianopia. Further laboratory analysis confirmed central hypothyroidism and hypercortisolism. Cranial magnetic resonance imaging showed a cystic space-occupying lesion in the sellar and suprasellar compartment with compression of the optic chiasm without hydrocephalus present, suspicious of craniopharyngioma. Subsequently, an endonasal endoscopic transsphenoidal near-total tumor resection with decompression of the optic chiasm was performed. During postoperative recovery the patient developed transient diabetes insipidus, the bilateral hemianopia remained unchanged. The patient could be discharged in a stable condition, while hormone replacement for multiple pituitary hormone deficiency was required. Surprisingly, histopathology revealed conspicuous areas of skin with formation of hairs and squamous epithelia, compatible with a mature teratoma.

CONCLUSIONS

We present an extremely rare case of pediatric sellar teratoma originating from the pituitary gland and a review of literature focusing on the variation in presentation and treatment. Sellar teratomas are often mistaken for craniopharyngioma due to their similar radiographic appearances. However, the primary goal of treatment for both pathologies is to decompress eloquent surrounding structures such as the optic tract, and if applicable, resolution of hydrocephalus while avoiding damage to the pituitary stalk and especially the hypothalamic structures. If feasible, the aim of surgery should be gross total resection.

Neurosurgical Treatment and Outcome of Pediatric Skull Base Lesions: A Case Series and Review of the Literature

INTRODUCTION

Pediatric skull base lesions occur rarely and are of various etiologies. Traditionally, open craniotomy has been the treatment of choice; however, nowadays, endoscopic approaches are increasingly applied. In this retrospective case series, we describe our experience in treating pediatric skull base lesions and provide a systematic overview of the literature on the treatment and outcome of pediatric skull base lesions.

METHODS

We conducted a retrospective data collection of all pediatric patients (<18 years) treated for a skull base lesion at the Division of Pediatric Neurosurgery, University Children's Hospital Basel, Switzerland, between 2015 and 2021. Descriptive statistics and a systematic review of the available literature were additionally conducted.

RESULTS

We included 17 patients with a mean age of 8.92 (±5.76) years and nine males (52.9%). The most common entity was sellar pathologies (n = 8 47.1%), with craniopharyngioma being the most common pathology (n = 4, 23.5%). Endoscopic approaches, either endonasal transsphenoidal or transventricular, were used in nine (52.9%) cases. Six patients (35.3%) suffered from transient postoperative complications, while in none of the patients these were permanent. Of the nine (52.9%) patients with preoperative deficits, two (11.8%) showed complete recovery and one (5.9%) partial recovery after surgery. After screening 363 articles, we included 16 studies with a total of 807 patients for the systematic review. The most common pathology reported in the literature confirmed our finding of craniopharyngioma (n = 142, 18.0%). The mean PFS amongst all the studies included was 37.73 (95% CI [36.2, 39.2]) months, and the overall weighted complication rate was 40% (95% CI [0.28 to 0.53] with a permanent complication rate of 15% (95% CI [0.08 to 0.27]. Only one study reported an overall survival of their cohort of 68% at five years.

CONCLUSION

This study highlights the rarity and heterogeneity of skull base lesions in the pediatric population. While these pathologies are often benign, achieving GTR is challenging due to the deep localization of the lesions and eloquent adjacent structures, leading to high complication rates. Therefore, skull base lesions in children require an experienced multidisciplinary team to provide optimal care.

Pituitary Stalk Thickening: Causes and Consequences. The Children's Memorial Health Institute Experience and Literature Review

BACKGROUND

Pituitary stalk thickening (PST) is a rare abnormality in the pediatric population. Its etiology is heterogeneous. The aim of the study was to identify important clinical, radiological and endocrinological manifestations of patients with PST and follow the course of the disease.

MATERIALS AND METHODS

It is a study conducted in 23 patients (13 boys) with PST with/without central diabetes insipidus (CDI) diagnosed between 1990 and 2020 at Children's Memorial Health Institute (CMHI) in Warsaw, Poland. We analyzed demographic data, clinical signs and symptoms, radiological findings, tumor markers, hormonal results, treatment protocols and outcomes.

RESULTS

The median age at the diagnosis of PST was 9.68 years (IQR: 7.21-12.33). The median time from the onset of the symptoms to the diagnosis was 2.17 years (IQR: 1.12-3.54). The most common initially reported manifestations were polydipsia, polyuria and nocturia (82.6%); most of the patients (56.5%) also presented decreased growth velocity. Hormonal evaluation at the onset of PST revealed: CDI (91.3%), growth hormone deficiency (GHD) (56.5%), hyperprolactinemia (39%), central hypothyroidism (34.8%), adrenal insufficiency (9%), precocious puberty (8.7%). The majority of the patients were diagnosed with germinoma (seventeen patients - 73.9%, one of them with teratoma and germinoma). Langerhans cell histiocytosis (LCH) was identified in three patients (multisystem LCH in two patients, and unifocal LCH in one patient). A single case of atypical teratoid rhabdoid tumor, suspected low-grade glioma (LGG) and lymphocytic infundibuloneurohypophysitis (LINH). The overall survival rate during the observational period was 87.0%.

CONCLUSIONS

The pituitary infundibulum presents a diagnostic imaging challenge because of its small size and protean spectrum of disease processes. Germinoma should be suspected in all children with PST, especially with CDI, even when neurological and ophthalmological symptoms are absent.

Suprasellar Mature Cystic Teratoma Mimicking Rathke's Cleft Cyst: A Case Report and Systematic Review of the Literature

In this article, we present a 31-year-old female who presented with intermittent headache and oligomenorrhea of over 10 years' duration. Imaging revealed a large suprasellar mass with sellar extension. The patient underwent an endoscopic endonasal trans-sphenoidal surgery to resection of the mass. Clinical, radiological, and operative findings from this patient were initially considered to be Rathke's cleft cyst (RCC). However, postoperative histological examinations revealed a mature cystic teratoma. No radiotherapy was performed after surgery. At the most recent follow-up, approximately 1 year later, the patient is doing well with no headache and no recurrence of the teratoma.

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

Intracranial germinomas are rare tumours, usually affecting male paediatric patients. They frequently develop in the pineal and suprasellar regions, causing endocrinological disturbances, visual deficits, and increased intracranial pressure. The diagnosis is established on magnetic resonance imaging (MRI), serum and cerebrospinal fluid (CSF) markers, and tumour stereotactic biopsy. Imaging techniques, such as susceptibility-weighted imaging (SWI), T2* (T2-star) gradient echo (GRE) or arterial spin labelling based perfusion-weighted MRI (ASL-PWI) facilitate the diagnosis. Germinomas are highly radiosensitive tumours, with survival rates >90% in the context of chemoradiotherapy. However, patients with resistant disease have limited therapeutic options and poor survival. The aim of this review is to highlight the genetic, epigenetic, and immunologic features, which could provide the basis for targeted therapy. Intracranial germinomas present genetic and epigenetic alterations (chromosomal aberrations, KIT, MAPK and PI3K pathways mutations, DNA hypomethylation, miRNA dysregulation) that may represent targets for therapy. Tyrosine kinase and mTOR inhibitors warrant further investigation in these cases. Immune markers, PD-1 (programmed cell death protein 1) and PD-L1 (programmed death-ligand 1), are expressed in germinomas, representing potential targets for immune checkpoint inhibitors. Resistant cases should benefit from a personalized management: genetic and immunological testing and enrolment in trials evaluating targeted therapies in intracranial germinomas.

[Treatment outcomes in patients with central nervous system germinoma (neuro-ophthalmic aspects)]

OBJECTIVE

The analyze the neuro-ophthalmic outcomes in patients with pineal and suprasellar germinoma after complex treatment.

MATERIAL AND METHODS

There were 125 patients (88 males, 37 females) with primary CNS germinoma for the period 2008-2017. All patients were divided into 3 groups depending on the tumor localization: pineal area - 62 patients, suprasellar neoplasm - 38 patients, bifocal germinoma - 25 patients. Treatment was performed in accordance with the «Germinoma-2008» protocol. Tumors were histologically patients (partial - 32 cases, subtotal - 16 cases). Surgery was followed by postoperative chemotherapy and stereotactic radiotherapy. The results were evaluated by neuro-ophthalmological examination at all stages of complex treatment.

RESULTS

Pineal germinoma resulted oculomotor and pupillary disorders (58 patients - 94%) and papilledema. The last one completely regressed under the treatment. Partial reduction of oculomotor and pupillary abnormalities occurred throughout chemotherapy (6 patients - 10%). More than half of patients (n=24, 63%) with suprasellar germinoma had visual impairment. Improvement of visual functions including severe visual disturbance was observed in 14 patients (58%). Predominantly, functional recovery occurred under chemotherapy (12 patients - 86%). Bifocal germinoma was followed by various combinations of oculomotor, pupillary and/or visual impairments. We observed regression of only mild visual disorders. Stereotactic radiotherapy did not ensure any changes in neuro-ophthalmic symptoms in all groups.

Clinical management of teratoma, a rare hypothalamic-pituitary neoplasia

Intracranial teratomas are rare and comprise about 0.5 % of all intracranial tumours. Actually, a total of 15 cases of sellar-suprasellar teratoma have been described in the last 24 years. Although rare, hypothalamic-pituitary teratomas should be taken into account in the differential diagnosis of hypothalamic-pituitary region tumours. The current review focuses on the clinical and therapeutic management of pituitary region teratomas. Teratomas occur more frequently in children and young adults than in the older population and in males as compared to females. Symptoms at diagnosis are usually neurological defects, diabetes insipidus and hypopituitarism. Teratoma diagnosis can be suggested though neuroimaging findings. Magnetic resonance imaging remains the preferred modality for assessment of teratoma. Neuro-radiological findings of mixed-density mass, usually with mixed cystic and solid components or inclusions of teeth, fat and calcification can be suggestive. Tumour markers as beta-HCG and alpha-FP can be useful at teratoma diagnosis for distinguishing immature teratomas, mixed GCTs and mature teratomas with immature or malignant components. Optimal treatment for mature teratoma is neurosurgical excision. Radical excision is advocated as recurrence rate for a mature teratoma is extremely low in cases of complete resection and long-term outcome is excellent. During post-treatment follow-up, in cases of healing, according to tumour marker evaluation and contrasted MRI findings, hormone replacement therapy should be considered, also for secondary hypogonadism and GH deficit, with a more intense follow-up. However, as actually few evidence are available, safety data have to be confirmed also trough a surveillance study.

The treatment of cranial germ cell tumours

Germ cell tumours of the central nervous system (CNS) include many subtypes whose response to treatment varies, even though the symptoms and radiological appearances are similar. Five-year survival rates are 96% for germinomas, 100% for mature teratomas, 67% for immature teratomas and 69% for immature teratomas mixed with germinomas; for beta-HCG secreting germinomas the rate is only 38%. Patients with choriocarcinoma, embryonal carcinoma, or yolk sac tumour have the lowest survival rates; patients with germinoma or mature teratoma have longer survival rates. Although a wider resection is associated with a higher rate of survival for patients with non-germinomatous germ cell (NGGC) tumours, to date an aggressive surgical approach has been advocated only for pineal region tumours, but not for hypothalamic/neurohypophyseal tumours. Beside the delayed injury induced by radiotherapy, the late injury induced by chemotherapy is becoming increasingly evident. Cisplatin is considered an indispensable drug, but it may cause renal damage, ototoxicity, peripheral neuropathy and sterility, while etoposide is associated with an excess frequency of second neoplasms. Taking into account all of the published literature, the following therapeutic options are suggested: in pure germinoma tumours (GT) radiotherapy alone will usually ensure adequate control of the disease, and the long-term sequelae may be limited by reducing the dose delivered, as was proposed for germ cell testicular tumours, to 30 Gy to limited fields plus 25-30 Gy to the spinal axis if there is disseminated disease. In cases of recurrence, which should be uncommon, patients may be rescued with both radiotherapy and chemotherapy. In NGGC tumours, the prognosis is more unfavourable and there is often dissemination to the spine at diagnosis; however, the tumour's high chemosensitivity suggests neoadjuvant treatment chemotherapy with cisplatin and etoposide for three cycles followed by consolidation radiotherapy with 40 Gy to the limited fields plus 30 Gy to the spinal axis if disseminated. In our opinion, a higher dose of radiotherapy in cases in which chemotherapy does not achieve a radiological complete remission is not advisable, because very often the residual radiological abnormality does not represent biologically active tumour but differentiated forms such as mature teratoma. The challenge for 2000 is to both cure these patients, and avoid the late and permanent sequelae of radiation and/or chemotherapy that may subsequently impair quality of life.

Occult neurohypophyseal germinomas in patients presenting with central diabetes insipidus

Although neurohypophyseal germinoma is known be a common initial symptom in cases of diabetes insipidus (DI), its radiological detection may take months or years even by a high-resolution magnetic resonance (MR) imaging. The term “occult neurohypophyseal germinoma” denotes such cases, but its clinical picture remains obscure.

Of seven patients with neurohypophyseal germinoma presenting with DI during the last 5 years, three patients showed no evidence of tumor at the onset of DI and were treated as “idiopathic” DI. Neurohypophyseal germinoma was eventually diagnosed in these three patients as the tumor became evident on sequential MR imaging studies and the patients were successfully treated with chemotherapy and radiation therapy. To delineate the clinical features of the occult neurohypophyseal germinoma, the authors analyzed endocrinological aspects and MR images in these patients and compared them with those in two patients with true idiopathic DI and four patients with overt neurohypophyseal germinoma and DI. Nine previously reported cases in the literature were reviewed. During the stage at which the germinoma gave no notable change on MR images, patients often displayed anterior pituitary dysfunction, particularly growth hormone (GH) deficiency, or an elevation of serum or cerebrospinal fluid human chorionic gonadotropin-beta. Preceding the appearance of an obvious tumor mass, a slight swelling of the pituitary stalk with loss of normal hyperintensity of the posterior pituitary lobe was a common finding on MR imaging.

Central DI associated either with an enlarged stalk, decreased GH secretion, or an elevated serum human chorionic gonadotropin-beta should prompt the diagnosis of an occult germinoma.

Granular cell tumor of the pituitary stalk

A 52-year-old woman, who had been treated for Parkinson disease for 2 years, was found to have a suprasellar granular cell tumor. The clinical and pathological features, as well as some of the nosologic problems of this rare tumor of the neurohypophysis are briefly discussed.

Chemotherapy for progressive pilocytic astrocytomas in the chiasmo-hypothalamic regions

Over the past 25 years, we have treated 17 patients with chiasmo-hypothalamic astrocytomas. Before 1988, the initial treatments consisted of surgery and/or radiotherapy, while since 1989, 4 children (1 male, 3 females, aged 3-8 years) were treated primarily with chemotherapy. None of them was associated with neurofibromatosis. After a biopsy of the tumor, the intravenous administration of ranimustine (MCNU; 30-86 mg/m2) and/or nimustine (ACNU; 30.3-64.1 mg/m2) was given without radiation therapy. Chemotherapy was usually given as an out-patient, with a total of 5-13 courses. The total doses of MCNU and ACNU administered ranged from 150 to 570 mg and from 64.8 mg to 100 mg, respectively. After chemotherapy 2 patients showed clinical improvement and tumor regression on neuro-imaging, while one patient showed clinical improvement and tumor size stabilization on neuro-imaging. The remaining one child, however, showed a clinical worsening and tumor progression on neuro-imaging studies. He was thus treated with a second chemotherapy regimen with carboplatin and etoposide, which brought about tumor regression. The acute and subacute toxicity of chemotherapy was mild. All patients are now leading almost normal lives with a median of 43 months after diagnosis. Although a longer and more careful clinical observation is required, the authors conclude that chemotherapy with MCNU and/or ACNU may benefit patients with unresectable pilocytic astrocytoma requiring treatment. The advantages of this therapy include its mild side effects and the lack of any hospitalization in most patients. It may also delay the need for radiation therapy, which can have a deleterious effect on the young developing brain.