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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Sujit Routray, M.D. [2] Associate Editor(s)-in-Chief: Nabeel Ahmed, M.B.B.S
Synonyms and keywords: Pineal teratomas; Pineal teratoblastoma ; Pineal teratoid tumor; Pineal germ cell tumors; Pineal gland tumors; Brain tumor
Pineal teratoma is an uncommon extra-axial intracranial cancer, which can have varied components and thus a wide range of appearances.[1] The most frequent location of these tumors is pineal and suprasellar region. Clinical signs and symptoms depend on the localization of the tumor. Most commonly include signs of increased intracranial pressure, Parinaud's syndrome, bitemporal hemianopsia and signs of endocrine deficiency. Mature teratomas are benign, mature, well-differentiated cystic lesions; whereas immature teratomas are poorly differentiated lesions with solid components and malignant transformation. Symptoms of pineal teratoma include headache, vomiting, somnolence, and weakness. Compression of the superior colliculi by pineal teratoma can lead to a characteristic gaze palsy, known as Parinaud syndrome.
- Pineal teratoma may be classified into three sub-types:
- Mature
- Immature
- Mature with malignant transformation
- Mature teratomas are benign, mature, well-differentiated cystic lesions; whereas immature teratomas are poorly differentiated lesions with solid components and malignant transformation.[2]
- On other occasions, mature teratomas contain elements that undergo malignant transformation (most commonly squamous components).
- Fat
- Cystic spaces due to mucus production or other exocrine products
- Soft-tissue from any part of the body
- Calcification, including teeth
- On microscopic histopathological analysis, pineal teratoma is characterized by cells originating from at least two and usually all three embryonic layers (ectoderm, mesoderm, and endoderm). The histological subtype may not necessarily determine the biological behavior.[3]
Natural history, complications, and Prognosis[edit | edit source]
- Pineal teratomas may be associated with elevated levels of serum alpha fetoprotein (AFP) or serum carcinoembryonic antigen (CEA).[3]
- Pineal teratoma must be differentiated from pineal lipoma, pineal dermoid, and other pineal gland tumors.[4]
- Pineal teratoma is a rare disease that tends to affect the children and young adult population.[5]
- Common complications of pineal teratoma include:[5]
- Head CT scan and brain MRI may be helpful in the diagnosis of pineal teratoma.[6] Given their extremely variable histological components, CT/MRI imaging also tends to be heterogeneous, with tumors typically demonstrating a mixture of tissue densities and signal intensity. Fat, if present, is helpful in narrowing the differential.
- On head CT scan, pineal teratoma is characterized by a mass with fat and calcification, which is usually solid / "clump-like". It usually has cystic and solid components, contributing to an irregular outline. Solid components demonstrate variable enhancement on contrast administration.[6]
- On brain MRI, pineal teratoma is characterized by:[6]
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MRI component
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Findings
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T1
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- Hyperintense components due to fat and proteinaceous/lipid-rich fluid.
- Intermediate components of soft tissue.
- Hypointense components due to calcification and blood products.
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T1 with contrast
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- Solid soft tissue components show enhancement.
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T2
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- Mixed signal from differing components.
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- The mainstay of therapy for immature pineal teratoma is combined radiotherapy and chemotherapy.
- The residual or mature component is removed surgically.[7]
Management Options of Penial Gland Tumors
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CSF diversion
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Surgical resection
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- 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.
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Radiation
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- Postoperative adjuvant radiation therapy (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-pineocytomas, respectively.
- Adjuvant RT is not universally recommended after gross total resection of a pineocytoma.
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Stereotactic radiosurgery
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- 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, SRS may develop into an attractive alternative to microsurgery in de novo diagnosed pineocytomas. In malignant tumors, SRSmay be routinely applied in a multimodality treatment schedule supplementary to conventional irradiation.
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Chemotherapy as part of multimodality therapy
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- 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.
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- ↑ Intracranial teratomas. Dr Alexandra Stanislavsky and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/intracranial-teratoma. Accessed on December 10, 2015
- ↑ Teratoma. Dr Jeremy Jones and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/teratoma. Accessed on December 10, 2015
- ↑ 3.0 3.1 Pathology of extra-axial intracranial teratoma. Dr Alexandra Stanislavsky and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/intracranial-teratoma. Accessed on December 10, 2015
- ↑ Differential diagnosis of extra-axial intracranial teratomas. Dr Alexandra Stanislavsky and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/intracranial-teratoma. Accessed on December 10, 2015
- ↑ 5.0 5.1 5.2 Clinical presentation of extra-axial intracranial teratoma. Dr Alexandra Stanislavsky and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/intracranial-teratoma. Accessed on December 10, 2015
- ↑ 6.0 6.1 6.2 Radiographic features of intracranial teratoma. Dr Alexandra Stanislavsky and Frank Gaillard et al. Radiopaedia 2015. http://radiopaedia.org/articles/intracranial-teratoma. Accessed on December 10, 2015
- ↑ Friedman JA, Lynch JJ, Buckner JC, Scheithauer BW, Raffel C (2001). "Management of malignant pineal germ cell tumors with residual mature teratoma". Neurosurgery. 48 (3): 518–22, discussion 522-3. PMID 11270541.
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