Pineal choriocarcinoma

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2]

Synonyms and keywords: Pineal embryonal cell carcinoma; Pineal gland tumor; Brain tumor

Overview

• Pineal choriocarcinoma is a relatively rare, malignant, highly vascular neoplasm and accounts for a small proportion of all intracranial germ cell tumors. It is an aggressive tumor and has a propensity to metastasise systemically. Pure pineal choriocarcinoma tumors secrete β-HCG.
• On microscopic histopathological analysis, pineal choriocarcinoma is characterized by presence of intimately related syncytiotrophoblasts and cytotrophoblasts without formation of definite placental type villi. Syncytiotrophoblasts are large multi-nucleated cells with eosinophilic cytoplasm. They often surround the cytotrophoblasts, reminiscent of their normal anatomical relationship in chorionic villi. Cytotrophoblasts are polyhedral, mononuclear cells with hyperchromatic nuclei and a clear or pale cytoplasm.
• Pineal choriocarcinoma accounts for 5% of all pineal masses.
• The peak age at diagnosis for pineal choriocarcinoma is 20-30 years.
• Common complications of pineal choriocarcinoma include:

• CSF metastasis
• Intraventricular hemorrhage
• Coma
• Systemic metastasis

• The clinical presentation of pineal choriocarcinoma is mainly from the obstructive hydrocephalus secondary to compression of the tectum of the midbrain and obstruction of the aqueduct. Symptoms of pineal choriocarcinoma include headache, vomiting, ptosis, and weakness.
• Compression of the superior colliculi can lead to a characteristic gaze palsy, known as Parinaud syndrome.
• Common physical examination findings of pineal choriocarcinoma include papilledema, signs of precocious puberty, restricted extraocular movements, sluggish pupillary light reflex, stiff neck, hemiparesis, and abducent nerve palsy.
• Laboratory findings consistent with the diagnosis of pineal choriocarcinoma include abnormal CSF analysis, demonstrating xanthochromia.
• Head CT scan and brain MRI may be helpful in the diagnosis of pineal choriocarcinoma.
• On head CT scan, pineal choriocarcinoma is characterized by a round, calcified, homogeneous, enhancing mass in the third ventricle associated with the dilation of the lateral and third ventricles and periventricular lucency.
• On brain MRI, pineal choriocarcinoma is characterized by hyperintensity on T1-weighted images and signal drop-out and blooming on T2* sequences.
• Biopsy is generally done to confirm the diagnosis of pineal choriocarcinoma.
• The mainstay of therapy for pineal choriocarcinoma is radiotherapy and/or chemotherapy. Sometimes, surgical resection may be done.

Management of Pineal Choriocarcinoma

Management Options of Penial Gland tumors
CSF diversion	The optimal surgical strategy to treat acute hydrocephalus in patients with pineal tumors is uncertain. CSF diversion (ventriculoperitoneal [VP] shunt or third ventriculostomy may be necessary in symptomatic patients, although debulking surgery may obviate the need for this procedure When CSF diversion is necessary, endoscopic third ventriculostomy can be carried out at the same time as the biopsy and is preferred over VP shunts, which can be complicated by infection, shunt malfunction, subdural hematoma, and rarely, tumor seeding
Surgical resection	Some series report long-term survival with surgery alone, even in patients with pineoblastomas. Indeed, for pineoblastomas, gross total surgical resection appears to correlate with improved survival. Patients with symptomatic recurrent pineocytomas should also be considered for surgical resection of the lesion
Radiation	Postoperative adjuvant RT is frequently (but not universally) recommended, and local control is dose-dependent. The incidence of leptomeningeal recurrence was significantly lower among patients receiving CSI compared with those who did not. The five-year survival rates were 86 and 49 percent for pineocytomas and non-pineocytoma PPTs, respectively. Adjuvant RT is not universally recommended after gross total resection of a pineocytoma
Stereotactic radiosurgery	Stereotactic radiosurgery (SRS) is emerging as a useful treatment alternative for pineocytomas, although experience is limited. The precise radiation fields that are defined by MRI or CT-computerized treatment planning minimize damage to the surrounding brain, and the risks of general anesthesia and craniotomy are avoided. SRS is increasingly being used to treat pineal region tumors, either as an additional therapy after conventional treatments or as a primary treatment. Due to the low rate of side effects, IRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant PPTs, IRS may be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.
Chemotherapy as part of multimodality therapy	The similarity of pineoblastomas to medulloblastomas in terms of their clinical behavior and tendency for leptomeningeal seeding has led to the use of similar chemotherapy regimens in patients with pineoblastoma as part of a multimodality approach. Chemotherapy has been used to delay radiation therapy in very young children, for whom the long-term neurocognitive and developmental side effects of craniospinal irradiation (CSI) are a major concern. The importance of radiation therapy as a component of the initial treatment of supratentorial primitive neuroectodermal tumors (PNETs) is also supported by the German HIT-SKK87 and HIT-SKK92 protocols, as well as the Canadian pediatric brain tumor protocol

References

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