Primary Diffuse Chiasmatic Germinomas: Differentiation from Optic Chiasm Gliomas

Abstract

Primary germ cell tumors confined to the optic nerves and chiasm without suprasellar extension are uncommon. These tumors appear similar to chiasmatic gliomas on both computed tomography and magnetic resonance imaging, potentially resulting in treatment errors if the diagnosis is based on radio-logic criteria alone. Unlike chiasmatic gliomas, suprasellar germinomas characteristically present with a clinical triad of endocrine abnormalities, diabetes insipidus, and visual complaints. We report the case of a 9-year-old boy who presented with a 5-month history of fatigue, 16-pound weight gain, polydipsia, polyuria, visual complaints, and intermittent headache. Imaging studies demonstrated findings consistent with a glioma of the chiasm with infiltration into the optic tracts. At surgery, the chiasm and optic tracts were diffusely enlarged with no other suprasellar abnormalities. Biopsy specimens were characteristic of germ cell tumor. Based on this result, the patient received a treatment regimen different from that used at our institution for chiasmatic gliomas. We feel it is imperative to biopsy chiasmatic lesions that radiologically appear to be gliomas if symptoms do not adhere to the classical clinical presentation.

Outcome of Vision Impairment and Diabetes Insipidus in Suprasellar Region Germinoma

“…Suprasellar germinomas are called neurohypophyseal germinomas because they grow in a line of the hypothalamic-pituitary stalk-neurohypophysis, i.e., the nerurohypophysis [1]. Optic nerve germinomas that oc-cur in the optic chiasm and the optic nerve are rarely reported [5][6][7][8][9][10][11][12] and differentiating between images of optic nerve germinoma and neurohypophyseal germinoma may be difficult when a tumor is large [8]. In other words, it may not be clear whether the site of the tumor origin is the optic chiasm and the optic nerve or the hypothalamus.…”

“…No detailed cases of visual impairment preceding DI in suprasellar germinomas have been reported in the past. When a tumor is not limited to the optic nerve, as in optic nerve germinoma, visual impairment precedes DI [8]. This is because tumor cells infiltrate the optic nerve more so than the nerurohypophysis.…”

Optic chiasmatic-hypothalamic gliomas: Is tissue diagnosis essential?

“…Tekkok et al [23] have reported a case of OCHG presenting as a huge intrasellar mass resembling a pituitary adenoma radiologically. Wilson et al [24] have described a case of suprasellar germinoma mimicking OCHG and have emphasized the requirement of histological confirmation.…”

Primary intrinsic optic chiasm germinoma

“…Our literature review found reports of seven male patients only. [1][2][3][4][5][6] We present a young woman with a primary intrinsic optic chiasm germinoma. To our knowledge, this is the first report of a woman with this disease.…”