New Frontiers in Our Understanding of Lymphatic Malformations of the Head and Neck: Natural History and Basic Research

Oral Lymphatic Malformations: A 21-Year Retrospective Study in a Single Institution

Introduction. Oral lymphatic malformations are uncommon lesions. This study assessed the clinicopathological and sociodemographic features of oral lymphatic malformations in a Brazilian oral pathology service. Methods. Between 2000 and 2021, all oral lymphatic malformations diagnosed in a single oral pathology service were selected for the study. Clinical data, such as age, sex, site of the lesion, clinical presentation, diagnosis clinical, and the type of biopsy were recorded from the patient's clinical charts. Results. From 7554 oral lesions, 17 (0.22%) were oral lymphatic malformations. This lesion similarly affected both sexes, and the mean age of the patients was 16.5 years. The tongue was the most common site (n = 13; 76%). The mean size of the lesions was 17 mm. Oral lymphatic malformations were asymptomatic for 29% of the patients. Clinically, most lesions appeared as a reddish, sessile nodule, with a pebbly surface. In addition, the clinical and histopathological diagnoses agreed for most lesions (n = 11; 64%). The type of biopsy performed was excisional in 41% of lesions. Conclusions. In summary, oral lymphatic malformations present a low prevalence among the oral lesions diagnosed in an oral pathology service. Moreover, they affect equally both sexes, especially young patients, and usually appear as an asymptomatic or symptomatic nodular swelling on the tongue.

New Insights into Cervicofacial Vascular Anomalies

Congenital cervicofacial vascular anomalies are extremely rare and present many difficulties in diagnosis and treatment requiring a multidisciplinary approach. Firstly, there is little consensus on this subject among head and neck specialists. There are two main types of vascular anomalies: vascular tumors and vascular malformations. Vascular malformations are also divided into malformations with slow blood flow (veins, lymphatics, capillaries or combined) and malformations with a fast blood flow (arteriovenous malformations and fistula). Vascular tumors like hemangiomas are known for their spontaneous involution with aging, while vascular malformations grow in dimensions with age. It is very important to choose the correct differential diagnosis between cervicofacial hemangiomas and vascular malformations for proper therapy management. Anamnesis and clinical exams help in raising suspicions about the real nature of a cervico-vascular anomaly. Furthermore, imaging brings in-depth details of the anomaly, ranging from ultrasound and contrast CT to MRI scanning and minimally invasive angiography. Angiography with selective embolization is rarely a curative procedure for arteriovenous malformations, being more suitable as a preliminary step before attempted surgical removal. Surgery is clearly necessary when there are aesthetic and functional deficits. Slow-flow vascular malformations present a reduced morbidity, and in cases without involution, the surgical ablation is reserved for the cases with aesthetic dysfunctions or psychological trauma. Lymphatic malformations must undergo surgical ablation when they are associated with mass effects and compression of great vessels or aerial viscera. The prognosis after surgical removal is good, with a low rate of recurrence or morbidity. Fast-flow vascular malformations require a combined approach, with embolization and excision in the next 48 h for safety reasons. Removal may be followed by reconstructive surgery depending on the location and dimensions of the malformation, with a possible secondary recovery of the normal microscopic vessels. Some of the masses may hinder the normal airflow and swallowing. Pathology is the gold standard for confirming the clinical and imaging diagnosis.

[The Duplicity of Incidents: Cervical Lymphatic Malformation in two Newborns]

We report on two neonates born the same day, both with an isolated cervical lymphatic malformation. Cervical masses were detected by ultrasound late in the third trimester. Following interdisciplinary case conferences, a caesarean section in the presence of a neonatal team was the chosen delivery mode in both cases. Delivery and transition of the newborns were uneventful. The suspected diagnosis was confirmed by postnatal MRIs, which demonstrated neither associated malformations nor compression of vital structures. Therefore, an expectant approach was chosen for the newborn with the smaller lesion. The other newborn featured a sizeable lymphatic malformation, and due to consecutive head tilt, sclerotherapy was initiated in its second week of life. Our case report outlines the challenges of a rare connatal malformation. Guidelines are often missing. Individual decisions regarding delivery mode, diagnostics and therapy have to be made on an interdisciplinary basis and patients as well as parents need counseling and support over a long period. All the more significant is good, interdisciplinary collaboration between the involved disciplines.

Hamartomas, choristomas, and teratomas of the oral cavity: A 49-years cross-sectional study in an oral diagnostic service

BACKGROUND

To investigate the incidence and demographic profile of hamartomatous, choristomatous, and teratoid lesions in a Brazilian population over a 49 years-period.

METHODS

A retrospective cross-sectional study was performed, and data regarding demographic and clinical aspects were obtained from the medical records of a [removed for blind peer review] referral center (1970-2019). The collected data were submitted to descriptive analysis and Pearson's chi-square, Fisher's exact, and Kruskal-Wallis tests (p ≤ 0.05).

RESULTS

In a total of 16,412 medical records analyzed, 300 (1.83 %) were hamartomatous, 2 (0.01 %) choristomatous, and 1 (0.01 %) teratoid lesions. Hamartomas were most diagnosed in females and adults. Statistical significance was observed between hamartoma and age group (p < 0.001). Odontoma was the most frequent hamartomatous lesion. In choristomatous and teratoid lesions, there was no occurrence in males. The jaws were the most affected anatomical site by hamartoma. Choristomas were observed on the mandible and tongue, while a teratoid lesion was seen on the floor of the mouth.

CONCLUSIONS

Low occurrence of choristomatous and teratoid lesions over hamartomatous lesions and a heterogeneous occurrence profile regarding sex, age group, and anatomic site were observed. Hamartomas are relatively common and benign conditions that may cause damage and require special care during dental treatment. Thus, the dentist needs to be able to identify and treat them appropriately. Likewise, although choristomas and teratomas present no risk to patients and have a lower occurrence than hamartomas, they also require treatment.

The value of MRI in the diagnosis of pediatric head and neck lymphatic malformations: A study of 46 surgical cases

Objective To discuss the value of MRI in diagnosing and evaluating the pediatric head and neck lymphatic malformations (HNLMs). Methods We performed a retrospective review of 46 children who were referred to our hospital in the last decade for the treatment of HNLMs. Results About 34 cases confirmed with intralesional hemorrhage while the capsule contents were dark red or light bloody liquid. The remaining 12 pure HNLMs were filled with yellow clear or watery liquid. The multilocular HNLMs accounted for 95.7 % (44/46). The accuracy of contrast enhanced MRI (CE-MRI) diagnosis of HNLMs was 100 %. On MRI, the HNLMs appeared as irregular shape [95.7 % (44/46)], clear boundary [91.3 % (42/46)], infiltrative growth [91.3 % (42/46)] cystic masses. The cystic wall and septa were hyperintense on T1WI and hypointense on T2WI (100 %), and displayed enhancement. The capsule contents had hypointense on T1WI and hyperintense on T2WI in 18 cases (pure HNLMs,12; intracystic hemorrhage,6), while that of mixed signal in 28 cases (pure HNLMs,0; intracystic hemorrhage,28). Capsule contents were enhanced in 22 cases (pure HNLMs,1; intracystic hemorrhage,21), while the remaining 24 without enhancement (pure HNLMs,11; intracystic hemorrhage,13). Liquid-liquid levers were found in 21 cases (pure HNLMs,0; intracystic hemorrhage,21). There were statistical differences in capsule contents signal, enhancement, and liquid-liquid levels between the two groups (P < 0.05). Conclusions On MRI, HNLMs typically show a thin-walled, well-circumscribed, irregularly shaped, infiltrative, unenhanced, multilocular cystic mass with hypointense on T1WI and hyperintense on T2WI. The capsule wall and septa are hyperintense on T1WI, hypointense on T2WI, and display enhancement. Changes in the signal of capsule contents or appearance of liquid-liquid levels indicate intracystic hemorrhage.

Percutaneous sclerotherapy for head and neck lymphatic malformations in neonates and infants ≤12 months of age

BACKGROUND

Percutaneous sclerotherapy is an effective treatment for lymphatic malformations (LM) of the head and neck in adults. The purpose of this study was to examine the indications and efficacy of sclerotherapy for head/neck LM in the neonate and infant population.

METHODS

We retrospectively reviewed patients treated with percutaneous sclerotherapy for LM of the head/neck at age ≤12 months at a single vascular anomalies clinic. The clinical, anatomic, and technical aspects of each treatment, complications, and post-treatment clinical and imaging outcomes were analyzed.

RESULTS

22 patients underwent 36 treatments during the first year of life. Median age at first treatment was 6.2 months (range 2-320 days). Severe airway compromise was the most frequent indication for treatment (31.8%). Sclerosants included doxycycline (80.5%), sodium tetradecyl sulfate (55.5%), bleomycin (11.1%) and ethanol (2.8%). There were no immediate procedure-related complications; sclerosant-related laboratory complications included transient metabolic acidosis (8.3%) and hemolytic anemia (5.5%). Median follow-up was 3.7 years (IQR 0.6-4.8). 47.6% of patients showed >75% lesion size reduction and 19.0% showed minimal response (<25% improvement). At last follow-up, 71.4% of children were developmentally normal and asymptomatic, 23.8% had recurring symptoms, and 4.8% required permanent tracheostomy. Patients with ongoing symptoms or limited response to percutaneous sclerotherapy (33.3%) were treated with long-term sirolimus.

CONCLUSIONS

Percutaneous sclerotherapy is a safe and effective treatment for symptomatic LM of the head and neck in neonates and infants. Treatment strategy and management of recurrent symptoms requires consensus from an experienced, multidisciplinary team.

Management of the head and neck lymphatic malformations in children: A 7-year experience of 91 surgical cases

OBJECTIVE

To review the clinical characteristics and treatment outcomes of head and neck lymphatic malformations (HNLMs) in children.

METHODS

A retrospective study of 91 patients with HNLMs was performed.

RESULTS

The age ranged from 1 day to 14 years, of which 82.4 % (75/91) were under 2 years old and 45.1 % (41/91) were diagnosed at birth. The diagnostic rates of ultrasound, CT and MRI were 80.2 % (73/91), 90.1 % (82/91) and 100 % (8/8) respectively. There were 2 cases of complete excision, 8 of bleomycin sclerotherapy, and 81 of subtotal resection combined with bleomycin irrigation. Followed up for 3-93 months, all 91 cases were cured.

CONCLUSIONS

HNLMs mostly occur within 2 years old, and nearly half of them are present at birth. Characteristic imaging findings can assist clinicians in diagnosis and treatment plan. Subtotal resection combined with bleomycin irrigation may be an appropriate first-line therapy for HNLMs involving the vital anatomical structures.

Review of diagnosis, differential diagnosis, and management of retroperitoneal lymphangioma

Lymphatic malformation (LM) is the currently preferred term for what was previously known as lymphangioma. Retroperitoneal LMs are extremely rare, benign, cystic masses that arise from lymphatic vessels. They can be challenging to diagnose because they resemble other retroperitoneal cystic tumors. The development of treatment strategies for rare diseases, including retroperitoneal LM, requires the acquisition of new knowledge to enhance our understanding of the disease progression. Therefore, we present an update regarding fundamental and advanced issues associated with retroperitoneal LM. This review describes the epidemiology, histopathology, biomedicine, clinical manifestations, radiological features, differential diagnosis, and management of this lesion.

Sudden Appearance of a Palpable Chest Wall Mass Secondary to Macrocystic Lymphatic Malformation: A Case Report

Chest wall lymphatic malformations are rare and can pose a diagnostic dilemma, particularly if they present abruptly. This case report describes a 15-month-old male toddler presenting with a left lateral chest mass. Histopathology of the surgically excised mass confirmed the diagnosis of a macrocystic lymphatic malformation. Furthermore, there was no recurrence of the lesion in the two-year follow-up period.

French national diagnosis and care protocol (PNDS, protocole national de diagnostic et de soins): cystic lymphatic malformations

Cystic lymphatic malformations (LMs) are rare chronic conditions which management differs according to the type (macrocystic LMs, microcystic LMs or both). Studies are lacking due to rarity of the pathology. We aimed to establish a French National Diagnosis and Care Protocol (PNDS: Protocole National de Diagnostic et de Soins), to provide health professionals with free open access synthesis on optimal management and care of patients with LMs ( https://www.has-sante.fr/upload/docs/application/pdf/2021-03/malformations_lymphatiques_kystiques_-_pnds.pdf ). The process included a critical review of the literature and multidisciplinary expert consensus. LMs are congenital but are not always discovered at birth. Nearly 75% of them are located in the head and neck because of the highly dense lymphatic system in this region. Physical examination (showing painless masses with normal skin color and depressible consistency, or cutaneous/mucosal lymphangiectasia) and color Doppler ultrasonography, usually allow for diagnosis. MRI (involving T2 sequences with fat saturation in at least two spatial planes) is the tool of choice for evaluating anatomical extension, characterizing lesions (microcystic and macrocystic), and before considering therapeutic management. A biopsy, coupled to a blood sample, can also be used for molecular biology analyses, to search for activating mutations of the PIK3CA gene, particularly with LM integrating in a syndromic form (CLOVES or Klippel-Trenaunay syndrome) but also in certain isolated (or common) LMs. The spontaneous evolution of LMs, in particular microcystic forms, is often toward progressive aggravation, with an increase in the number of vesicles, thickening, increased oozing and bleeding, while pure macrocystic LMs may regress due to "natural sclerosis", i.e. fibrosis secondary to an inflammatory reorganization after common infantile infections. In case of voluminous LMs or syndromic forms, functional and psychological repercussions can be major, deteriorating the patient's quality of life. LMs must be treated by physicians integrated in multidisciplinary teams, and be personalized. Management is a life-long process that involves one or several of these therapies: conservative management, physical therapy (compression), sclerotherapy, surgery, drugs such as mTOR inhibitors (sirolimus), that has shown efficacy in decreasing the volume of LMs, and, more recently, PI3K-inhibitors in syndromic forms. Psychological and social support is necessary, taking into account the patient and his family.

Primary targeted medical therapy for management of bilateral head and neck lymphatic malformations in infants

OBJECTIVES

Patients born with bilateral head and neck lymphatic malformations (BHNLMs) often require multiple invasive treatments, including tracheostomy. We hypothesized that primary targeted medical therapy (pTMT) with diagnostic needle aspiration reduces the need for invasive therapy such as surgical resection and/or sclerotherapy.

METHODS

Retrospective case review was performed of infants with BHNLMs (Grade 2 or De Serres stage IV and V) treated only at our institution from 2000 to 2021. Patients were divided into two cohorts: those managed with pTMT and those managed with observation, sclerotherapy, or surgical intervention (non-pTMT). Data regarding interventions, clinical outcomes, morbidity, and mortality were analyzed with descriptive statistics.

RESULTS

Nine children with BHNLMs met inclusion criteria. Three (33%) were in the pTMT cohort and six (66%) were non-pTMT. Eight (89%) malformations were genotyped, and all demonstrated hotspot PIK3CA variants. All pTMT patients had sirolimus initiated in the first month of life and underwent needle aspiration of malformation cyst fluid for cell-free DNA samples. All pTMT patients tolerated medical therapy. For the non-pTMT cohort, primary treatment included none (deceased, n = 1, 17%), observation with needle aspiration (n = 1, 17%), surgical resection (n = 2, 33%), or combination surgery and sclerotherapy (n = 2, 33%). Intubation duration, intensive care and initial hospital length of stay were not different between cohorts. Four non-pTMT patients (67%) required tracheostomy, and two (33%) died prior to discharge. All pTMT patients survived and none required tracheostomy. Non-pTMT patients required a median of two invasive therapies prior to discharge (IQR 1-4) and a mean total of 13 over the course of their lifetime (IQR 1-16), compared to the pTMT group who did not require any lifetime invasive therapy, even after initial pTMT and discharge home.

CONCLUSION

This study compares patients with BHNLMs (Grade 2) treated with pTMT versus those treated with observation or invasive therapy. Patients treated with pTMT required no surgical or invasive procedural treatment of their malformations, no tracheostomy placement, no unplanned readmissions after discharge, and had no mortalities. Needle aspiration was useful as a therapeutic adjunct for cell-free DNA diagnosis of PIK3CA variants, which guided TMT.

Pediatric vascular anomalies with airway compromise

Vascular anomalies are rare lesions of diverse nature that may affect the head and neck region. Any mass in or around the upper airway has the potential to obstruct or compromise it. The absolute priority, before etiologic treatment, is the evaluation of the risk for the airway and its management. Prenatal diagnosis of an upper airway obstruction requires a planned delivery in a center having a specialized team experienced in managing a compromised feto-neonatal airway, and who could perform an ex-utero intrapartum treatment to secure the airway. Even after birth, the airway remains central in the patient's overall management. Signs and symptoms of airway compromise must be evaluated keeping in mind the specific requirements of infants and small children and being aware that rapid worsening may occur. The treatment is then tailored to the patient and his lesion with the goal of improving symptoms while avoiding treatment-related complications. Maintaining reasonable expectations by the patient and families are part of a successful management. Cure is achievable for small and localized lesions, but symptom relief and mitigation of functional, esthetic and psychological impairments is the goal for large and complex lesions. If a tracheotomy was required, decannulation is one of the primary management goals.

Liposuction-Like Sclerotherapy Technique for Microcystic Lymphatic Malformation

Background

The treatment for microcystic lymphatic malformation (LM) remains challenging. We describe the liposuction-like sclerotherapy technique, a new treatment for extensive microcystic LM.

Methods

LM data was retrospectively reviewed. This study included patients with a microcystic LM component treated by liposuction-like technique with bleomycin sclerotherapy.

Results

Between June 2016 and October 2019, 39 consecutive patients (male/female ratio: 21:18; mean age, 33.6 months; range: 5 months to 15 years) with microcystic LM were treated by liposuction-like sclerotherapy (LS-LS) technique. Fifty-six sessions of LS-LS were performed (mean of 1.44 sessions per patient; range: one to four sessions). Follow-up ranged 6-30 months (mean of 21 months). We observed no major complications. Transient minor complications included: postoperative noninfectious fever, vomiting, temporary skin edema, pigmentation, mild local depressions, and/or irregularities, and a small hyperpigmented scar at the incision. No postoperative infection, skin ulcer, or necrosis occurred. The patients’ symptoms were successfully resolved or stable. A sub-complete response and partial response were observed for 26 (76%) and 13 patients (33%), respectively.

Conclusion

The LS-LS technique for microcystic LMs is safe, feasible, and effective. This technique is an effective intervention with which it is possible to manage and potentially cure microcystic LM clinically.

Management of Macrocystic Lymphatic Malformation in the Cervicofacial Region: Ultrasound-Guided Iodine Tincture Cauterization Combined With Intralesional Negative Pressure

PURPOSE

The purpose of our study was to evaluate the efficacy and safety of ultrasound-guided iodine tincture cauterization combined with postoperative intralesional negative pressure in the management of cervicofacial cystic lymphatic malformation (cLM).

METHOD

From January 2019 to July 2021, indocyanine green lymphography was performed preoperatively to confirm the lymph inflow, and this treatment was administered in 71 patients with cervicofacial cLM in our center. All cases were evaluated by curative effects, treatment frequency, and adverse events. The duration of posttreatment follow-up was from 12 to 14 months.

RESULTS

Indocyanine green lymphography indicated at least one lymphatic inflow in each cLM lesion. Excellent resolution was observed in 87.3% of cases, and good improvement of the treated cLM occurred in 9.9% of cases, and 2 cases with fair outcomes required subsequent treatment. It is noteworthy that no case was treated more than 3 times. Some minor adverse effects, including localized itch and scar, were managed by symptomatic treatment.

CONCLUSIONS

Because of satisfactory outcomes and low treatment frequency, ultrasound-guided iodine tincture cauterization combined with intralesional negative pressure represents an efficacious, safe, and feasible method for the management of macro-cLM in the cervicofacial region.

Successful Sclerotherapy for Cervicofacial Macrocystic Lymphatic Malformations Using Polidocanol and Pingyangmycin Combined Foam Sclerosants

Background: Sclerotherapy is the first-line therapeutic method for lymphatic malformations (LMs). This retrospective cohort study evaluated the effectiveness and safety of a novel combined foam sclerosant: polidocanol and pingyangmycin foam (PPF), for treating cervicofacial macrocystic LMs. Methods and Results: From July 2018 to October 2020, 51 patients with cervicofacial macrocystic LMs were enrolled in this study. All patients received intralesional 3% polidocanol or PPF injections. The outcome was evaluated regarding demographic and clinical characteristics, degree of treatment response, and post-treatment complications. Overall, 16 patients (31.4%) underwent PPF sclerotherapy. All these patients (100%) showed remarkable reduction in lesion size within three sessions. Excellent responses were shown in 88.5% of these patients within three sessions, which is higher than single polidocanol sclerotherapy (80%). The average sessions (duration) of PPF sclerotherapy were 2.5, which was significantly shorter than the single foam sclerotherapy (p < 0.05). Treatment duration was significantly associated with age, lesion location, lesion size, and number of cysts (p < 0.05). No severe complications were noted in this study. Local or systemic complications, such as swelling and mild fever occurred but subsided without any specific treatment. Conclusions: PPF is a safe, and effective combined foam sclerosant for the treatment of cervicofacial macrocystic LMs. This combined foam can improve treatment response and reduce treatment duration compared with a single sclerosant. It can be broadly used if further large-scale clinical trials verify its efficacy and safety.

Acetylsalicylic acid suppression of the PI3K pathway as a novel medical therapy for head and neck lymphatic malformations

OBJECTIVES

Head and neck lymphatic malformations (HNLM) are caused by gain-of-function somatic mutations in PIK3CA. Acetylsalicylic acid (ASA/aspirin) is thought to limit growth in PIK3CA-mutated neoplasms through PI3K pathway suppression. We sought to determine if ASA could be beneficial for HNLM.

METHODS

Retrospective case series of patients (0-18 years) offered ASA (3-5 mg/kg/day) for HNLM treatment (2010-2018). Clinical and treatment characteristics, patient-reported symptom improvement, medication tolerance, compliance, and complications were recorded. Treatment response was determined by change in patient/caregiver-reported symptoms, or HNLM size [complete (resolved), partial (decreased), or stable].

RESULTS

Fifty-three patients were offered ASA, 23 (43%) accepted (median age 10 years, IQR 6-14). Compared to patients who declined, patients receiving ASA were more likely to have extensive malformations: ex-utero intrapartum treatment procedure, bilateral malformations, oral cavity location, ≥2 invasive treatments, or tracheotomy (p < 0.05). All patients with tissue available had PIK3CA mutations (13/23). Treatment indications included oral pain/blebs (12, 52%), recurrent pain/swelling (6, 26%), or sudden/persistent swelling (5, 22%). Treatment plan was commonly one 81 mg tablet daily (19, 83%) for 3-12 months (8, 42%). Therapeutic adherence was reported by 18 patients (78%). Symptoms improved in 18 patients [78%; decreased pain (9, 39%) and swelling (8, 35%)]. Treatment resulted in partial (14, 61%) or complete response (4, 17%). Three patients developed oral bleb bleeding, which resolved with medication discontinuation.

CONCLUSION

ASA seems to be a well-tolerated, low-risk medication for HNLM treatment. This pilot study suggests that it often improves symptoms and reduces HNLM size. Further prospective, randomized studies are warranted to comprehensively assess indications, safety, and efficacy.

LEVEL OF EVIDENCE

Level 4.

Oral lymphatic malformations: A multicenter study of 208 cases and literature review

BACKGROUND

To evaluate the frequency and analyze demographic and clinical characteristics of individuals with a histopathological diagnosis of oral lymphatic malformations (OLMs).

METHODS

A multicenter study was performed, collecting biopsy record data from a consortium of Brazilian Oral and Maxillofacial Pathology Centers. A review was also conducted to compare this data with cases already available in the literature.

RESULTS

This study retrieved 208 cases of OLM in the multicenter study and 1035 cases in the literature review. In both, OLMs affected male and female individuals equally, with the most affected site being the tongue. Individuals ≥60 years of age were uncommonly affected. Symptomatic and larger lesions were more commonly reported in the literature review.

CONCLUSIONS

This study comprises the largest sample of OLMs to date. OLMs are rare conditions, without sex predilection. The elderly proved to be less frequently affected, and the tongue is the most commonly affected site.

Lymphatic and Mixed Malformations

Lymphatic and mixed malformations are rare and variable in presentation. They arise due to errors in vascular and lymphatic formation during early embryonic development. This leads to persistent infiltration of lymph fluid into soft tissues and causes a locally invasive mass with pathologic sequelae. Departing from historically descriptive terminology, such as "cystic hygroma," lymphatic malformations are now categorized as macrocystic, microcystic, or mixed lesions, based on size. Advances in imaging modalities, such as ultrasonography and magnetic resonance imaging, have made accurate characterization of these lesions possible and ultimately allow for early diagnosis and implementation of appropriate treatment based on the morphology of the lymphatic malformation. Management of lymphatic malformations can be quite challenging, and a multidisciplinary approach is most effective for optimum aesthetic and functional outcomes. New discoveries in the molecular biology of lymphatic malformations have provided treatment targets and established a role for pharmacotherapy. Sclerotherapy, laser, and radiofrequency ablation have all proven to be effective as minimally invasive treatment options for lymphatic malformations. Surgical intervention has a role in the treatment of focal lesions recalcitrant to these less invasive techniques. Operative planning is dictated by clinical goals, size, anatomic location, characteristics, and extent of infiltration.

Active Observation as an Alternative to Invasive Treatments for Pediatric Head and Neck Lymphatic Malformations

OBJECTIVES

An increasing number of treatment modalities for lymphatic malformations are being described, complicating therapeutic decisions. Understanding lymphatic malformation natural history is essential. We describe management of head and neck lymphatic malformations where decisions primarily addressed lesion-induced functional compromise (ie, breathing, swallowing) to identify factors associated with invasive treatment and active observation. We hypothesize that non-function threatening malformations can be observed.

STUDY DESIGN

Retrospective case series.

METHODS

Retrospective case series of consecutive head and neck lymphatic malformation patients (2000-2017) with over 2 years of follow-up. Patient characteristics were summarized and associations with invasive treatment (surgery or sclerotherapy) tested using Fisher's exact. In observed patients, factors associated with spontaneous regression were assessed with Fisher's exact test.

RESULTS

Of 191 patients, 101 (53%) were male, 97 (51%) Caucasian, and 98 (51.3%) younger than 3 months. Malformations were de Serres I-III 167 (87%), or IV-V 24 (12%), and commonly located in the neck (101, 53%), or oral cavity (36, 19%). Initial treatments included observation (65, 34%) or invasive treatments such as primary surgery (80, 42%), staged surgery (25, 13%), or primary sclerotherapy (9, 5%). Of 65 initially observed malformations, 8 (12%) subsequently had invasive treatment, 36 (58%) had spontaneous regression, and 21 (32%) elected for no invasive therapy. Spontaneous regression was associated with location in the lateral neck (P = .003) and macrocystic malformations (P = .017).

CONCLUSION

Head and neck lymphatic malformation treatment selection can be individualized after stratifying by stage, presence of functional compromise, and consideration of natural history. Recognizing the spectrum of severity is essential in evaluating efficacy of emerging treatments, as selected malformations may respond to observation.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1392-1397, 2021.

Lymphatic malformations

Lymphatic malformations are low-flow vascular malformations that arise due to errors in vascular development. Lymphatic malformations are benign and usually noted at birth or in the first few years of life. Lymphatic mass lesions are composed of varying size of cysts; this article focuses on discussion of cystic lymphatic malformations. Lymphatic malformations can occur throughout the body especially in lymphatic rich areas such as the cervical and axillary locations as well as the groin, trunk, retroperitoneum, extremities, abdominal or thoracic cavities. Treatment options vary based upon size of cysts and location. A multimodal and interdisciplinary approach is essential to care for patients with lymphatic malformations. Management options include observation, pharmacotherapy, sclerotherapy, and surgical procedures.

Surgical resection of macrocystic lymphatic malformations of the head and neck: Short and long-term outcomes

BACKGROUND

Controversy exists on management of lymphatic malformations, with schools of thought advocating for observation, surgery or sclerotherapy. This study sought to examine outcomes after surgical resection of pediatric cervicofacial macrocystic lymphatic malformations (MLM).

METHODS

Case series with planned data collection on pediatric patients with cervicofacial MLM who underwent surgical resection at a tertiary referral center for vascular anomalies from January 1995 to June 2016. For consistency in patient population analysis, patients who had pre-surgical sclerotherapy or had mixed or microcystic disease were excluded. The main outcome was complete response rate (CR) and long-term recurrence-free survival (RFS).

RESULTS

Sixty-three patients who underwent excision of MLM were included, 52.4% were female, 77.8% Caucasian. The majority had de Serres stage I-III (96.8%) affecting the neck (71.4%). Patients were discharged the same day (28.6%), or had a 1 day median length-of-stay (interquartile range (IQR) = 2). Surgical complications included seroma/hematoma (9.5%), transient nerve weakness (facial nerve, sympathetic chain, or phrenic nerve, 6.3%), and infection (1.6%). On long-term follow-up (median: 12 months, IQR 1-43 months), a single surgery achieved CR in 90.5% of patients. RFS was achieved in 86% of patients in our observation period of up to 15 years. Most patients requiring a second intervention failed within 6-months of initial procedure (4/5 patients, 90%); associated factors included bilaterality, advanced staging, and partial response at first-follow-up (p = 0.0051, 0.0051, and <0.0001, respectively).

CONCLUSIONS

Surgery is safe and effective as first line treatment for selected MLM. For stage I-III MLM CR and long-term RFS can be achieved with a single surgery. A direct and randomized comparison of treatment modalities is needed.

Endoscopy-assisted, transoral submucosal coblation for pediatric retropharyngeal lymphatic malformations

OBJECTIVE

Retropharyngeal lymphatic malformations (LMs) are uncommon congenital anomalies. Open surgery, sclerotherapy and various pharmaceutical agents have been described to manage these lesions. However, when such lesions involve the retropharyngeal space with evidence of airway compromise, none of the above aforementioned modalities has shown superior result without repeated imaging and procedures. We describe the use of radiofrequency ablation (Coblation) in an endoscopic-assisted, transoral approach as a one-off treatment for pediatric retropharyngeal lymphatic malformations.

METHODS

Six patients with retropharyngeal lymphatic malformations, presented with airway compromise, were treated with endoscopic-assisted, transoral submucosal coblation in our unit between April 2015 to August 2018. We retrospectively reviewed their medical records, imaging and endoscopic findings.

RESULTS

Five out of our six patients had LMs involving only the retropharyngeal space, who received the coblation as their sole treatment. One patient with extensive LMs involving multiple neck compartments received coblation to the retropharyngeal part as an adjunct procedure. The average operation time was 62.8 min, and the average intraoperative blood loss was 3.8 ml. All patients were safely extubated immediately after the surgery. None required admission to pediatric intensive care unit (PICU), nor prolonged dysphagia reported. They were observed for 2-5 days post operatively. The average follow up was 28 months (1-5 years) and none required re-operation to date.

CONCLUSIONS

We presented our approach and outcome of 6 children with endoscopic-assisted, transoral submucosal coblation to retropharyngeal lymphatic malformation. We believe it is a safe and effective primary treatment to these patients, and a possible adjunct to complex vascular malformation involving multiple sites.

Long-term symptom control following resection of cervical lymphatic malformations: a case series

Background

Previous literature has reported on the incidence of short-term complications following resection of cervical lymphatic malformations (LMs) in children, however no research has yet investigated the long-term symptomatic course in these patients. This study aims to provide families and providers with an understanding of expectations for long-term symptom control, specifically in association with subsequent upper respiratory infections (URIs).

Methods

A retrospective chart review produced a case series of patients who underwent resection of cervical LM at a pediatric tertiary care center between 2007 and 2016. Demographic data, disease characteristics, operative details, and postoperative care were evaluated. Telephone surveys were conducted to ascertain the course of postoperative symptoms at the surgical site.

Results

Forty-three patients responded to the telephone survey. Thirty-seven (86.0%) had at least one postoperative surgical site symptom during subsequent URIs, with 28 (65.1%) reporting redness, 34 (79.1%) reporting swelling, and 18 (41.9%) reporting pain. Patients who experienced any of these symptoms universally indicated that they developed soon after the surgical resection, and over half reported that they improved over time. Postoperative seroma was associated with swelling during subsequent URIs (p = 0.04). Patients age 7 or were greater were more likely than those under 7 to report pain with URIs (p = 0.006). All 8 patients with drain placement for at least 2 days reported swelling during subsequent URIs. The incidence of the queried symptoms did not vary significantly based on sex, stage, histology, surgical subsite, or presence of residual disease.

Conclusion

While preoperative symptoms associated with cervical LMs are also frequently encountered postoperatively, particularly in some patient subgroups, improvement over time should be expected.

Level of evidence

4

Percutaneous sclerotherapy with gelified ethanol of low-flow vascular malformations of the head and neck region: preliminary results

PURPOSE

We aimed to evaluate the safety and effectiveness of percutaneous sclerotherapy using gelified ethanol in patients with low-flow malformations (LFMs).

METHODS

A retrospective study was performed, analyzing treatment and outcome data of 6 patients that presented with 7 LFMs (3 lymphatic and 3 venous). Median diameter of LFMs was 6 cm (interquartile range [IQR], 4.5-8.5 cm). Data regarding pain, functional and/or cosmetic issues were assessed. Diagnosis was performed clinically and confirmed by Doppler ultrasound, while extension of disease was assessed by magnetic resonance imaging (MRI). Percutaneous puncture was performed with 23G needle directly or with ultrasound guidance. All the LFMs were treated with gelified ethanol injection. The median volume injected per treatment session was 4.4 mL.

RESULTS

Technical and clinical success were obtained in all cases. No recurrences were recorded during a median follow up of 17 months (IQR, 12-19 months). Among the 6 patients, 5 had complete relief (83%) and one showed improvement of symptoms. The median VAS score was 7 (IQR, 6-7.5) before and 0 (IQR, 0-0) after treatment. All patients had functional and esthetic improvement (100%). Four patients (66.7%) revealed very good acceptance and two patients (33.3%) good acceptance. No major complications or systemic side effects were observed.

CONCLUSION

Gelified ethanol percutaneous sclerotherapy was easy to handle, well-tolerated, safe and effective in the short-term follow-up. Longer follow-up of efficacy is mandatory for further conclusions.

American Thoracic Society 2019 Pediatric Core Curriculum

The American Thoracic Society Pediatric Core Curriculum updates clinicians annually in pediatric pulmonary disease in a 3 to 4 year recurring cycle of topics. The 2019 course was presented in May during the Annual International Conference. An American Board of Pediatrics Maintenance of Certification module and a continuing medical education exercise covering the contents of the Core Curriculum can be accessed online at www.thoracic.org.

Genotype correlates with clinical severity in PIK3CA-associated lymphatic malformations

Lymphatic malformations (LMs) are congenital, nonneoplastic vascular malformations associated with postzygotic activating PIK3CA mutations. The mutation spectrum within LMs is narrow, with the majority having 1 of 3 hotspot mutations. Despite this relative genetic homogeneity, clinical presentations differ dramatically. We used molecular inversion probes and droplet digital polymerase chain reaction to perform deep, targeted sequencing of PIK3CA in 271 affected and unaffected tissue samples from 81 individuals with isolated LMs and retrospectively collected clinical data. Pathogenic PIK3CA mutations were identified in affected LM tissue in 64 individuals (79%) with isolated LMs, with variant allele fractions (VAFs) ranging from 0.1% to 13%. Initial analyses revealed no correlation between VAF and phenotype variables. Recognizing that different mutations activate PI3K to varying degrees, we developed a metric, the genotype-adjusted VAF (GVAF), to account for differences in mutation strength, and found significantly higher GVAFs in LMs with more severe clinical characteristics including orofacial location or microcystic structure. In addition to providing insight into LM pathogenesis, we believe GVAF may have broad applicability for genotype-phenotype analyses in mosaic disorders.

Common (Cystic) Lymphatic Malformations: Current Knowledge and Management

The approach to treating common (cystic) lymphatic malformations (LMs) has evolved significantly over the last decade due to clinical research and recent developments in molecular biology. Surgery, sclerosing agents, and medical drugs with specific targets for biological therapy have been reported for the management of LMs. We will discuss the importance to standardize the location and imaging characterization of LMs to improve the knowledge about the outcome of the different therapeutic options. Our goal is to help the reader understand the different options for the management of LMs with the balance between risk and benefit for the patients.

Genetics of vascular malformation and therapeutic implications

PURPOSE OF REVIEW

Vascular malformations (VaMs) are a consequence of disrupted morphogenesis that may involve arterial, capillary, venous, or lymphatic endothelium alone or in a combination. VaMs can have serious health impacts, leading to life-threatening conditions sometimes. Genetic mutations affecting proliferation, migration, adhesion, differentiation, and survival of endothelial cells, as well as integrity of extracellular matrix are believed to be the pathogenesis of these disorders. Here, we present an updated review of genetic mutations and potential therapeutic targets for VaMs.

RECENT FINDINGS

Increased number of genetic mutations have been discovered in vascular anomalies via targeted deep sequencing. When a genetic defect is identified, it often presents in only a small percentage of cells within the malformation. In addition, mutations within the same gene may result in different clinical phenotypes. Management of VaMs can be challenging depending on the severity and functional impairment associated. There are no standard treatment algorithms available to date for VaMs, therefore the disorder has significant unmet clinical needs. Currently, the focus of therapeutic development is to target constitutively activated intracellular signaling pathways resulted from genetic mutations.

SUMMARY

Knowledge about the genetic mutations and altered signaling pathways related to VaMs have improved our understanding about the pathogenesis of vascular anomalies and provided insights to the development of new targeted therapies.

HIF-1α contributes to tube malformation of human lymphatic endothelial cells by upregulating VEGFR-3

Hypoxia-inducible factor-1α (HIF-1α) is upregulated in various tumors and associated with lymphangiogenesis and angiogenesis during tumor development and metastasis. However, the role of HIF-1α in cystic lymphatic malformations (cLM) remains unclear. In the present study, expression of HIF-1α and vascular endothelial growth factor receptor 3 (VEGFR-3) was evaluated in 20 pairs of cLM specimens from patients who accepted curative surgery at Children’s Hospital of Nanjing Medical University (Nanjing, China). Additionally, a stable HIF-1α-overexpressing human lymphatic endothelial cell (HLEC) line was established. Overexpression and silencing of HIF-1α were used to investigate the biological role in colony formation, migration and lymphatic tube formation. HIF-1α and VEGFR-3 were upregulated in cLM specimens compared with adjacent normal tissues. In addition, HIF-1α effectively induced HLEC colony formation and migration. Furthermore, lymphatic malformation of HLECs was promoted in vitro by overexpression of HIF-1α. HIF-1α overexpression upregulated VEGFR-3 during lymphangiogenesis. Additionally, expression of lymphatic endothelial markers prospero homeobox protein 1 and lymphatic vessel endothelial hyaluronan receptor 1 increased significantly during lymphatic tube malformation. The presented data demonstrated that HIF-1α overexpression in HLECs promoted colony formation, migration and tube malformation via upregulation of VEGFR-3. These findings may assist in the development of HIF-1α-targeted cLM therapeutics in the future.

Medical Management of Vascular Anomalies

PURPOSE OF REVIEW

This chapter will summarize the most recent literature regarding the current state of medical treatment for vascular anomalies.

RECENT FINDINGS

Research into the biology of these anomalies has strengthened our understanding of each anomaly and has helped to pave the way for more tailored treatment options involving molecular and/or genetic targets.

SUMMARY

While there is still a role for surgical intervention, medical therapies that target the etiology of vascular anomalies may represent an alternative or adjunctive approach in the management of these lesions.