Germ cell tumors of the central nervous system originating from non-pineal regions: CT and MR features

A clinical approach to parasellar lesions in the transition age

Many reviews have summarised the pathology and management of the parasellar region in adult patients, although an analysis of these aspects in the transition years, from puberty onset to the age of peak bone mass, has been lacking. A comprehensive search of English-language original articles, published from 2000 to 2020, was conducted in the MEDLINE database (December 2019 to March 2020). We selected all studies regarding epidemiology, diagnosis and management of the following parasellar lesions: germinoma, craniopharyngioma, Langerhans cell histiocytosis, optic glioma, hypothalamic hamartoma, tuber cinereum hamartoma, cranial chordoma, Rathke cleft cyst, hypophysitis and hypothalamitis during the transition age from childhood to adulthood. In the present review, we provide an overview of the principal parasellar lesions occurring in the transition age. Symptoms are usually a result of the mass effect of the lesions on nearby structures, as well as anterior pituitary deficits. Diabetes insipidus occurs frequently in these patients. In this age group, pubertal developmental disorders may be more evident compared to other stages of life. Parasellar lesions in the transition age mostly include neoplastic lesions such as germinomas, hamartomas, optic gliomas, craniopharyngiomas Langerhans cell histiocytosis and chordomas, and rarely inflammatory lesions (hypophysitis, hypothalamitis). There are limited data on the management of parasellar lesions in the transition age. Endocrine evaluation is crucial for identifying conditions that require hormonal treatment so that they can be treated early to improve the quality of life of the individual patient in this complex age range. The clinical approach to parasellar lesions involves a multidisciplinary effort.

Primary cranial vault germinoma in a 23-year-old man: illustrative case

BACKGROUND

Germinoma is the most common type of germ cell tumor that develops intracranially. Germinomas usually grow in the midline structures, such as the pineal and suprasellar regions, and are rarely found in other locations. To the best of the authors’ knowledge, no previous research has reported on growth of this tumor in the cranial vault.

OBSERVATIONS

The authors reported an unusual case of primary cranial vault germinoma in a young adult. Macroscopically, the tumor had a solid-soft consistency and grayish color with brownish spots on the surface. The histological examination revealed anaplastic cells with round, hyperchromatic, pleomorphic nuclei; prominent nucleoli; and abundant, clear cytoplasm, arranged in lobules and sheets that were infiltrated by lymphocytes and separated by fibrous connective tissue. These findings were consistent with the histopathological characteristics of germinoma.

LESSONS

Primary cranial vault germinoma is a unique tumor because no previous research has reported any growth in that location. It should be considered one of the differential diagnoses of lesions located over the cranial vault. Histopathological examination is still the primary modality for diagnosing these tumors and excluding other differential diagnoses.

Primary cerebellar germinomas of the posterior fossa

Primary cerebellar germinomas, in the absence of germ-cell tumours outside the nervous system or elsewhere in the cranial cavity and CSF pathways, are exceptional; only two previous cases have been reported in the literature. Two personal observations are described from our 20-year records of intra-axial posterior fossa tumours. The patients were a 32-year-old man and a 17-year-old woman with a clinical history of posterior fossa tumour, studied by computed tomography. The first patient with slight cerebellar signs had a small right hemispheric cerebellar tumour, and the other had a left cerebellar mass with hydrocephalus and progressive intracranial hypertension. Both were treated by tumour removal and irradiation to the whole posterior fossa. The survival times were 58 and 49 months, respectively. The diagnosis of primary cerebellar germinoma cannot be suspected before pathological confirmation. The clinical, neuroradiological and surgical findings are non-specific and quite similar to those of other malignant cerebellar tumours, such as anaplastic gliomas or metastases. Surgery and radiotherapy ensure adequate tumour control in the early stages; cases of recurrence or disseminated disease may be treated by irradiation and chemotherapy.

Radiological Features of Germinoma Arising From Atypical Locations-Three Case Reports-

Three cases of intracranial germinoma arising from atypical locations occurred in 13-, 22-, and 28-year-old males. The location of the tumor was the corpus callosum (2 cases) and the temporal lobe. Computed tomography and magnetic resonance imaging showed all three tumors had a largest dimension, including the internal cyst, of over 6 cm, and the cysts were larger than 2.5 cm. Radiotherapy and chemotherapy caused all tumors to disappear. Large tumor and large cyst are features of germinoma arising from atypical locations.