Basal ganglia germinomas in children. Four clinical cases and a literature review

Precise detection of the germinomatous component of intracranial germ cell tumors of the basal ganglia and thalamus using placental alkaline phosphatase in cerebrospinal fluid

PURPOSE

The disadvantages of biopsy for lesions in the basal ganglia and thalamus include a risk of various complications, difficulty in selecting the target tissue in some cases due to indistinct neuroimaging findings and limited availability of sample tissue. Placental alkaline phosphatase (PLAP) plays a decisive role in the diagnosis and management of intracranial germ cell tumors (IGCTs) in the basal ganglia and thalamus. The present study aimed to demonstrate the ability, specificity, and optimal use of PLAP values obtained from cerebrospinal fluid (CSF).

METHODS

Twenty patients with lesions in the basal ganglia and thalamus were enrolled in this study: 11 had IGCTs and 9 had non-IGCTs. The values of PLAP and other established tumor markers in the CSF were measured in all patients before treatment.

RESULTS

The mean follow-up period was 76.0 months (range, 3-168) for all lesions. PLAP was elevated in all 11 patients with IGCTs in the basal ganglia or thalamus, whereas none of the patients with non-IGCT exhibited elevated PLAP. Thus, the sensitivity and specificity of PLAP were both 100%.

CONCLUSION

Our data demonstrated that the PLAP value can specifically identify the germinomatous component even in cases of IGCTs in the basal ganglia or thalamus with high sensitivity and specificity. PLAP is undoubtedly beneficial for the safe and timely detection of the germinomatous component of IGCTs in the basal ganglia and thalamus, because reliance on PLAP measurement enables us to avoid invasive surgical procedures and facilitates the prompt initiation of chemoradiation therapy.

Germinomas of the basal ganglia and thalamus: Four case reports

BACKGROUND

The early diagnosis of basal ganglia and thalamus germinomas is often difficult due to the absence of elevated tumor markers, and atypical clinical symptoms and neuroimaging features.

CASE SUMMARY

Four male children aged 8 to 15 years were diagnosed with germinomas in the basal ganglia and thalamus by stereotactic biopsy from 2017 to 2019. All patients developed hemiplegia except patient 4 who also had cognitive decline, speech disturbance, nocturnal enuresis, polydipsia, polyuria, precocious puberty and abnormalities of thermoregulation. All four cases were alpha-fetoprotein and beta-human chorionic gonadotrophin (β-HCG) negative except patient 3 who had slightly elevated β-HCG in cerebrospinal fluid (CSF). No malignant cells were detected in the patients’ CSF. Brain magnetic resonance imaging findings were diverse in these patients with the exception of the unique and common characteristics of ipsilateral hemisphere atrophy, especially in the cerebral peduncle. All patients were diagnosed with germinomas of the basal ganglia and thalamus by stereotactic brain biopsy.

CONCLUSION

Stereotactic brain biopsy is necessary to confirm the diagnosis of ectopic germinomas. Serial neuroimaging studies can not only differentiate disease but also determine the biopsy site.

A single-center study of treatment outcomes of pediatric basal ganglia germinoma in Taiwan

PURPOSE

A basal ganglia (BG) germinoma is a rare tumor, and the optimal treatment remains unknown. We evaluated the clinical outcomes of treatment of BG germinoma in pediatric patients in Taiwan.

METHODS

We retrospectively reviewed the medical records of 34 children with BG germinoma who were treated with radiotherapy (RT) at Taipei Veterans General Hospital between 1989 and 2016. The median follow-up time is 8.3 years (1.8-25.2 years). Survival was analyzed using the Kaplan-Meier estimate. Univariate Cox proportional-hazards models were used to identify the potential risk factors.

RESULTS

Only four patients (11.8%) experienced recurrence and all successfully underwent salvage therapy. One patient (2.97%) died due to suspected radiotherapy (RT)-related sarcoma in the scalp. The 2-, 3-, and 5-year DFS rates were 91.2%, 88.2%, and 79.4%, respectively; the 2-, 3-, and 5-year OS rates were 97.1%, 94.1%, and 82.4%, respectively. Focal RT showed low DFS in the Kaplan-Meier survival curves (P = .028) compared with non-focal RT (whole ventricle, whole brain, or cranial spinal area). In the univariate Cox proportional-hazards model, there was a significant difference in DFS between focal and non-focal RT (P = .03). There is no difference in DFS and OS between BG germinoma patients and non-BG germinoma patients.

CONCLUSIONS

We found an excellent DFS and OS in pediatric patients with BG germinoma treated with RT. Whole ventricle irradiation is recommended for good tumor control and low treatment-related toxicity. BG germinoma patients showed similar treatment results as germinoma patients in other common sites.