Pineal embryonal carcinoma

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 embryonal carcinoma is a relatively rare malignant 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. A component of embryonal carcinoma is often found in mixed germ-cell tumours, in which case it is usually the most aggressive component, and dictates prognosis. Pure pineal embryonal carcinoma tumors do not secrete β-HCG or AFP.
• On microscopic histopathological analysis, pineal embryonal carcinoma is characterized by:
  • Poorly differentiated, pleomorphic cells in cords, sheets, or papillary formation
  • Indistinct cell borders
  • Nucleoli - key feature
  • Vesicular nuclei (clear, empty appearing nuclei) - key feature
  • Necrosis - common
  • Mitoses - common
  • Variable architecture:
    • Solid (predominant in ~55% of cases)
    • Glandular (predominant in ~17% of cases)
    • Papillary (predominant in ~11% of cases)
    • Nested
    • Micropapillary
    • Anastomosing glandular
    • Sieve-like glandular
    • Pseudopapillary
    • Blastocyst-like
    • Embryoid bodies - ball of cells in surrounded by empty space on three sides
• Pineal embryonal carcinoma is demonstrated by positivity to tumor markers such as:

• OCT4
• CD30

• Pineal embryonal carcinoma must be differentiated from:

• Pineocytoma
• Pineal parenchymal tumor with intermediate differentiation
• Papillary tumor of the pineal region
• Pineoblastoma
• Pineal germinoma
• Pineal choriocarcinoma
• Pineal yolk sac carcinoma (endodermal sinus tumor)
• Pineal teratoma
• Pineal cyst
• Astrocytoma of the pineal gland
• Meningioma near pineal gland
• Pineal metastasis
• Cavernoma in pineal region
• Aneurysm in pineal region
• If left untreated, patients with pineal embryonal carcinoma may progress to develop seizures, obstructive hydrocephalus, and CSF metastasis.

• Common complications of pineal embryonal carcinoma include:

• Obstructive hydrocephalus
• Leptomeningeal spread
• Systemic metastasis

• The clinical presentation of pineal embryonal carcinoma is mainly from the obstructive hydrocephalus secondary to compression of the tectum of the midbrain and obstruction of the aqueduct. Symptoms of pineal embryonal carcinoma include headaches, nausea, vomiting, seizures, hearing loss, sleepiness, and double vision.
• Compression of the superior colliculi can lead to a characteristic gaze palsy, known as Parinaud syndrome.
• Head CT and brain MRI may be diagnostic of pineal embryonal carcinoma.
• Biopsy is generally done to confirm the diagnosis of pineal embryonal carcinoma.

Treatment

• The mainstay of therapy for pineal embryonal carcinoma is radiotherapy and/or chemotherapy. Sometimes, surgical resection may be done.

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

Template:WikiDoc Sources