Updated: 9/29/2019

Primary Brain Tumors

Review Topic
  • Presentation
    • Most common complaints are due to mass effects
      • e.g., seizures, dementia, focal lesions, headache
    • majority of adult primary tumors are supratentorial
    • majority of childhood primary tumors are infratentorial
  • Primary tumor characteristics
    • rarely undergo metastasis
    • usually poorly circumscribed
    • primary brain tumor frequency
      • meningioma > pituitary tumor > glioblastoma > nerve sheath tumor
    • risk factors
      • NF, cigarette smoking, Turcot's syndrome (colonic polyps and brain tumor)
  • Secondary tumor characteristics
    • 50% of adult brain tumors are due to metastases
    • well circumscribed
    • usually present at gray-white junction 
    • frequency of primary tumor causes
      • lung > breast > melanoma (skin) > kidney > GI
Adult peak-incidence tumors
  • Glioblastoma multiforme
    • type: grade IV astrocytoma
    • prognosis: grave (< 1 year life expectancy)
    • location: cerebral hemispheres
    • stain: GFAP
    • histologic appearance: "psuedopalisading" pleomorphic tumor cells  
      • border central areas of necrosis and hemorrhage
    • gross appearance: can cross corpus callosum (butterfly glioma)
    • note: may arise de novo or progress from a lower grade astrocytoma
  • Meningioma
    • prognosis: resectable
    • location: convexities of hemispheres , parasagittal region, olfactory groove
      • arises from arachnoid cells covering brain
    • histological appearance: spindle cells concentrically arrange in a whorled pattern 
      • psammoma bodies (laminated calcifications)
    • note: more common in women (due to estrogen receptors on tumor cells)
      • associated with neurofibromatosis
  • Schwannoma
    • prognosis: good, resectable
    • location: often localized to CN VIII → acoustic schwannoma
      • usually found at cerebrellopontine angle
      • can present with tinnitus, hearing loss
    • staining: S-100 positive 
    • histologic appearance: biphasic with hypercellular (Antoni A) and hypocellular (Antoni B) areas
    • note: bilateral schwannoma found in neurofibromatosis type 2
  • Oligodendroglioma
    • prognosis: good, slow growing
    • location: most often in frontal lobes
    • histologic appearance: chicken-wire capillary pattern with "fried egg" cells 
      • round nuclei with clear cytoplasm
    • gross appearance: often calcified in frontal lobe
Childhood peak-incidence tumors
  • Pilocytic (low-grade) astrocytoma
    • type: grade I astrocytoma
    • prognosis: benign
    • location: most often infratentorial
      • may be supratentorial (most commonly, craniopharyngioma)
    • stain: GFAP
    • histologic appearance: Rosenthal fibers  
      • eosinophilic corkscrew fibers 
    • gross appearance: cystic + solid, usually well-circumscribed
  • Medulloblastoma
    • most common malignant intracranial tumor of childhood
    • prognosis: poor, highly malignant
      • form of primitive neuroectodermal tumor (PNET)
    • location: cerebellum
      • can compress 4th ventricle → hydrocephalus
    • histologic appearance: rosettes with small blue cells  
    • gross appearance: solid
    • note: radiosensitive
  • Ependymoma
    • prognosis: poor
    • location: most commonly in 4th ventricle
      • can result in hydrocephalus
      • can also arise from cauda equina in adults
    • histologic appearance: characteristic perivascular pseudorosettes 
  • Hemangioblastoma (occurs typically in adults if no genetic predisposition as below)
    • location: cerebellar
    • histologic appearance: foamy cells and high vascularity
    • note: associated with von Hippel-Lindau syndrome when found with retinal angiomas
      • can produce EPO → secondary polycythemia
  • Craniopharyngioma 
    • prognosis: benign
    • location: near sella turcica 
      • can present with optic chiasm compression → bitemporal hemianopia
        • confused with pituitary adenoma
      • derived from remnants of Rathke's pouch 
    • gross appearance: calcification is common, tooth enamel-like
  • Germinoma
    • prognosis: good
    • location:  pineal gland and suprasellar region 
      • derived from nests of embryonic cells arrested during their migration in fetal development
      • Pineal region: Parinaud syndrome (30-40% of cases) compression of tectum causes: paralysis of upward gaze, loss of light perception and accomodation, nystagmus, failure of convergence
      • Suprasellar region: anterior hypopituitarism, precocious puberty, diabetes inspidius, visual disturbances
    • stain: AFP and b-HCG

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Questions (9)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2

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Topic COMMENTS (30)
Private Note