Radiologic features of primary intracranial ectopic germinomas

Abstract

Rationale:Germinomas are sensitive to radiation therapy and chemotherapy; therefore, correct imaging diagnosis is crucial for them. However, the imaging findings of germinomas originating from off-midline regions displayed different patterns from those originating from midline areas.Patient concerns:The objective of this study is to describe the radiologic features of primary ectopic germinoma. We reviewed the MR and CT findings of 12 patients with histologically proven off-midline ectopic germinomas with off-midline locations.Interventions:All of these patients underwent conventional MR images and 3 of them underwent diffusion images. Additional CT images were available in 3 patients. Analysis was focused on the shape and entity of tumors in images, signs of hemiatrophy, and the involvement of fibers in diffusion images.Outcomes:Well-defined (8/12) and ill-defined margin masses (4/12) were identified according to the shape of the mass. Multicystic masses were seen in 11 of the 12 patients. The solid component of the tumors had a high density (3/3) with calcifications (2/3) on CT images, iso- to hypointensity in T2WI (11/12) and restricted diffusion on apparent diffusion coefficient (ADC) maps (3/3). Hemiatrophy was observed in 5 cases and progressive hemiatrophy was observed in 1 case. Other signs included mild peritumoral edema (10/12), and hydrocephalus (7/12). Additionally, infiltration of the corticospinal tract (CST) was identified on diffusion tensor imaging (DTI) (2/2).Lessons:The results indicate that multicysitic entities and hypointensities in solid components on T2WI and hemiatrophy are the imaging features of ectopic germinomas. DTI has potential for assessing CST involvement.

Bifocal germinoma of the septum pellucidum and the sellar-supra-sellar region: An uncommon presentation for a rare tumor

“…These findings were not related to calcifications or hemorrhagic components. Slight restriction diffusion in our case was in concordance with the few reported cases [8,10].…”

“…However, they share a few common imaging features with ectopic IGs, different from those originating from sellar/suprasellar and pineal regions: well-defined margins, isointense on T1 WI, iso/hypointense on T2 WI, contain multiple cysts which tend to be large because of the minimal or nonspecific clinical signs and symptoms. The solid part of the lesion presents moderate or strong enhancement and cysts-walls enhancement and mild peritumoral edema are present [[7], [8], [9]]. Ectopic IGs have a more marked male predominance than midline IGs and present predominantly as a single tumor [8].…”

“…The solid part of the lesion presents moderate or strong enhancement and cysts-walls enhancement and mild peritumoral edema are present [[7], [8], [9]]. Ectopic IGs have a more marked male predominance than midline IGs and present predominantly as a single tumor [8]. The reported cases of SP germinomas (SPG) present numerous and large (50–60 mm) cysts, marked enhancement, without associated hemorrhage or calcifications as demonstrated by NCCT and T2* sequence.…”

Ectopic Germinoma: A Delayed Diagnosis With Serial Magnetic Resonance Imaging Features

“…Other symptoms include headache, vomiting, mental retardation, and precocious puberty. However, these symptoms do not correlate with the average size of germinoma [7], as seen in our patient. His first presenting complaint was mild hemiparesis and did not correlate with the size of the tumor, which appeared as foci of hyperintense signal on T2-weighted imaging.…”

“…Retrospectively, there was slight asymmetry in the patient's lateral ventricle which progressed to merely a 3 mm difference, which may or may not be due to the presence of minimal atrophy. In advanced disease, basal ganglia germinoma has been described in the literature [7,9,[15][16][17]. Typically, it can present as a heterogeneous mass and mostly contains hemorrhage, cyst, and necrosis.…”