Multifocal lymphangioendotheliomatosis with thrombocytopenia

Clinical variability in multifocal lymphangioendotheliomatosis with thrombocytopenia: a review of the literature

Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is a recently recognized disorder characterized by vascular lesions marked by distinct endothelial proliferation. Lesions affect multiple tissues, and MLT can be associated with refractory thrombocytopenia resulting in life-threatening bleeding. Diagnosing MLT may be challenging given its rarity and phenotypic variability. There is no consensus on the optimal management or treatment duration. We report a 4-month-old male who presented with multiple vascular malformations involving the gastrointestinal tract, lung, bones, choroid plexus, and spleen, with minimal cutaneous involvement and no thrombocytopenia. Wedge resection of a pulmonary nodule was strongly positive for lymphatic vessel endothelial hyaluronan receptor 1 favoring MLT despite the lack of thrombocytopenia. The patient's clinical symptoms and vascular lesions improved on sirolimus therapy. We review the literature to highlight the clinical variability of MLT and discuss the diagnostic and therapeutic options for MLT.

BENIGN LYMPHANGIOENDOTHELIOMA

The authors describe modern data relating to the definition, clinical, pathological and immunohistochemical features of a rare vascular tumor — benign lymphangioendothelioma. The problems of differential diagnosis with Kaposi’s sarcoma and angiosarcoma are discussed. This is the first description of this tumorin domestic literature.

Multifocal Lymphangioendotheliomatosis with Thrombocytopenia: Presentation of Two Cases Treated with Sirolimus

Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is a rare disease characterized by congenital and progressive vascular lesions of the skin and gastrointestinal tract that may be associated with thrombocytopenia and possibly life-threatening gastrointestinal bleeding. Reports published on the disease and treatment strategies are scarce. We present two cases of MLT treated with sirolimus.

Multifocal Lymphangioendotheliomatosis With Thrombocytopenia: Clinical Features and Response to Sirolimus

Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is a recently described glucose transporter 1-negative multifocal vascular disorder with significant morbidity and mortality. However, data are lacking on the clinical spectrum, long-term prognosis, and treatment of MLT. It is often confused with multifocal infantile hemangioma, but the conditions must be differentiated for appropriate assessment and therapeutic management. Treatments for MLT have been disappointing, and the treatments classically used for infantile hemangioma are often ineffective. We report 3 newborn cases featuring various clinical and biological phenotypes of MLT: 1 patient had severe brain involvement and died early; another had no thrombocytopenia; and the third had nearly no skin involvement. Histologically, all were negative for glucose transporter 1 and positive for the lymphatic marker lymphatic vessel endothelial hyaluronan receptor 1 or D2-40 (∼38-kDa O-linked transmembrane sialoglycoprotein podoplanin). Two cases with severe gastrointestinal bleeding were treated with sirolimus 0.1 mg/k per day, which was efficient after the first month of treatment. MLT clinically presents in various forms, and when complicated by widespread or severe extracutaneous involvement, initial aggressive therapeutic intervention is justified. The pathogenesis of MLT remains unclear, but lymphatic differentiation is widely acknowledged. Because of its antiangiogenic properties, including anti-lymphangiogenesis, sirolimus offers an adequate and targeted therapeutic approach for MLT.

Diagnosis and management of infantile hemangiomas

Propranolol has replaced corticosteroids as preferred first-line therapy for the management of infantile hemangiomas (IH). The topical β-blocker timolol is now an alternative to oral propranolol and watchful waiting for smaller IH. Research in the last decade has provided evidence-based data about natural history, epidemiology, and syndromes associated with IH. The most pressing issue for the clinician treating children with IH is to understand current data to develop an individualized risk stratification for each patient and determine the likelihood of complications and need for treatment. This article emphasizes the nuances of complicated clinical presentations and current treatment recommendations.

Multifocal lymphangioendotheliomatosis with devastating intracranial hemorrhage

An in utero female was found to have a small hemorrhage at the foramen of Monro, hydrocephalus, and what was originally interpreted as a Dandy-Walker variant. At birth she had macrocephaly and numerous cutaneous, multifocal, red-pink blanchable macules. Postnatal MRI demonstrated a hemorrhagic soft-tissue mass involving the upper brainstem, thalamus, and basal ganglia most consistent with in utero complex multifocal intracranial hemorrhage. The skin lesions were thought to be consistent with multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT). The size and location of the hemorrhage precluded operative intervention, although the hydrocephalus was treated with a ventricular shunt. The child continues to have severe developmental delays. Multifocal lymphangioendotheliomatosis with thrombocytopenia is a multifocal vascular disorder most commonly involving the skin and gastrointestinal tract. Intracranial hemorrhages are rare in this context. This case is the third reported instance of MLT with associated intracranial hemorrhage and the only case described in the neurosurgical literature. The authors review the presenting features and pathophysiology of this condition.

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Vincristine: Can its therapeutic index be enhanced?

Vincristine is one of the most widely used and more effective drugs in paediatric oncology. The dose-limiting toxicity of neuropathy, lack of proven neuroprotective measures and an incomplete understanding of the pharmacokinetics and pharmacogenetics of vincristine have limited its therapeutic potential. Recent advances in the understanding of vincristine pharmacokinetics and pharmacogenetics, and potential methods of preventing neurotoxicity are reviewed which could enable dose escalation and dose individualisation in order to enhance the therapeutic index.

Bevacizumab treatment in multifocal lymphangioendotheliomatosis with thrombocytopenia

Multifocal lymphangioendotheliomatosis with thrombocytopenia (MLT) is a rare disorder characterized by a proliferation of cutaneous and gastrointestinal (GI) lesions that have characteristics of both lymphatic and vascular lesions. Thrombocytopenia is associated with this syndrome and is thought to represent platelet destruction within the lesions. The natural history is one of multiple, life-threatening episodes of GI bleeding. We report the successful use of bevacizumab in this disease, an antibody to the vascular endothelial growth factor.

Expanding the phenotype of multifocal lymphangioendotheliomatosis with thrombocytopenia

Multifocal lymphangioendotheliomatosis with thrombocytopenia is characterized by vascular skin and gastrointestinal (GI) tract lesions, thrombocytopenia, and GI bleeding. The first patient had scattered red macules and subcutaneous nodules on the skin with involvement of the lungs, liver, omentum, and right kidney. At 10 months of age he continues to have severe GI bleeding. The second patient had innumerable vascular plaques on the skin plus muscle, bone, lung, liver, and brain involvement. She died from respiratory failure at 8 months of age due to brainstem involvement. Both patients required aggressive management of GI bleeding, but had quite different skin findings and long-term outcomes.

Glomuvenous malformation in a boy with transposition of the great vessels: a case report and review of literature

We report a case of glomuvenous malformation (GVM) in an 11-year-old boy with a history of transposition of the great vessels. The glomulin gene was discovered in 1999, and multiple mutations have been identified with some of the mutations resulting in GVM. The molecular genetics, clinical presentation, histopathology, differential diagnosis, and management of GVM are reviewed. To our knowledge, no case of glomuvenous malformation in the setting of transposition of the great vessels has ever been reported in the literature.