Laryngomalacia and Complicated, Life-threatening mTOR-positive Kaposiform Hemangioendothelioma Cured by Supraglottoplasty and Sirolimus

Abstract

The therapy of complicated Kaposiform hemangioendothelioma (KHE) is still difficult. We present the first case of laryngomalacia with simultaneous mammalian target of Rapamycin (mTOR)-positive KHE of the neck and thoracic inlet and concurrent Kasabach-Meritt Phenomenon (KMP) in an 11-month-old boy suffering life-threatening progress despite intravenous vincristine, corticosteroids, propranolol and local interstitial laser-application. The laryngomalacia restored after laser-supraglottoplasty. Successfully treatment of the prior fatal course of the KHE with KMP was initiated not till adding the mTOR inhibitor sirolimus to therapy. After 16 months single therapy of KHE with oral sirolimus the boy presented free of symptoms with minimal residual disease and excellent functional long-term results. Thus we stopped sirolimus therapy. The results are stable for 9 months without therapy. The special features including full report of histopathologic findings of this utmost complicated case are demonstrated in detail underlining the effectiveness of sirolimus for KHE.

Role of Sirolimus in Advanced Kaposiform Hemangioendothelioma

“…Sirolimus was chosen as a treatment option, given a growing body of work investigating its role in the management of complicated vascular tumors . Our patient's contracture and disability were felt to be secondary to the infiltrative nature of his tumor involving the soft tissue of his right thigh, but also the accompanying fibrosis that complicates KHE over time.…”

Sirolimus for the treatment of children with various complicated vascular anomalies

“…Since 2010, sporadic reports on the use of sirolimus in the management of KHE, a vascular tumor of borderline malignancy, confirm its effectiveness in this entity [2,10,14,23]. In 2011, Hammill et al reported on five patients with complicated lymphatic malformations and one patient with KHE who were treated with sirolimus after failing multiple other therapies [10].…”

“…In 2011, Hammill et al reported on five patients with complicated lymphatic malformations and one patient with KHE who were treated with sirolimus after failing multiple other therapies [10]. There are only sporadic further case reports on the use of sirolimus in children with different vascular anomalies, namely KHE and/or lymphatic malformations [13,15,23,28]. In accordance to these data, two patients with KHE and KMP in our series (patients 3 and 6) improved dramatically under sirolimus without experiencing any significant complications.…”

Clinical Review: Management of Adult Kasabach-Merritt Syndrome Associated with Hemangiomas

“…Review of available literature does not support an increased risk of bleeding with use of antiplatelet agents in KMS, especially when there is no active bleeding. Although the data is controversial, the combination of aspirin and Ticlopidine appears to be the safest and most effective option [76][77][78][79][80]. Enjolras et al reported that this combination was effective in 32% of patients in one series and 29% in another series [63,81,82].…”