Pineoblastoma

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

Synonyms and keywords: Pineoblastomas; Pinealoblastoma; Pinealoblastomas; PB; Pineal parenchymal tumor; Pineal gland tumor; Brain tumor

Overview

Pineoblastoma is a rare, malignant pineal parenchymal tumor. It is a supratentorial midline primitive neuroectodermal tumor. It is considered as a WHO grade IV tumor according to the WHO classification of tumors of the central nervous system.

Pathophysiology

Pathogenesis

Pineoblastoma originates from the neuroectodermal cells. It is the least differentiated pineal gland tumors, with pineocytoma and pineal parenchymal tumour with intermediate differentiation representing better differentiated tumors along the same spectrum.

Associated Conditions

Pineoblastoma may occur in patients with hereditary uni- or bilateral retinoblastoma. When retinoblastoma patients present with pineoblastoma, this is characterized as "trilateral retinoblastoma".

Gross Pathology

On gross pathology, pineoblastoma is characterized by solid, large poorly defined masses.

Gallery

• 

  _{An autopsy specimen showing a rather large pineal tumor. It was a pineoblastoma composed of highly cellular sheets of anaplastic cells with irregular hyperchromatic nuclei and brisk mitotic activity – resembling medulloblastoma and retinoblastoma.}

• File:===Microscopic Pathology===
• File:*Hypercellular
• File:*Tightly packed small round blue cells (high nuclear to cytoplasmic ratio)
• File:*Homer-wright & Flexner-Winterstein rosettes
• File:*Fleurettes
• File:===Immunohistochemistry===
• File:==Differentiating Pineoblastoma from other Diseases==
• File:*Pineal germinoma
• File:*Pineal embryonal carcinoma
• File:*Pineal choriocarcinoma
• File:*Pineal yolk sac carcinoma (endodermal sinus tumor)
• File:*Pineal teratoma
• File:==Epidemiology and Demographics==
• File:===Prevalence===
• File:===Age===
• File:===Gender===
• File:==Natural History, Complications and Prognosis==
• File:===Natural History===
• File:===Complications===
• File:*Local recurrence
• File:===Prognosis===
• File:==History and Symptoms==
• File:===History===
• File:When evaluating a patient for pineoblastoma, you should take a detailed history of the presenting symptom (onset, duration, and progression), other associated symptoms, and a thorough family and past medical history review.
• File:===Symptoms===
• File:==Physical Examination==
• File:===HEENT===
• File:*Deficiency in upward-gaze
• File:*Pupillary light-near dissociation (pupils respond to near stimuli but not light)
• File:===Neurological===
• File:==CT==
• File:*Head CT scan may be diagnostic of pineoblastoma.
• File:===Gallery===
• 

  _{Pineal calcification: exploded calcification of tumors of pineal cell origin, whereas engulfed calcification by germinomas.}

• 

  _{Single head CT image demonstrates a soft tissue mass in the region of the pineal gland with eccentric calcification (anterior) and evidence of hydrocephalus.}

MRI

• Brain MRI may be diagnostic of pineoblastoma.
• Features on MRI suggestive of pineoblastoma include:

MRI component	Findings
T1	Isointense to hypointense to adjacent brain
T2	Isointense to adjacent brain Areas of cyst formation or necrosis may be present
T1 with gadolinium contrast	Vivid heterogenous enhancement
Diffuse weighted imaging/Apparent diffusion coefficient	Restricted diffusion due to dense cellular packing ADC values are typically 400-800 mm2/s

Treatment

The predominant therapy for pineoblastoma is surgical resection. Adjunctive chemotherapy and radiation may be required.

References

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