Pineal Germinoma

Nandakumar Srinivasan, MD; Aneesh Pakala, MD; Chandana Mukkamalla, MD; Alok Oswal, MD

Disclosures

South Med J. 2010;103(10):1031-1037. 

In This Article

Follow-up

Initial follow-up exams after completion of chemotherapy must be performed at short intervals, including frequent evaluation of tumor markers.[1] Treatment response is evaluated by follow-up MRI scans every 6 months for 3 year after diagnosis and then at 1-year intervals. Clinical remission is defined by the normalization of tumor markers and the absence of residual tumor. Even then, total removal of the germ cell tumor does not mean complete cure as macroscopic tumor removal does not automatically mean cytological absence of disease. The measurement of serum tumor markers, such as HCG and AFP, cannot accurately detect the recurrence of the tumor. Radiotherapy may be required to prevent the recurrence of a tumor marker producing germ cell tumor even though histological examination does not detect immature cells in the surgically removed tissue.[1]

The recurrence of tumors is rare and related to sampling error or negative biopsy which leads to inadequate treatment.[20] Wenger et al reported late recurrence of a pineal germinoma that occurred after successful initial treatment.[20] It is rare for another type of GCT to develop after successful eradication of a pineal germinoma if whole brain irradiation is performed. If this phenomenon does occur, then it is due to the primordial germ cells that stray into other sites in the brain. Tsunoda et al suggest periodic AFP and HCG to detect these GCTs in patients with intracranial germinomas who did not receive whole brain irradiation.[44]

The major recurrence sites for germinomas are the suprasellar compartment and the ventricular walls. The rate of recurrence after appropriate radiation therapy is around 10–17%, and it usually occurs within the first 2 years of the eradication of the initial tumor.[20] Recurrence after 5 years is extremely rare, but isolated case reports have identified patients with recurrences ranging from 9–23 years after successful radiation therapy.[20]

Wenger et al suggest that the diagnostic and treatment algorithm of primary or recurrent pineal germinomas should be identical and inclusive of stereotactic biopsy of the mass and that recurrent lesions should be treated with radiation and platinum-based adjuvant chemotherapy.[20] Isolated chemotherapy for recurrent lesions has been tried with limited success. The reason for the limited efficacy of chemotherapy against recurrent lesions is thought to be due to radiation- induced fibrotic changes around the vasculature that prevents the adequate penetration of the chemotherapeutic agent into the blood-brain barrier.

Ono et al have described four patterns of recurrence in germinoma patients.[45] Type I: intracranial recurrence is caused by inadequate initial irradiation field and is treated by total craniospinal irradiation. Type II: recurrence is characterized by benign teratoma caused by late growth of the teratoma component and is treated by surgery alone. Type III: local recurrence is characterized by HCG or AFP, producing tumors of extra-embryonic origin. According to the authors, this pattern of recurrence should be treated by chemotherapy or radiosurgery. Type IV: recurrence is extracranial metastasis without the evidence of intracranial recurrence. The authors suggested that this group of patients could be treated with chemotherapy alone. The authors also recommended chemotherapy in treating germinomas that have a VP shunt because of the risk of extraneural metastasis in the future.[45]

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