Perirectal Abscess/Cholecystitis/Veno-Occlusive Disease

In pediatric oncology, certain emergencies require immediate attention due to their complex nature and potential for rapid deterioration. Perirectal abscess, a painful and potentially serious infection near the rectum, poses a significant risk of sepsis. Cholecystitis, or inflammation of the gallbladder, can occur due to various factors, including complications from cancer therapy. Veno-occlusive disease (VOD), a condition affecting the liver’s small veins, often emerges as a serious side effect of chemotherapy or stem cell transplantation. Early recognition and prompt management of these conditions are crucial to prevent severe outcomes in pediatric oncology patients.

Perirectal abscess

• Perirectal abscesses occur predominantly in patients diagnosed with Acute Myeloid Leukaemia (AML).
• These patients often experience anorectal pain, tenderness, and discomfort. The primary physical manifestation might be a tender, firm swelling indicative of woody edema accompanied by severe cellulitis.
• The infection typically involves a mix of pathogens including Staphylococcus, Streptococcus, Escherichia coli, Pseudomonas, and faecal anaerobes.

Management

• Treatment involves administering broad-spectrum antibiotics, including coverage for anaerobic bacteria.
• Recommendations include sitz baths to alleviate discomfort.
• Lesions that are well-defined and worsening necessitate surgical intervention through incision and drainage.

Cholecystitis & Biliary obstruction

• Cholecystitis, the inflammation of the gallbladder, can manifest in two forms: calculous, involving gallstones, or acalculous, which does not involve gallstones and is primarily observed in septic, nutritionally depleted children. Symptoms typically include pain in the right upper quadrant of the abdomen or jaundice. Biliary obstruction, although rare, can be caused by primary tumors such as lymphoma, Rhabdomyosarcoma (RMS), or Neuroblastoma (NB).
• Diagnostic Imaging: Ultrasound (US) and Computed Tomography (CT) scans are crucial for distinguishing between calculous and acalculous cholecystitis, as well as identifying biliary obstruction.

Management

• Hydration and Antibiotics: Initial management requires adequate hydration and the administration of broad-spectrum antibiotics, including those effective against anaerobes.
• Nasogastric Decompression: This technique can alleviate symptoms and manage the condition by reducing intragastric pressure.
• Endoscopic-Cutaneous Decompression: For cases requiring further intervention, a combined endoscopic and cutaneous approach to decompression has been found to be effective.
• Stent Placement: In situations where palliation is the goal, especially in the context of obstructive conditions, the placement of a stent can offer symptom relief for up to six months.
• These management strategies aim to address the immediate symptoms and underlying causes of cholecystitis and biliary obstruction, providing both relief and, in some cases, a palliative approach to care.

Veno-occlusive disease

VOD can arise following cytoreductive therapy administered in preparation for bone marrow transplantation (BMT). Less severe instances of VOD have been linked to treatments involving vincristine or actinomycin D, potentially combined with cyclophosphamide. Notably, thioguanine is strongly associated with VOD; research indicates that in one study, 12% of patients with acute lymphoblastic leukemia (ALL) undergoing maintenance chemotherapy developed VOD. A significant risk factor for developing hepatopathy from these treatments is an age of less than 36 months.

Management

• The prognosis for untreated VOD is grim, with a mortality rate approaching 100%.
• Initial management steps include discontinuing any chemotherapeutic agents contributing to the condition.
• Treatment with Tissue Plasminogen Activator (TPA), heparin, and antithrombin III has been shown to offer a 10% survival rate 100 days post-BMT.
• The administration of Defibrotide, known for its fibrinolytic, antithrombotic, and anti-ischemic properties, has demonstrated a 35% survival rate, highlighting its potential as a more effective treatment option for VOD.

References

• Kaste SC, Rodriguez-Galindo C, Furman WL (1999) Pictorial essay: imaging pediatric oncologic emergencies of the abdomen. AJR Am J Roentgenol 173:729–736
• Pizzo PA (2021) Management of oncologic emergencies. In: Lanzkowsky P (ed) Manual of pediatric hematology and oncology, 8th edn. Elsevier, San Francisco