Synchronized multiple regression of diagnostic radiation-induced rather than spontaneous: disseminated primary intracranial germinoma in a woman: a case report

Abstract

IntroductionExamples of the spontaneous regression of primary intracranial germinomas can be found in the literature. We present the case of a patient with disseminated lesions of primary intracranial germinoma which synchronously shrunk following diagnostic irradiation. We will discuss whether this regression was spontaneous or radiation-induced.Case presentationA 43-year-old Japanese woman presented to our hospital complaining of memory problems over a period of one year and blurred vision over a period of three months. Following magnetic resonance imaging, she was found to have a massive lesion in the third ventricle and small lesions in the pineal region, fourth ventricle, and in the anterior horn of the left lateral ventricle. Prior to an open biopsy to confirm the pathology of the lesions, she underwent a single cranial computed tomography scan and a single cranial digital subtraction angiography for a transcranial biopsy. Fourteen days after the first magnetic resonance image - 12 and eight days after the computed tomography scan and digital subtraction angiography, respectively - a pre-operative magnetic resonance image was taken, which showed a notable synchronous shrinkage of the third ventricle tumor, as well as shrinkage of the lesions in the pineal region and in the fourth ventricle. She did not undergo steroid administration until after a biopsy that confirmed the pathological diagnosis of pure germinoma. She then underwent whole craniospinal irradiation and went into a complete remission.ConclusionsIn our case report, we state that diagnostic radiation can induce the regression of germinomas; this is the most reasonable explanation for the synchronous multiple regression observed in this case of germinoma. Clinicians should keep this non-spontaneous regression in mind and monitor germinoma lesions with minimal exposure to diagnostic radiation before diagnostic confirmation, and also before radiation treatment with or without chemotherapy begins.

Perifocal Inflammatory Reaction with Volume Fluctuation Caused by Diagnostic Radiation-Induced Regression in Germinoma Makes Histological Diagnosis Difficult despite Its Disappearance following Treatment: A Significant Pitfall and Countermeasures to It

“…Lymphocytic hypophysitis in children is very rare, and a coincidence with a germinoma has not been described from a histopathological perspective [5] . DRIR-related fluctuation of the tumor volume disguised germinoma as inflammation, although DRIR is a characteristic of germinoma [15,16] .…”

“…Analysis of cerebrospinal fluid (CSF) detected a high level of placental alkaline phosphatase (PLAP) [14] but not of human chorionic gonadotropin β-subunit or α-fetoprotein, which indicated the neurohypophyseal lesion as germinoma and brought the patient from successful radiochemotherapy up to complete remission. The volume fluctuation of the lesion was presumably caused by diagnostic-radiation-induced regression (DRIR) [15,16] . PIR adjacent to germinoma (PIRAG) with DRIR completely disappeared following treatment.…”

“…2 a, c). Because diagnostic radiation can induce the regression of germinoma [15,16] , this DRIR suggested the lesion as germinoma. Thus, fluctuation of the tumor volume is observed not only in inflammation, but also in germinoma.…”

Pretreatment Diagnosis of Suprasellar Papillary Craniopharyngioma and Germ Cell Tumors of Adult Patients

“…This radiosensitive tumor can shrink significantly from any low-dose irradiation, such as brain CT, and can regrow in some seeding areas. 19,20 Due to gravity in upright position, the infundibular recess of the third ventricle is one of the most common sites for deposition of a seeding lesion. This seeding hypothesis of suprasellar GCT can corroborate the therapeutic results of pediatric GCT with low-dose irradiation including the ventricular system.…”

Is Regression of Intracranial Germinoma Spontaneous or Diagnostic Radiation-Induced? A Case Report

“…We previously reported a case of synchronized multiple regression of primary intracranial germinoma [7]. In that report, we suggest the synchronized multiple regression as a diagnostic radiation-induced regression (DRIR).…”