Pineocytoma

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

Overview

Pineocytoma, also known as a pinealocytoma, is a benign, slowly growing pineal parenchymal tumor.

Pathophysiology

• On gross pathology, pineocytoma is characterized by solid, sometimes with focal areas of cystic change, well-circumscribed mass with or without hemorrhage.
• On microscopic histopathological analysis, pineocytoma is characterized by:

• Cytologically benign cells (uniform size of nuclei, regular nuclear membrane, light chromatin)
• Pineocytomatous/neurocytic rosette, which is an irregular circular/flower-like arrangement of cells with a large meshwork of fibers (neuropil) at the centre

• According to the WHO classification of tumors of the central nervous system, pineocytoma is classified into a WHO grade I tumor.

Gallery

• 

  _{Intermediate magnification micrograph of a pineocytoma. HPS stain.}

• 

  _{High magnification micrograph of a pineocytoma. HPS stain.}

• 

  _{Very high magnification micrograph of a pineocytoma. HPS stain.}

Epidemiology

• Pineocytoma is a rare disease that tends to affect all the age groups, most commonly in the second decade of life.
• Pineocytoma affects men and women equally.

Symptoms

• The clinical presentation is mainly from the obstructive hydrocephalus secondary to compression of the tectum of the midbrain and obstruction of the aqueduct.
• Symptoms of pineocytoma include:

• Headaches
• Nausea
• Vomiting
• Seizures
• Sleepiness
• Irritability
• Personality changes
• Double vision
• Trouble coordinating motor movements
• Difficulty walking
• Slowed growth

Physical Examination

• Compression of the superior colliculi can also lead to a characteristic gaze palsy, known as Parinaud syndrome.
• Common physical examination findings of pineocytoma include:

HEENT

• Bulging soft spots (fontanelles)
• Eyes that are constantly looking down (sunsetting sign)
• Parinaud syndrome

• Deficiency in upward-gaze
• Pupillary light-near dissociation (pupils respond to near stimuli but not light)
• Convergence-retraction nystagmus

Neurological

• Mental retardation

• Muscle spasms*Loss of bladder control

• Ataxia

References

Template:WikiDoc Sources