Vascular anomalies require team approach

Over the past decade, new medications and clinical trials have put increasing numbers of vascular anomalies (VAs) under the purview of pediatric hematologists/oncologists. Because the heterogeneity of VA presentation creates diagnostic challenges, a recent review shares diagnostic and management advice while recommending a multidisciplinary approach.

Although VAs rarely cause death, these tumors and malformations often progressively worsen quality of life.¹ "Optimal care for these patients requires an interdisciplinary approach with input from medical, surgical and radiological experts, as well as other specialists," wrote authors led by Denise M. Adams, M.D., of Boston Children's Hospital and Harvard Medical School. Appearing in the June 2017 edition of Pediatric Blood & Cancer, the article features the following cases and clinical entities:

Kaposiform hemangioendothelioma (KHE) with kasabach-merritt phenomenon (KMP)

An enlarging lesion on the thigh of a 3-week old girl was firm, erythematous-violaceous and warm, extending to her labia and buttocks. MRI revealed an infiltrative lesion extending beyond the superficial cutaneous tissue. Diagnostic clues for KHE included the lesion's deep red-purple hue, infiltrative nature and ill-defined border.

KMP can occur with KHE and with tufted angiomas (TAs). KHE and TAs typically present at birth, with unifocal lesions involving the head and neck, trunk, extremities or retroperitoneum. KHEs of the retroperitoneum, neck or mediastinum carry high mortality. Restrict platelet transfusion to manage severe bleeding, and avoid periprocedural timing – tumors rapidly entrap transfused platelets, worsening KMP. According to a multidisciplinary consensus, therapy for KHE with KMP should start with combined steroids and vincristine (0.05 mg/kg /dose). "In recent years," authors added, "propranolol has been reported with mixed efficacy, but sirolimus has emerged as effective."^2,3 Chemotherapy and interferon also have shown success.

Venous malformation (VM) with localized intravascular coagulopathy (LIC)

A one-year-old boy with an enlarging bluish congenital lesion on his back was diagnosed clinically with KHE with KMP. After the patient failed vincristine and steroids, a second opinion provided by a multidisciplinary team diagnosed extensive VM complicated by LIC. Coagulopathy can increase risk of hematological complications, particularly during or after debulking surgery or invasive radiological procedures. "All patients with coagulopathy and extensive venous ectasia or undergoing major debulking surgery should be referred for hematology consultation." Lab tests for patients at risk of LIC include complete blood count, blood smear and basic coagulation panel. "There are currently no established protocols to treat coagulopathy in children with VMs," although recently developed consensus guidelines await publication. Sirolimus has been reported to improve pain and coagulopathy in VMs.

Hepatic hemangiomas

For hepatic hemangiomas, reports show success with steroids and propranolol (2-3 mg/kg/day). For rapidly involuting congenital hemangiomas (RICHs), involution takes an average of 16 months. Multifocal lesions typically require medical therapy only if clinically significant or associated with cutaneous lesions causing disfigurement or functional impairment. Screen infants with diffuse IHs for hypothyroidism; treat aggressively if found.

REFERENCES:

1. Wassef M, Blei F, Adams DM, et al. Vascular anomalies classification: recommendations from the International Society for the Study of Vascular Anomalies. Pediatrics. 2015;136(1):e203-e204.

2. Chiu YE, Drolet BA, Blei F, et al. Variable response to propranolol treatment of kaposiform hemangioendothelioma, tufted angioma, and Kasabach-Merritt phenomenon. Pediatr Blood Cancer. 2012;59:934-938.

3. Blatt J, Stavas J, Moats-Staats B, et al. Treatment of childhood kaposiform hemangioendothelioma with sirolimus. Pediatr Blood Cancer. 2010;55:1396-1398.