Response of Blue Rubber Bleb Nevus Syndrome to Sirolimus Treatment.

BACKGROUND: Blue rubber bleb nevus syndrome (BRBNS) is a rare multifocal venous malformation syndrome involving predominantly the skin and gastrointestinal tract. Traditional treatment modalities include corticosteroids, interferon-α, sclerotherapy, and aggressive surgical resection. Sirolimus has been used in several single case reports. PROCEDURE: We performed a single-institution retrospective review of four children with BRBNS, who received sirolimus as part of their treatment regimens. A diagnosis of BRBNS was based on clinical, radiologic, and pathologic criteria. RESULTS: Median age was 6.5 years (range: 2-16 years). Pathologic evaluations revealed a combined malformation with venous and lymphatic components. The novel finding of a lymphatic component was confirmed with PROX-1 immunostaining. Patients received oral sirolimus with target drug levels between 10 and 13 ng/ml. Responses to treatment were defined as stabilization/decrease in size of lesions; resolution of transfusion requirements; reduction in pain, and improvement in quality of life (QOL). Median time to response was 1.5 months (SD ± 0.96 month, range: 1-3 months). Median follow-up was 21 months (range: 18-26 months). Lesion size and characteristics improved in all patients. All patients reported decrease in pain and improvement in QOL. All three patients requiring transfusions became transfusion-independent. One patient had resolution of coagulopathy. Adverse effects of sirolimus consisted of mucositis in three patients and neutropenia in one patient. CONCLUSIONS: Sirolimus is safe and efficient for the treatment of BRBNS. Further prospective studies are needed to evaluate the long-term effectiveness of this drug. This is the first report that identifies a lymphatic component as part of BRBNS.

Infantile Hemangiomas in Twins: A Prospective Cohort Study.

BACKGROUND: Twins have a higher-than-expected risk of infantile hemangiomas (IHs), but the exact reasons for this association are not clear. Comparing concordant and discordant twin pairs might help elucidate these factors and yield more information about IH risk factors. METHODS: A prospective cohort study of twin pairs from 12 pediatric dermatology centers in the United States, Canada, Argentina, and Spain was conducted. Information regarding maternal pregnancy history, family history of vascular birthmarks, zygosity (if known), and pregnancy-related information was collected. Information regarding twins (N = 202 sets) included birthweight, gestational age (GA), presence or absence of IHs, numbers and subtypes of IHs, presence of other birthmarks, and other medical morbidities. RESULTS: Two hundred two sets of twins were enrolled. Concordance for IH was present in 37% of twin pairs. Concordance for IH was inversely related to gestational age (GA), present in 42% of GA of 32 weeks or less, 36% of GA of 33 to 36 weeks, and 32% of GA of 37 weeks or more. Twins of GA of 34 weeks or less were more than two and a half times as likely to be concordant as those of GA of 35 weeks or more (odds ratio (OR) = 2.66, 95% confidence interval (CI) = 1.42-4.99; p < 0.01). In discordant twins, lower birthweight conferred a high risk of IH; of the 64 sets of twins with 10% or greater difference in weight, the smaller twin had IH in 62.5% (n = 40) of cases, versus 37.5% (n = 24) of cases in which the higher-birthweight twin was affected. Zygosity was reported in 188 twin sets (93%). Of these, 78% were dizygotic and 22% monozygotic. There was no statistically significant difference in rates of concordance between monozygotic twins (43%, 18/42) and dizygotic twins (36%, 52/146) (p = 0.50). In multivariate analysis comparing monozygotic and dizygotic twins, adjusting for effects of birthweight and sex, the likelihood of concordance for monozygotic was not appreciably higher than that for dizygotic twins (OR = 1.14, 95% CI = 0.52-2.49). Female sex also influenced concordance, confirming the effects of female sex on IH risk. The female-to-male ratio was 1.7:1 in the entire cohort and 1.9:1 in those with IH. Of the 61 concordant twin sets with known sex of both twins, 41% were female/female, 43% were female/male, and 16% were male/male. CONCLUSIONS: These findings suggest that the origin of IHs is multifactorial and that predisposing factors such as birthweight, sex, and GA may interact with one another such that a threshold is reached for clinical expression.

The role of the hematologist/oncologist in the care of patients with vascular anomalies.

Pediatric hematologist/oncologists have a critical role in the diagnosis and management of patients who have complex vascular anomalies. They provide the clinical and medical skills needed to diagnose, treat, and manage these patients. Hematologist/oncologists also provide support for clinical trials and drug development to further treatment options for these patients.

Efficacy and Safety of Sirolimus in the Treatment of Complicated Vascular Anomalies.

BACKGROUND AND OBJECTIVES: Complicated vascular anomalies have limited therapeutic options and cause significant morbidity and mortality. This Phase II trial enrolled patients with complicated vascular anomalies to determine the efficacy and safety of treatment with sirolimus for 12 courses; each course was defined as 28 days. METHODS: Treatment consisted of a continuous dosing schedule of oral sirolimus starting at 0.8 mg/m(2) per dose twice daily, with pharmacokinetic-guided target serum trough levels of 10 to 15 ng/mL. The primary outcomes were responsiveness to sirolimus by the end of course 6 (evaluated according to functional impairment score, quality of life, and radiologic assessment) and the incidence of toxicities and/or infection-related deaths. RESULTS: Sixty-one patients were enrolled; 57 patients were evaluable for efficacy at the end of course 6, and 53 were evaluable at the end of course 12. No patient had a complete response at the end of course 6 or 12 as anticipated. At the end of course 6, a total of 47 patients had a partial response, 3 patients had stable disease, and 7 patients had progressive disease. Two patients were taken off of study medicine secondary to persistent adverse effects. Grade 3 and higher toxicities attributable to sirolimus included blood/bone marrow toxicity in 27% of patients, gastrointestinal toxicity in 3%, and metabolic/laboratory toxicity in 3%. No toxicity-related deaths occurred. CONCLUSIONS: Sirolimus was efficacious and well tolerated in these study patients with complicated vascular anomalies. Clinical activity was reported in the majority of the disorders.

Noninterventional treatment of selected head and neck lymphatic malformations.

BACKGROUND: Indications for treatment of lymphatic malformations include disfigurement, symptoms, and infection. Patients with lymphatic malformations often undergo resection or sclerotherapy to prevent possible complications, as it has been thought that lymphatic lesions do not regress. METHODS: A retrospective analysis of all head and neck lymphatic malformations for the past 5 years was performed. RESULTS: Twenty-five patients with lymphatic malformations of the head and neck were treated, all underwent computed tomography or magnetic resonance imaging for evaluation. Fourteen patients had macrocystic lesions; others were considered mixed or microcystic. Seventeen patients underwent intervention. Ten patients underwent surgical resection alone, 4 patients underwent sclerotherapy, and 3 patients had both sclerotherapy and surgical resection. Of 17, 15 patients who underwent intervention had complications, including recurrence and nerve damage. Eight patients with predominantly macrocystic lesions were managed with close observation and were asymptomatic other than a mass. With follow-up of 33.4 months, in 4 of 8 patients, the lesion significantly decreased; 4 of 8 patients continue to be asymptomatic. CONCLUSIONS: Patients who undergo intervention have a high complication and recurrence rate. Selected patients with asymptomatic macrocystic lymphatic malformations of the head and neck can often be managed by observation alone. These patients should be followed closely in a multidiscliplinary clinical setting.