Tumors

Denita Ryan and Estelle Doris

Keywords: lymphoma, meningioma, metastatic tumors, nerve sheath tumors, pituitary tumors, primary tumors

7.1 Tumors of the Central Nervous System

The American Brain Tumor Association estimates that, in 2017, roughly 80,000 patients in the United States will be diagnosed with new tumors of the central nervous system (CNS) and there will be roughly 10 times as many people living with a CNS tumor. Although not all tumors are malignant, many are. In 2017, approximately 17,000 people will die from brain or spinal cord malignancies (Box 7.1 Tumor Statistics).

7.1.1 Classification of Tumors

Benign

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  Benign tumors are composed of microscopic cells that are well differentiated and not aggressive

  
  
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  Complete surgical resection may be curative

  
  
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  Histologically benign tumors located in surgically inaccessible and eloquent areas of the brain may cause neurologic symptoms and can result in death if allowed to grow and left untreated (Video 7.1)

  
  
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  May become malignant if left untreated

Malignant

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  Malignant tumors have poorly differentiated cells and may be both aggressive and invasive (▶ Table 7.1)

  
  
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  Surgical resection may remove the tumor or reduce its size, but resection may not be curative because of the aggressive nature of these cells

  
  
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  Prognosis is usually poor but depends on many factors, such as extent of resection

  
  
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  The most commonly used grading scale for tumors is from the World Health Organization (WHO).

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Table 7.1 Malignant brain tumors: what to watch for

  Complication	Indication	Nursing action	Rationale
  Decreased LOC/neurologic function	Cerebral edema Hemorrhage	Perform accurate and thorough neurologic assessment	An accurate initial assessment will determine the patient’s neurologic status and provide a baseline for future assessments
  		Compare most recent assessment to baseline assessment	Proper documentation will allow caretakers to detect improvement or decline in the patient’s neurologic status
  		Protect patient’s airway (e.g., from aspiration), such as by keeping his head elevated	A patient with decreased LOC is at risk for respiratory failure and must have the airway protected if this cannot be done independently
  		Note any sedating medications	Use of sedating drugs may be the reason for a change in LOC
  		If patient is on steroids, determine the present dose and whether dosage has recently been changed	A decrease in dose of dexamethasone, especially an abrupt decrease, could cause increased vasogenic edema and decreased neurologic function
  		Report changes in LOC immediately	Patient could be at risk for herniation
  Seizure	If new, seizure may indicate hemorrhage or edema	Report seizure if it is a new occurrence for the patient Ensure patient’s safety	Many patients with malignant tumors have seizures
  Respiratory distress	PE	Perform respiratory assessment, including oxygen saturation level, arterial blood gases, pulmonary function tests, and auscultation Check other vital signs, including blood pressure and heart rate Prevent PE with Lovenox, sequential compression devices, and, most importantly, ambulation	Patients with malignant tumors may be at risk for atelectasis (i.e., incomplete expansion of the lung) and pneumonia, but PE is a life-threatening risk for all patients with malignant tumors
  Abbreviations: LOC, level of consciousness; PE, pulmonary embolism.

Primary

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  Primary tumors originate in the brain or elsewhere in the CNS

  
  
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  Rarely travel to other areas of the body

Metastatic

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  Metastatic tumors originate in other areas of the body

  
  
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  Travel to organs such as the brain and spinal cord

7.2 Primary Tumors

7.2.1 Tumors of Neuroepithelial Tissue

Glial Tumors

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  These tumors arise from glial cells, which are the nourishing or supportive cells of the brain; they are referred to as gliomas

  
  
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  There are several types of glial cells, including astrocytes, oligodendrocytes, and ependymal cells

  
  
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  Different types of glial tumors are named for the type of cells from which they originate; some gliomas exist in pure form, while others have mixed cell types

  
  
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  Graded according to the degree of malignancy (▶ Table 7.2).

  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  Table 7.2 Classification of tumors: gliomas

  Tumor type	Average age at onset	Clinical manifestation	Treatment	Prognosis
  WHO grade I astrocytoma	Mostly in children	Varies by location and size	Observation Surgery	Excellent
  WHO grade II low-grade astrocytoma	May occur at any age; in adults, average age is 30 y	Varies by location and size	Surgery Radiotherapy Chemotherapy	Depends on size, extent of resection, patient’s age, and recurrence
  WHO grade III anaplastic astrocytoma	Between 35 and 50 y	Varies by location and size	Surgery Radiotherapy Chemotherapy	Mean survival of 22 mo with treatment (shorter for patients aged 40 y and older, and longer for patients younger than 40 y)
  WHO grade IV GBM	May occur at any age, but most commonly the onset occurs in the 50s; the incidence of this type of tumor declines thereafter	Varies by location and size Hemorrhage into tumor bed is not uncommon, but neurologic decline is more prevalent	Surgery Radiotherapy Chemotherapy	Mean survival of 14 mo with treatment (shorter for patients aged 40 y and older, and longer for patients younger than 40 y) Important prognostic factors include extent of resection, tumor size, multifocality, and whether the tumor crosses the midline
  Oligodendroglioma	Between 40 and 60 y	Frequent seizures Symptoms vary by the lesion’s size and location Patients may present with frontal lobe anomalies given these tumors commonly occur in the frontal lobe	Surgery Radiotherapy for higher grades Chemotherapy for higher grades	5 to more than 10 y with treatment Deletion of chromosome 1p19q is a favorable prognostic indicator
  Ependymoma	Can occur at all ages, but 60% of people diagnosed with ependymomas are children	Signs and symptoms of increased ICP Hydrocephalus	Surgery Radiotherapy or chemotherapy for recurrence Shunt may be required	7 to more than 8 y with surgical treatment Poor prognostic indicators include subtotal resection, recurrence, and CSF dissemination (seeding)
  Abbreviations: CSF, cerebrospinal fluid; GBM, glioblastoma multiforme; ICP, intracranial pressure; WHO, World Health Organization.

Astrocytomas

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  Arise from astrocyte cells

  
  
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  Vary in degree of differentiation and malignancy

  
  
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  Graded according to degree of malignancy

  
  
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  Do not spread outside the CNS (▶ Fig. 7.1)

Grades of Astrocytoma

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  Pilocytic astrocytoma (WHO grade I)

  
  
  
  
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    Slow-growing, benign

    
    
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    Many different types of grade I tumors exist, but pilocytic is the most common

    
    
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    Mostly occur in pediatric patients

  
  
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  Low-grade astrocytoma (WHO grade II)

  
  
  
  
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    Low-grade tumor, but not benign

    
    
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    Heterogeneous

    
    
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    Treatment depends on the age of the patient and the extent of resection possible

  
  
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  Anaplastic astrocytoma (WHO grade III)

  
  
  
  
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    Malignant

    
    
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    Mean age at onset is 35 to 55 years.

    
    
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    May progress to higher grade (Box 7.2 Prognostic Factors for Malignant Gliomas)

  
  
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  Glioblastoma multiforme (GBM) (WHO grade IV)

  
  
  
  
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    Highly malignant and aggressive

    
    
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    Associated with vasogenic edema

    
    
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    Necrosis present within tumor

    
    
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    Complete resection impossible because of microscopic proliferation

    
    
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    Poor prognosis (▶ Fig. 7.2).

Oligodendrogliomas

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  Arise from oligodendrocyte cells

  
  
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  Categorized as grade I, II, or III by degree of malignancy

Ependymomas

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  Arise from ependymal cells, which line the ventricles and spinal cord (▶ Fig. 7.3)

  
  
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  Account for approximately 1.7% of all primary brain tumors

  
  
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  Categorized as grade I, II, or III by degree of malignancy.

  
  
  
  

  

  
  

  Fig. 7.3 Ependymoma.

Gangliogliomas

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  Variant of glial neoplasms, but also contain neuronal tissue

  
  
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  Usually benign but may grow

  
  
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  Account for fewer than 1% of all glial neoplasms

  
  
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  Occur in patients of all ages

  
  
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  Associated with seizures

Pineal Tumors

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  Benign (▶ Fig. 7.4)

  
  
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  May obstruct the aqueduct and third ventricle, causing hydrocephalus

  
  
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  Headaches and visual disturbances are common symptoms

  
  
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  Excellent prognosis with total resection.

  
  
  
  

  

  
  

  Fig. 7.4 Pineal tumor.

Choroid Plexus Papillomas

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  Originate in the choroid plexus

  
  
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  Can be found in any ventricle but most commonly occur in the fourth ventricle

  
  
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  Hydrocephalus with increased intracranial pressure (ICP) is the most common presentation

  
  
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  Occur in patients of all ages

  
  
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  May be low-grade or anaplastic

7.2.2 Tumors of the Meninges

Meningiomas

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  Arise from the meninges (▶ Fig. 7.5)

  
  
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  Seldom invade the brain tissue

  
  
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  Categorized as grade I, II, or III, depending on degree of malignancy (▶ Table 7.3)

  
  
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  Grow very slowly

  
  
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  Rarely malignant, but malignant meningiomas can be aggressive

  
  
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  May be located in eloquent areas of the brain, causing neurologic deficits

  
  
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  Histologically benign meningiomas may have features that can result in neurologic deficit (Box 7.3 Benign Tumors and Box 7.4 When Benign Is Not: Meningiomas)

7.2.3 Tumors of the Sella

Sellar tumors are rarely malignant. There are several different types (▶ Table 7.4).

Pituitary Adenomas

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  These tumors occur most frequently in the anterior lobe of the pituitary gland (▶ Fig. 7.6)

  
  
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  Mostly benign

  
  
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  Classified by whether they are nonfunctioning (do not secrete hormones) or functioning (hormone-secreting). Functioning pituitary adenomas can be further classified by the type of hormone secreted

  
  
  
  
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    Prolactin. Increased levels may result in

    
    
    
    
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      Amenorrhea

      
      
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      Galactorrhea

    
    
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    Adrenocorticotropic hormone. Increased levels may result in

    
    
    
    
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      Cushing’s disease

    
    
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    Growth hormone. Increased levels may result in

    
    
    
    
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      Acromegaly

    
    
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    Thyroid-stimulating hormone. Increased levels may result in

    
    
    
    
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      Increased heart rate

      
      
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      Anxiety

      
      
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      Weight loss

  
  
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  Pituitary adenomas are also classified by size

  
  
  
  
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    Microadenoma: <10 mm

    
    
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    Macroadenoma: ≥10 mm

    
    
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    Giant ≥40 mm

  
  
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  Symptoms may be caused by hormone secretion or triggered by the pressure that a tumor exerts on the tissues that surround it; see Table 1.1 in Chapter 1

  
  
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  Visual loss may be the first symptom

  
  
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  May cause pituitary apoplexy (Box 7.5 Pituitary Apoplexy)

  
  
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  Treatment may be medical or surgical (▶ Table 7.5)

  
  
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  Prognosis is usually excellent

Box 7.5 Pituitary Apoplexy

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  Pituitary apoplexy results from hemorrhage or infarction of a pituitary adenoma; it may occur in normal pituitary gland or in other areas of the sella (e.g., a Rathke’s cleft cyst)

  
  
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  Clinical manifestations include rapid neurologic decline, especially visual loss, headache, and decreased level of consciousness

  
  
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  Pituitary apoplexy is best treated by rapid assessment and management of hormonal anomalies, including administration of steroids; surgical decompression may be warranted to preserve visual acuity and treat possible hydrocephalus

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