Pediatric Oncologic Emergencies

Thoracic Emergencies

Superior Vena Cava Syndrome and Superior Mediastinum Syndrome

Superior Vena Cava Syndrome (SVCS)

SVCS refers to the obstruction of the superior vena cava due to compression or thrombosis, typically caused by rapidly growing anterior and superior mediastinal masses. SVCS is more common in rapidly growing masses, as slowly growing masses may allow the development of collateral circulation, mitigating symptoms.

Superior Mediastinal Syndrome (SMS)

SMS is a combination of SVCS with tracheal compression. In pediatrics, SVCS and SMS often present overlapping clinical features.

Etiology

Intrinsic causes: Vascular thrombosis, such as post-catheter insertion.

Extrinsic causes: Malignant anterior mediastinal tumors producing extrinsic compression, including:

• Hodgkin's lymphoma
• Non-Hodgkin's disease
• Teratomas and other germ cell tumors
• Thyroid cancers
• Thymoma
• T-cell Acute Lymphoblastic Leukemia (ALL)

Also read: Tumor Lysis Syndrome

Clinical Features

Superior Vena Cava Syndrome (SVCS)

Swelling, plethora, and cyanosis of the face, neck, and upper limbs. Conjunctival suffusion. Engorged collateral veins, Horner's syndrome. Altered sensorium (mental status changes).

Superior Mediastinum Syndrome (SMS)

Symptoms of SVCS plus respiratory features: cough, dyspnea, orthopnea, stridor or wheezing, and hoarseness of voice. Dysphagia due to esophageal compression. Chest pain and syncope.

Investigations

• Chest X-ray and CT scan (chest CT optional).
• Blood tests: CBC, LDH, uric acid, AFP, and beta HCG.
• ECG if the chest X-ray is normal.
• Intubation may be required before invasive diagnostic procedures in SMS, as airway compromise can develop quickly.

Also read: Hepatoblastoma in Children

Management

Steroids

Considered first-line treatment, even though they can cause diagnostic confusion. Either prednisolone (2 mg/kg/day) or methylprednisolone (1.6 mg/kg/day) can be employed. Steroids help reduce airway edema and circulating tumor cells in leukemia.

Radiotherapy

Alternative to steroids. Once tumor mass has shrunk, patients can be biopsied and extubated. Specific chemotherapy should follow.

Thrombolysis

For patients with symptomatic venous thrombosis causing SVCs and SMS, start thrombolysis using either UFH or LMWH. Rule out hemorrhage or hemorrhagic tendency. Unfractionated Heparin (UFH): 75 U/kg bolus, followed by 18 U/kg/hour infusion (for children). Target aPTT 60-85 seconds or anti-Xa levels of 0.3-0.7 U/ml. Low molecular weight Heparin (LMWH) (e.g., enoxaparin): 1 mg/kg every 12 hours. Titrate to a target anti-Xa level of 0.5–1 U/ml. Patients on UFH should be transitioned to LMWH for outpatient management.

Abdominal Emergencies

The most common GIT problem in oncology patients: esophagitis (not emergency). Oncological emergencies associated with neutropenia

• Typhlitis
• Perirectal abscess

Hemorrhagic pancreatitis: associated with L-asparaginase Rx

Massive hepatomegaly in infants: suspect neuroblastoma stage IVS

Also read: Rhabdomyosarcoma in Children

Typhlitis (Neutropenic Enterocolitis)

A necrotizing colitis, localized to the caecum seen in neutropenic patients, is commonly seen in leukemia and sometimes solid tumors. Pathogens include Pseudomonas, E. coli, Staph aureus, and Streptococcus species.

Pathophysiology

Mucosal injury with neutropenia predisposes to bacterial invasion and inflammation, which can progress rapidly to full-thickness inflammation, Perforation, Peritonitis and Shock

Common Presentation

Patient with neutropenia present with

• A right lower quadrant pain-Hallmark
• There may or may not be right lower abdominal mass.
• Febrile.
• Bowel sounds may be absent on auscultation.
• Patients may present with features of perforation and septic shock.

Imaging in Typhlitis

X - ray: pneumatosis intestinalis, bowel wall thickening, or pneumoperitoneum. Pneumoperitoneum will indicate perforation;

Perforation will appear in the form of air under the diaphragm.

Ultrasonography: screening investigation: thickened bowel wall in the caecal region.

CT scan: investigation of choice and the most accurate investigation in typhlitis.

• Diffuse thickening of the caecal wall.
• Contrast CT is preferred over non-contrast CT scans.

Barium enema: severe mucosal irregularity, rigidity, loss of haustral markings, and occasional fistula formation.

CT scan: thickened cecum, hypodensity, and definite enterocolitis.

Showing a right-sided caecal enlargement enterocolitis.

Also read: Langerhans Cell Histiocytosis in Children

Medical management

NPO, start NG tube suction.

IV fluids: present with shock - bolus IV fluids; present with no shock-maintenance IV fluids.

Broad-spectrum IV antibiotics: gram-positive bacteria, gram-negative bacteria, and anaerobes, and pseudomonal coverage is also recommended.

• Ceftriaxone with Amikacin and Metronidazole.
• Cefoperazone with Amikacin and Metronidazole.
• Vancomycin with Meropenem.
• Meropenem has both coverage of anaerobes and some pseudomonal activity.
• Vasopressors and transfusions as needed: G-CSF transfusions can be considered.

Surgical Indications

Persistent GI bleeding, Perforation, and bowel infarction with clinical deterioration

Other Abdominal Emergencies in Cancer

Perirectal abscess

Can occur in patients on chemotherapy and radiotherapy, especially if neutropenic. Only prolonged neutropenia leads to a perirectal abscess. It is usually a polymicrobial infection. Mix of gram-positive-negative and anaerobic bacteria. Most patients present with anorectal pain, tenderness, and painful defecation. If the patient is neutropenic, no PUS discharge. And instead, there will be brawny enema and dense cellulitis. Treatment: IV antibiotics broad spectrum, IV fluids, G-CSF to increase the neutrophil count, and a Sitz bath provide symptomatic relief. Surgical I&D in Fluctuant areas or draining Fistulas

Common Causes of Abdominal Pain in Childhood Malignancy

• Typhilitis
• Perirectal abscess
• Bowel obstruction
• Constipation or Ileus.
• Hepatic enlargement
• Pancreatitis
• Veno-occlusive Disease

Also read: Rare Cancers in Children

Neurological Emergencies

There are two important neurological emergencies:

• Spinal cord compression
• Raised intracranial pressure

Spinal Cord Compression

Seen in about 3-5% percent of pediatric malignancies. Compression may happen in epidural and subarachnoid space, or parenchyma.

Etiology

Sarcomas comprise about 50% of all tumors in children, which cause spinal cord compression. Among them, most cases are due to either Ewing sarcoma or rhabdomyosarcoma.

• Neuroblastoma
• Germ cell tumors
• Leukemias
• Lymphomas

Drop metastasis of the CNS tumors. Drop metastasis is mostly because of medulloblastoma.

Mechanism of spread to spinal cord

The first mechanism is the direct extension of the tumor to the spinal cord. The second mechanism is metastatic spread to the vertebra with secondary cord compression. commonly seen in

Neuroblastoma. The third mechanism is spread to the epidural space via infiltration of the vertebral foramina. The fourth mechanism is subarachnoid spread down the code from the primary CNS tumor. Seen in medulloblastoma.

Also read: What's New In Paediatric Oncology

Clinical Features

Back pain and localized tenderness are seen in about 80% of individuals. According to the compressed spinal cord level, the features may vary for spinal cord involvement. For children with spinal cord involvement above the T10 level.

• Increased DTRs
• Symmetric weakness
• Sensory level present
• Positive Babinski

In the case of conus medullaris involvement that is T10 to L2,

• Symmetric weakness
• Increased knee reflexes
• Decreased ankle reflexes
• Babinski +/-

Cauda equina involvement, occur below L2

• Asymmetric weakness
• Loss of deep tendon reflexes
• Sensory deficit
• Babinski Negative

Investigations

X-ray spine: Detects vertebral metastasis but misses out on epidural disease in about 50% of these cases. X-ray spine—initial test. MRI: MRI is the investigation of choice.

Initially, a plain MRI film is taken, then it is followed by a gadolinium contrast used to take the contrast to enhance the picture. LP Myelography: Now, it is obsolete. CSF analysis: CSF analysis is useful for subarachnoid disease but does not help in localizing epidural disease.

Also read: Principles Of Therapy In Children

Management 

Steroids

Steroids are the initial drug to be used. Start the patient on dexamethasone. Dexamethasone decreases local edema, followed by MRI in any acute presentation.

Individualized Management

Specific chemotherapy for leukemia, lymphoma, or neuroblastoma. If radiosensitive tumor: Give radiotherapy, including the therapy for tumor mass with one vertebra above and below the lesion. Surgical emergency: laminotomy or laminectomy. may be needed for rapid decompression, especially in sarcomas or epidural masses, which are less responsive to radiotherapy.

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