The role of key biomarkers in lymphatic malformation: An updated review.

The lymphatic system, crucial for tissue fluid balance and immune surveillance, can be severely impacted by disorders that hinder its activities. Lymphatic malformations (LMs) are caused by fluid accumulation in tissues owing to defects in lymphatic channel formation, the obstruction of lymphatic vessels or injury to lymphatic tissues. Somatic mutations, varying in symptoms based on lesions' location and size, provide insights into their molecular pathogenesis by identifying LMs' genetic causes. In this review, we collected the most recent findings about the role of genetic and inflammatory biomarkers in LMs that control the formation of these malformations. A thorough evaluation of the literature from 2000 to the present was conducted using the PubMed and Google Scholar databases. Although it is obvious that the vascular endothelial growth factor receptor 3 mutation accounts for a significant proportion of LM patients, several mutations in other genes thought to be linked to LM have also been discovered. Also, inflammatory mediators like interleukin-6, interleukin-8, tumor necrosis factor-alpha and mammalian target of rapamycin are the most commonly associated biomarkers with LM. Understanding the mutations and genes expression responsible for the abnormalities in lymphatic endothelial cells could lead to novel therapeutic strategies based on molecular pathways.

Targeted treatment in complex lymphatic anomaly: a case of synergistic efficacy of trametinib and sirolimus.

Repurposing anticancer drugs to vascular malformations has significantly improved patient outcomes. Complex Lymphatic Anomalies (CLA) are part of the spectrum of lymphatic malformations (LMs) that share similar oncogenic mutations to cancer. We report the case of a young patient with highly symptomatic CLA who was initially treated with sirolimus, due to the frequent involvement of the PI3K-AKT-mTOR pathway in CLA pathogenesis. Despite an initial reduction in symptoms, sirolimus progressively lost its effectiveness. After an unsuccessful attempt with trametinib alone, sirolimus was added to trametinib and resulted in a significant, rapid and sustained improvement in symptoms. This suggests that, contrary to current dogmas, combination therapy using sub-therapeutic doses targeting both the PI3K and RAS pathways retains efficacy without generating the toxicity known for combination therapies, and is beneficial in the management of CLAs and potentially other vascular anomalies.

A multi-step approach to overcome challenges in the management of head and neck lymphatic malformations, and response to treatment.

BACKGROUND: Lymphatic malformations are vascular developmental anomalies varying from local superficial masses to diffuse infiltrating lesions, resulting in disfigurement. Patients' outcomes range from spontaneous regression to severe sequelae notwithstanding appropriate treatment. The current classification guides, in part, clinicians through the decision-making process, prognosis prediction and choice of therapeutic strategies. Even though the understanding of molecular basis of the disease has been recently improved, a standardized management algorithm has not been reached yet. RESULTS: Here, we report our experience on five children with different lymphatic anomalies of the head and neck region treated by applying a multidisciplinary approach reaching a consensus among specialists on problem-solving and setting priorities. CONCLUSIONS: Although restitutio ad integrum was rarely achieved and the burden of care is challenging for patients, caregivers and healthcare providers, this study demonstrates how the referral to expert centres can significantly improve outcomes by alleviating parental stress and ameliorating patients' quality of life. A flow-chart is proposed to guide the multidisciplinary care of children with LMs and to encourage multidisciplinary collaborative initiatives to implement dedicated patients' pathways.

Differential Diagnosis of Generalized Cystic Lymphangiomatosis: A Literature Review.

BACKGROUND: Generalized cystic lymphangiomatosis (GCL) is a rare disease characterized by the widespread proliferation of lymphatic vessels, often seen in the pediatric patient group. Imaging techniques are instrumental in revealing the extent and morphological features of the disease. OBJECTIVE: The objective of this study is to interpret the radiological findings of GCL and address the differential diagnosis between GCL and other lymphatic malformations in light of the relevant literature data. METHODS: The sample of this retrospective study consisted of six pediatric patients, four males and two females, diagnosed with GCL based on clinical, radiological, and histopathological findings between 2015 and 2022. The age of the patients at the time of diagnosis and their symptoms at admission were obtained from the hospital database. Radiological imaging findings were evaluated in detail based on the involved systems (thorax, abdomen, and musculoskeletal). RESULTS: The median age of the sample, 4/6 were male, was 9 years at admission (min. 3, max. 12). The most common symptom at admission was dyspnea, often accompanied by pleural effusion. Bone involvement was the most common extrathoracic finding. Abdominal involvement was primarily asymptomatic, and the spleen was the most frequently involved organ in the abdomen. CONCLUSION: The diagnosis of GCL is challenging because of its rarity and overlapping diseases. Whole-body magnetic resonance imaging is a valuable tool as it reveals the typical radiological features of GCL and how far it has spread throughout the body.

Sequential MRI Evaluation of Lymphatic Abnormalities over the Course of Fontan Completion.

Purpose To evaluate lymphatic abnormalities before and after Fontan completion using noncontrast lymphatic imaging and relate findings with postoperative outcomes. Materials and Methods This study is a retrospective review of noncontrast T2-weighted lymphatic imaging performed at The Children's Hospital of Philadelphia from June 2012 to February 2023 in patients with single ventricle physiology. All individuals with imaging at both pre-Fontan and Fontan stages were eligible. Lymphatic abnormalities were classified into four types based on severity and location of lymphatic vessels. Classifications were compared between images and related to clinical outcomes such as postoperative drainage and hospitalization, lymphatic complications, heart transplant, and death. Results Forty-three patients (median age, 10 years [IQR, 8-11]; 20 [47%] boys, 23 [53%] girls) were included in the study. Lymphatic abnormalities progressed in 19 individuals after Fontan completion (distribution of lymphatic classifications: type 1, 23; type 2, 11; type 3, 6; type 4, 3 vs type 1, 10; type 2, 18; type 3, 10; type 4, 5; P = .04). Compared with individuals showing no progression of lymphatic abnormalities, those progressing to a high-grade lymphatic classification had longer postoperative drainage (median time, 9 days [IQR, 6-14] vs 17 days [IQR, 10-23]; P = .04) and hospitalization (median time, 13 days [IQR, 9-25] vs 26 days [IQR, 18-30]; P = .03) after Fontan completion and were more likely to develop chylothorax (12% [three of 24] vs 75% [six of eight]; P < .01) and/or protein-losing enteropathy (0% [0 of 24] vs 38% [three of eight]; P < .01) during a median follow-up of 8 years (IQR, 5-9). Progression to any type was not associated with an increased risk of adverse events. Conclusion The study demonstrated that lymphatic structural abnormalities may progress in select individuals with single ventricle physiology after Fontan completion, and progression of abnormalities to a high-grade classification was associated with worse postoperative outcomes. Keywords: Congenital Heart Disease, Glenn, Fontan, Lymphatic Imaging, Cardiovascular MRI Supplemental material is available for this article. Published under a CC BY 4.0 license.

Experiencia con OK-432 en malformaciones vasculares linfáticas en un hospital del norte de México / Experience with OK-432 in lymphatic vascular malformations in a hospital from northern Mexico

Resumen Introducción: Las malformaciones vasculares linfáticas (MVL), anteriormente llamadas linfangiomas, son malformaciones congénitas que se presentan en uno de cada 6,000 a 16,000 nacimientos. El sistema de clasificación más útil para el manejo del linfangioma se basa en el tamaño de los quistes. La resolución espontánea es infrecuente, por lo que el tratamiento expectante no se recomienda. El tratamiento clásico es la cirugía de escisión, pero puede afectar a estructuras vecinas o haber recidivas, por lo que se empezaron a estudiar sustancias esclerosantes, como el OK-432. La mayoría de los estudios incluyen pocos pacientes; los más grandes realizados en México se enfocan a lesiones específicas (macroquísticas) o únicamente a una región anatómica. Hasta la fecha, no existen estudios del uso de este fármaco en la población del norte de México. Método: Se describe la experiencia con OK-432 mediante un estudio retrospectivo, descriptivo, en los pacientes con MVL, de 2011 a 2016, en un hospital de referencia del norte de México. Resultados: Veintiséis pacientes con MVL recibieron tratamiento con OK-432. La mayoría fueron macroquísticos (69%), microquísticos (19%) y mixtos (12%). Del total de pacientes, 11 presentaron curación total. El 72% de la población estudiada tuvo una reducción de > 50% del tamaño de las lesiones con solo dos aplicaciones de tratamiento; no se presentaron recidivas. Se reportaron complicaciones en dos pacientes (hiperpigmentación de la piel). Conclusiones: El manejo con OK-432 demostró ser efectivo para el tratamiento de las MVL en un hospital de referencia del norte de México.

Abstract Background: Lymphatic vascular malformations (LVM) or formerly called lymphangiomas are congenital malformations present in about 1 out of 6000 to -16000 births. The most relevant classification system for lymphangioma management is based on the size of the cysts. Spontaneous resolution is uncommon; thus, expectant management is not recommended. The classic treatment is excisional surgery, but it can affect adjacent structures or have relapses, so, sclerosing substances like OK-432 are being studied. The majority of the studies are small in number of patients and are from Japan; the largest studies in Mexico are focused on specific lesions (macrocystic) or a determined anatomical region. To date, there are no studies of the population of the north of Mexico. Methods: The experience with OK-432 was described through a retrospective, descriptive study in patients with LVM, from 2011 to 2016, in a reference hospital of northern Mexico. Results: A total of 26 patients with LVM were treated with OK-432. The majority of the lesions were macrocystic (69 %), microcystic (19 %) and mixed (12 %). From the total number of patients, 11 fully healed, and 72 % of the study population had >50 % reduction in lesion size, with only 2 applications. There were no recurrences. Complications were reported in 2 patients who had skin hyperpigmentation. Conclusions: OK-432 probed to be an effective treatment for LVM in a reference hospital in the north of Mexico.

Tratamento intralesional de malformações linfáticas com ênfase na escleroterapia com picibanil (OK-432): revisão sistemática / Intralesional treatment of lymphatic malformations with emphasis on Picibanil (OK-432) sclerotherapy: a systematic review

INTRODUÇÃO: Conduziu-se revisão sistemática retrospectiva da literatura incluindo estudos relatando o uso de picibanil para tratar malformações linfáticas (ML). MÉTODOS: A pesquisa foi realizada com estudos publicados no PubMed de janeiro de 1990 a 14 de abril de 2013. Na estratégia de busca, usou-se os descritores "OK-432" ou "Picibanil" e "lymphatic malformation". Os seguintes elementos foram comparados aos de outras modalidades relatadas e, então, compilados: mecanismo de ação, indicações, contraindicações, eficácia, administração, efeitos colaterais, complicações, vantagens e desvantagens. RESULTADOS: Foram encontrados 44 estudos, 27 dos quais atenderam aos critérios de inclusão. O picibanil é uma preparação liofilizada de uma cepa de baixa virulência de Streptococcus pyogenes inativada pela penicilina G. Seu mecanismo de ação ainda não definido claramente, mas especula-se que provoque uma resposta inflamatória controlada com adesão das paredes dos cistos. O picibanil é indicado quase que unanimemente para o tratamento da ML macrocística, cuja resposta é mais efetiva do que em lesões microcísticas ou mistas. Em geral, o picibanil é administrado por meio de punção com visualização direta ou guiada por ultrassonografia, com o paciente sob anestesia geral. A preparação comumente utilizada consiste em 0,1 mg de picibanil em 10 ml de soro fisiológico. Os efeitos colaterais são, em geral, leves; sendo dor, inchaço e febre os mais frequentemente relatados. CONCLUSÃO: Os estudos apresentam pouca evidência científica. A revisão sistemática identificou que o picibanil é útil no tratamento da ML de qualquer tipo, mas tem resultados melhores em lesões macrocísticas. A eficácia foi comparável à de outras terapias. Não foi apresentada nenhuma contraindicação específica. Embora o mecanismo de ação ainda não tenha sido determinado, o picibanil trata-se de opção de tratamento.

INTRODUCTION: We performed a retrospective systematic review of studies reporting the use of Picibanil for treatment of lymphatic malformations (LMs). METHODS: We searched the PubMed database for available studies, including those published between January 1990 and April 14, 2013. The search strategy involved the use of the keywords "OK-432" or "Picibanil" and "lymphatic malformation." Information was compiled regarding the reported mechanism of action, indications, contraindications, efficacy, administration, side effects, complications, and advantages and disadvantages compared to those of other modalities. RESULTS: Forty-four studies were found, of which 27 fulfilled the inclusion criteria. Picibanil is a lyophilized preparation of a low-virulence strain of Streptococcus pyogenes inactivated with penicillin G. Its mechanism of action is unclear, but it has been speculated that it causes a controlled inflammatory response with adhesion of cyst walls. Picibanil is almost unanimously indicated for the treatment of macrocystic LMs, which show a greater effectiveness response compared to that shown by microcystic or mixed LMs. Picibanil is usually administered by puncturing, either with direct visualization or guided by ultrasound, with the patient under general anesthesia. The most widely used preparation comprises 0.1 mg of Picibanil in 10 mL of saline. Side effects are mostly mild, with pain, swelling, and fever being the most frequently reported. CONCLUSION: The studies had low scientific evidence. A systematic review found that Picibanil is useful against any LM, with better results in macrocystic lesions. Efficacy was comparable to that of other therapies. No specific contraindication was presented. Although the mechanism of action has not been established, the inclusion of Picibanil as a treatment option is warranted.

Malformación linfática facial mixta: Caso clínico / Mixed facial lymphatic malformation: Case report

Lymphangiomas are a common form of vascular malformation of the lymphatic vessels, mainly in the head and neck region. Most cases are progressive evolution and require a multidisciplinary approach. Currently, the first therapeutic option is sclerotherapy, leaving surgery for the treatment of remaining lesions. Objective: To present a case of facial lymphatic malformation (LM) treated with sclerotherapy, surgery and orthodontics in a 15-year follow up. Case report: A one-year-old female patient who consulted health professionals due to a progressive volume increase of the soft parts of her right cheek. The imaging study confirmed the diagnosis of microcystic lymphatic malformation. It was managed with OK-432 sclerotherapy and Bleomycin. At 2 years of age, the patient response was considered adequate; an intralesional submandibular surgical excision was then performed, with partial resection of the lesion. The biopsy confirmed the diagnosis of microcystic LM. Six months after, a re-resection was planned using the same approach and removing the remaining lesion, with favorable development until the age of 9 years when the patient required surgery and orthodontic management due to intraoral recurrence. No major developments until the age of 13 when a new orthodontic surgery and handling are planned to perform right oral commissure suspension. Conclusion: LM management by sclerotherapy, surgery, and orthodontics has shown the advantages of a multidisciplinary long-term treatment in this case.

El linfangioma corresponde a una malformación vascular de los vasos linfáticos, preferentemente de la región de cabeza y cuello. La mayoría de los casos son de evolución progresiva y requieren un manejo multidisciplinario. Actualmente la primera opción terapéutica es la esclerosis, reservando la cirugía para el tratamiento de las lesiones remanentes. Objetivo: Presentar un caso de malformación linfática (ML) facial, tratado con escleroterapia, cirugía y ortodoncia en un seguimiento a 15 años. Caso clínico: Paciente de sexo femenino que consulta al año de edad por aumento de volumen progresivo de partes blandas en su mejilla derecha. El estudio de imágenes confirmó el diagnóstico de Malformación Linfática microquística. Se manejó con esclerosis seriada con OK-432 y Bleomicina. A los 2 años de edad se consideró que la respuesta era adecuada, y se procedió a realizar extirpación quirúrgica intralesional submandibular, con resección parcial de la lesión. La biopsia confirmó el diagnóstico de ML microquística. Seis meses después se planificó nueva resección utilizando el mismo abordaje y extirpando lesión remanente, con evolución favorable hasta la edad de 9 años en que requiere cirugía y manejo por ortodoncia, por recidiva de lesión a nivel intraoral. Evolución favorable hasta que a la edad de 13 años se planifica nueva cirugía y manejo por ortodoncia para suspender la comisura bucal derecha. Conclusión: El manejo de la ML mediante escleroterapia, cirugía, y ortodoncia muestra en este caso las ventajas de un tratamiento multidisciplinarion a largo plazo.