Neurosurgery notes/Tumours/Pineal tumours/Papillary tumour of the pineal region

Papillary tumour of the pineal region

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Pineal tumours

Definition

  • Essential:
    • Papillary growth pattern with epithelial-like cells AND
    • Characteristic immunohistochemical staining pattern (e.g. positivity for cytokeratins, SPDEF, CD56) AND
    • Pineal region location AND (for unresolved cases)
    • Confirmatory DNA methylation profiling

Numbers

  • Mean age 35 yrs
  • M:F ratio of 1.06:1
  • 181 case reported

Localisation

  • As above

Cell origin

  • Arise from specialised ependymocytes of the subcommissural organ located in the lining of the posterior commissure rather than from the pineal gland itself
    • PPTs

CNS WHO grading

  • Grade 2 or 3
    • Definitive histological grading not out yet

Histopathology

Macroscopy

  • Well circumscribed
  • They are grossly indistinguishable from pineocytomas

Microscopy

  • Has both epithelial and papillary features
  • Variable morphology ranging from solid to predominantly papillary, reminiscent of ependymomas (true rosettes and tubes).
 
Fig. 7.20 Papillary tumour of the pineal region. A The vascular axes of neoplastic papillae often harbour multiple B In some tumours, bizarre pleomorphic cells are observed; this nuclear atypia is more dystrophic in nature than related vascularized core, leading to an apparent clear perivascular space. Note the e)densive necrosis. capillaries, resulting in a pseudoangiomatous appearance. to anaplasia. C Neoplastic cells detached from the papillary
(A) The vascular axes of neoplastic papillae often harbour multiple capillaries, resulting in a pseudoangiomatous appearance. (B) In some tumours, bizarre pleomorphic cells are observed; this nuclear atypia is more dystrophic in nature than related to anaplasia. (C) Neoplastic cells detached from the papillary vascularized core, leading to an apparent clear perivascular space. Note the extensive necrosis.

Immunophenotype

  • Cytokeratins (AE1/3, CAM5.2, KL1, CK18): positive in papillary structure
  • S100: positive
  • Vimentin: positive
  • Tansthyretin: positive
  • Neurone-specific enolase: positive
  • MAP2: positive
  • GFAP: variable

Genetic profile

  • DNA methylation profiles differentiating papillary tumours of the pineal region from ependymomas
  • No expression of the V600Emutant BRAF protein

Clinical presentation

  • Compression of pineal s(x)
    • Cerebral aqueduct:
      • Obstruction HCP
        • Papilledema
        • H/A
        • Ataxia
        • Impaired vision
        • N/V
    • Brain stem
      • Tectal plate compression: Parinaud syndrome
        • Loss of upward gaze
    • Cerebellum
      • Dizziness
      • Tremor
  • Endocrine
    • Diabetes insipidus
      • Present with DI because it infiltrates the floor of 3rd ventricle affecting the pituitary
    • Precocious puberty
  • Acute clinical presentation can be due to tumour apoplectic

Radiological

  • MRI
    • Papillary tumours of the pineal region are often indistinguishable from pineocytomas.
      • Images
      A close-up of an x-ray AI-generated content may be incorrect.
      T1
      A close-up of a mri scan AI-generated content may be incorrect.
      T1+C
      A close-up of an x-ray AI-generated content may be incorrect.
      T1+C
       
      A close-up of an x-ray AI-generated content may be incorrect.
      T2
       

Prognosis

  • Overall survival is 73% at 5 years and 71.6% at 10 years.
  • Progression free survival is 27%
  • Tendency for recurrence and need for repeated surgery
    • 57% local recurrence
  • Screening of the entire neural axis is required as CSF dissemination has been reported in up to 7% of cases
  • Good prognostic value
    • Young patients
    • Gross total resection
  • Poor prognostic value
    • High mitotic rate
      • >3 mitosis per 10 high power fields: 52 months vs 68 months
      • Ki67>10% vs <10% → median progression free survival time of 29 month vs67 months