Mesenteric and omental lymphatic malformations in children: seven-year surgical experience from two centers in China.

PURPOSE: To compare the clinical characteristics, surgical management and prognosis of mesenteric lymphatic malformations (ML) and omental lymphatic malformations (OL) in children. METHODS: This retrospective study included 148 ML patients and 53 OL patients who underwent surgical treatment at two centers between January 2016 and December 2022. Details about the patients' clinical characteristics, cyst characteristics, preoperative complications, surgical methods, and prognosis were retrieved and compared. RESULTS: No significant differences in sex ratio, prenatal diagnosis, or age of diagnosis were noted between ML and OL patients. Vomiting was more common in ML patients than in OL patients (46.6% vs. 22.6%, P = 0.002), but OL patients were more likely to be misdiagnosed (35.8% vs. 18.9%, P = 0.012). The size of the cysts in OL patients was significantly larger than that in ML patients (14.0 [4.0-30.0] vs. 10.0 [2.0-50.0] cm, P<0.001), and cysts with turbid fluid were more common in OL patients (38.0% vs. 20.6%, P<0.001). More OL patients than ML patients had preoperative hemorrhage or infection of cysts (41.5% vs. 31.8%, P<0.016). Cyst excision was performed in 137 (92.6%) ML patients and 51 (96.2%) OL patients, and the incidence of postoperative complications was lower (12.6% vs. 4.2%, P = 0.165) among OL patients. The main postoperative complications included adhesive ileus and recurrence of cysts. Additionally, more OL patients than ML patients were treated with laparoscopic surgery (69.8% vs. 39.2%, P<0.001). CONCLUSIONS: There were differences in clinical characteristics, cyst characteristics and preoperative complications between ML and OL patients. Cyst excision was the most common surgical method that was used to treat both ML and OL patients, and laparoscopic surgery could be a feasible surgical approach for treating OL patients with a good prognosis. TRIAL REGISTRATION: Retrospectively registered.

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.

Interventional treatment of refractory non-traumatic chylous effusions in patients with lymphoproliferative disorders.

To report results of interventional treatment of refractory non-traumatic abdomino-thoracic chylous effusions in patients with lymphoproliferative disorders. 17 patients (10 male; mean age 66.7 years) with lymphoproliferative disorders suffered from non-traumatic chylous effusions (chylothorax n = 11, chylous ascites n = 3, combined abdomino-thoracic effusion n = 3) refractory to chemotherapy and conservative therapy. All underwent x-ray lymphangiography with iodized-oil to evaluate for and at the same time treat lymphatic abnormalities (leakage, chylo-lymphatic reflux with/without obstruction of central drainage). In patients with identifiable active leakage additional lymph-vessel embolization was performed. Resolution of effusions was deemed as clinical success. Lymphangiography showed reflux in 8/17 (47%), leakage in 2/17 (11.8%), combined leakage and reflux in 3/17 (17.6%), lymphatic obstruction in 2/17 (11.8%) and normal findings in 2/17 cases (11.8%). 12/17 patients (70.6%) were treated by lymphangiography alone; 5/17 (29.4%) with leakage received additional embolization (all technically successful). Effusions resolved in 15/17 cases (88.2%); 10/12 (83.3%) resolved after lymphangiography alone and in 5/5 patients (100%) after embolization. Time-to-resolution of leakage was significantly shorter after embolization (within one day in all cases) than lymphangiography (median 9 [range 4-30] days; p = 0.001). There was no recurrence of symptoms or post-interventional complications during follow-up (median 445 [40-1555] days). Interventional-radiological treatment of refractory, non-traumatic lymphoma-induced chylous effusions is safe and effective. Lymphangiography identifies lymphatic abnormalities in the majority of patients and leads to resolution of effusions in > 80% of cases. Active leakage is found in only a third of patients and can be managed by additional embolization.

Syndromic and single gene disorders associated with fetal pleural effusion (I): Noonan syndrome, RASopathy and congenital lymphatic anomalies.

Fetal pleural effusion has been reported to be associated with chromosomal abnormalities, genetic syndromes, obstructive uropathy, lymphatic vessel abnormalities such as Noonan syndrome, RASopathy and congenital lymphatic anomalies, thoracic cavity defects, Rh or ABO incompatibility, non-immune hydrops fetalis, infections, congenital cardiac anomalies, metabolic diseases and hematologic diseases such as α-thalassemia. This review provides an overview of syndromic and single gene disorders associated with fetal pleural effusion that is useful for genetic counseling and fetal therapy at prenatal diagnosis of fetal pleural effusion.

Lymphatic malformations: mechanistic insights and evolving therapeutic frontiers.

The lymphatic vascular system is gaining recognition for its multifaceted role and broad pathological significance. Once perceived as a mere conduit for interstitial fluid and immune cell transport, recent research has unveiled its active involvement in critical physiological processes and common diseases, including inflammation, autoimmune diseases, and atherosclerosis. Consequently, abnormal development or functionality of lymphatic vessels can result in serious health complications. Here, we discuss lymphatic malformations (LMs), which are localized lesions that manifest as fluid-filled cysts or extensive infiltrative lymphatic vessel overgrowth, often associated with debilitating, even life-threatening, consequences. Genetic causes of LMs have been uncovered, and several promising drug-based therapies are currently under investigation and will be discussed.

Imaging manifestations of head and neck lymphatic malformations: A single-center experience of 170 surgical cases.

OBJECTIVES: To discuss the imaging manifestations and the utility of preoperative ultrasonography (US), contrast-enhanced computed tomography (CE-CT) and contrast enhanced magnetic resonance imaging (CE-MRI) in diagnosing the pediatric head and neck lymphatic malformations (HNLMs). METHODS: We performed a retrospective review of 170 children who were referred to our hospital in the past 9 years for the treatment of HNLMs. RESULTS: The diagnostic rates of US, CE-CT and CE-MRI were 93.0% (146/157), 94.7% (143/151) and 100% (45/45), respectively. As in multilocular cases, intracystic septa detection rate was 91.5% (130/142), 50.4% (68/135) and 88.1% (37/42), and which had a statistical difference (χ2 = 25.8131, p < 0.05). US showed capsule contents anechoic in 51.0% (80/157) cases, hypoechoic or mixed echoic in 49.0% (77/157) cases, and flocculent or dotted echo floating in 36.9% (58/157) cases. CT showed low density of the capsule contents without enhancement in 69.5% (105/151) cases and mixed density with enhancement in 30.4% (46/151) cases. Liquid-liquid levers were seen in 8.6% (13/151) cases. MRI showed T1WI high signal and T2WI low signal of the capsule contents without enhancement in 28.9% (13/45) cases and mixed density in 71.1% (32/45) cases. Liquid-liquid levers were seen in 46.7% (21/45) cases. There were statistically significant differences between pure HNLMs and intracystic hemorrhage in capsule content (echo, density, signal), enhancement, and liquid-liquid lever (all p < 0.05). Among US, CE-CT and CE-MRI, intracystic hemorrhage diagnostic accuracy had a statistical difference (χ2 = 25.4152, p < 0.05). CONCLUSIONS: For clinical diagnosis and evaluation of HNLMs, we suggest that US combined with CE-CT for acute cases, and for stable cases, US combined with CE-MRI.

Efficacy of Bleomycin-Lauromacrogol Foam in Pediatric Macrocystic Lymphatic Malformations With and Without Intracapsular Hemorrhage.

BACKGROUND: Sclerotherapy is purportedly less effective in patients with hemorrhagic than with non-hemorrhagic lymphatic malformations (LMs). We aimed to compare the efficacy of bleomycin-lauromacrogol foam (BLF) sclerotherapy in the treatment of macrocystic LMs with and without intralesional hemorrhage. METHODS: Fifty-five children with macrocystic LMs admitted to the Pediatric Surgery Department were retrospectively included. The patients were allocated into a hemorrhage group (23 cases) or a non-hemorrhage group (32 cases) based on the occurrence of an intracapsular hemorrhage. The diagnosis was confirmed by physical examination, color ultrasound, magnetic resonance imaging, and puncture findings. BLF was injected into the capsule after draining the cystic fluid under color ultrasound guidance. Patients whose lesions were unchanged or showed minor change after 1 month were treated again using the same method. Changes in lesion size and the number of treatments were recorded. Effectiveness was classified as excellent (volume reduction ≥90%), good (50%≤volume reduction<90%), or poor (volume reduction <50%). RESULTS: In the hemorrhage group, 17, 6, and 0 patients' outcomes were classified as excellent, good, and poor, respectively. The overall efficacy rate was 100%. In the non-hemorrhage group, 23, 7, and 2 patients' outcomes were classified as excellent, good, and poor, respectively. The overall efficacy rate was 93.8%. There was no significant difference in efficacy rate between groups (P = 0.767). CONCLUSIONS: BLF is an effective and safe treatment for macrocystic LMs with bleeding. The results were similar in patients with and without bleeding. LEVEL OF EVIDENCE: Treatment, Level III.

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.

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.

Malformación linfática quística gigante del hígado: dos casos pediátricos con diferente abordaje quirúrgico / Giant cystic lymphatic malformation of the liver: two pediatric cases with different surgical approach

Introducción. Las malformaciones linfáticas quísticas, también llamadas linfangiomas quísticos, aparecen muy raramente de forma aislada en el hígado. Casos clínicos. Se presentan dos pacientes femeninas de edad preescolar con marcada hepatomegalia, dependiente de lesiones quísticas multitabicadas, secundarias a malformación linfática quística gigante del hígado, que fueron tratadas en el Hospital Pediátrico Universitario William Soler, La Habana, Cuba. Resultados. En ambos casos el diagnóstico se apoyó en los estudios de imágenes, la laparoscopia y el análisis histopatológico. En un caso el tratamiento fue la hepatectomía derecha, mientras que en el otro se empleó la escleroterapia, ambas con evolución favorable. Conclusión. A pesar de su rareza, este diagnóstico no debe obviarse ante un paciente pediátrico con lesiones hepáticas quísticas. El tratamiento de elección es la resección quirúrgica, pero su indicación y envergadura debe valorarse de forma individualizada

Introduction. Cystic lymphatic malformations, also called cystic lymphangiomas, are very rarely found in the liver. Clinical cases. Two pediatric female preschool-age patients. presented with hepatomegaly due to multi-septated cystic lesions of the liver, who received treatment at Hospital Pediátrico Universitario William Soler, La Habana, Cuba. Results. We report two pediatric cases with giant cystic lymphatic malformation of the liver. In both cases, the diagnosis were based on imaging, laparoscopy and pathology. In one case the treatment was right hepatectomy, whereas in the other, sclerotherapy was performed, both with a favorable outcome. Conclusion. Despite its rarity, this diagnosis should be considered in pediatric patients with hepatic cystic lesions. The recommended treatment is surgical resection, but its indication and extent should be assessed individually for each patient.

Risk factors for sequelae after surgery for lymphatic malformations in children.

OBJECTIVE: The first-line treatment of lymphatic malformations (LMs) is pharmacological or interventional; however, surgery is still necessary in selected cases. Our aim was to identify factors associated with the occurrence of permanent postoperative complications. METHODS: This was a case series study of children operated on for LMs between 2001 and 2021 and followed-up in our institution. Patients who presented sequelae derived from surgical treatment (cases) and those who did not (controls) were compared. RESULTS: We included 112 children who underwent surgery for LMs in different centers. Forty-nine cases and 63 controls were included (58% male), with a mean age of 34 months. Patients younger than 1 year presented more complications than older children, 59% (n = 29/49) vs 41% (n = 24/49), respectively (P = .02). LMs were in the cervicofacial region in seven patients in the control group compared with 30 of the cases (P ≤ .001), with microcystic malformations the most associated with sequelae (n = 11/15; P = .019). Concerning permanent complications, 88% were neurological (n = 43/49), mainly peripheral facial palsy (n = 17). There was greater postoperative residual disease in controls compared with cases (65% vs 14%, respectively; P ≤ .0001). However, following a second procedure in the control group, there was no significant difference in long-term cure rates (P = .38). CONCLUSIONS: The risk of sequelae following surgery for LM increases significantly in patients younger than 12 months in cervicofacial and microcystic malformations. Because non-radical resections are associated with fewer complications and an optimal long-term cure rate, we consider that aggressive surgical approaches should be avoided if the absence of sequelae is not guaranteed.

Microcystic lymphatic malformations in Turner syndrome are due to somatic mosaicism of PIK3CA.

Turner syndrome (45,X) is caused by a complete or partial absence of a single X chromosome. Vascular malformations occur due to abnormal development of blood and/or lymphatic vessels. They arise from either somatic or germline pathogenic variants in the genes regulating growth and apoptosis of vascular channels. Aortic abnormalities are a common, known vascular anomaly of Turner syndrome. However, previous studies have described other vascular malformations as a rare feature of Turner syndrome and suggested that vascular abnormalities in individuals with Turner syndrome may be more generalized. In this study, we describe two individuals with co-occurrence of Turner syndrome and vascular malformations with a lymphatic component. In these individuals, genetic testing of the lesional tissue revealed a somatic pathogenic variant in PIK3CA-a known and common cause of lymphatic malformations. Based on this finding, we conclude that the vascular malformations presented here and likely those previously in the literature are not a rare part of the clinical spectrum of Turner syndrome, but rather a separate clinical entity that may or may not co-occur in individuals with Turner syndrome.

Sirolimus for Pediatric Cervicofacial Lymphatic Malformation: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study is a systematic review and meta-analysis of the efficacy and safety of sirolimus in the management of pediatric cervicofacial lymphatic malformations (LMs). DATA SOURCES: EMBASE, Medline, Scopus, and Cochrane databases were searched, along with the reference list of all included articles. REVIEW METHODS: The study protocol was registered with PROSPERO and a systematic literature search strategy was designed and conducted with the aid of a medical librarian. All studies including case reports were included, with pooled analysis of raw data. A meta-analysis was conducted of magnetic resonance imaging (MRI), clinical, and airway outcomes. RESULTS: Thirteen case series and five individual case reports were included. Meta-analysis showed 78% (95% CI 57%-94%) of 62 patients had a reduction in LM volume, on MRI criteria, by 20% or more, and 32% (95% CI 11%-57%) had a reduction of 50% or more. Further meta-analysis showed 97% (95% CI 88%-100%) of 78 patients reported some clinical improvement on sirolimus. Sirolimus may be of particular value in management of airway LMs; out of 27 tracheostomy-dependent patients, meta-analysis showed 33% (95% CI 1%-78%) were decannulated after starting sirolimus. Individual patient meta-analysis on 24 individuals showed a statistically significant better response to sirolimus when initiated under the age of 2 years. CONCLUSION: This review and meta-analysis support the efficacy of sirolimus in pediatric LMs of the head, neck, and airway. A large multi-center trial is needed to further explore its role and limitations. Laryngoscope, 134:2038-2047, 2024.

Lymphoscintigraphy Findings are Associated with Outcome in Children with Chylothorax After Cardiac Surgery.

Postoperative chylothorax in patients with congenital heart diseases (CHD) results in poor outcomes if anatomical and functional abnormalities of the lymphatic system are present. While these abnormalities are typically diagnosed by intranodal lymphangiography and dynamic contrast magnetic resonance lymphangiography, the usefulness of lymphoscintigraphy in these patients has not been evaluated. Between January 2019 and December 2021, 28 lymphoscintigraphies were performed in our institution for investigating prolonged pleural effusion after cardiac surgery. The images were assessed by three board-certified pediatric cardiologists retrospectively to determine the likelihood of a central lymphatic flow disorder. The likelihood was scored (range 1-3) based on structural abnormalities and congestive flow in the lymphatic system. Those scores were summed and the likelihood was categorized as low to intermediate (< 8 points) or high (8 or 9 points). Median age at lymphoscintigraphy was 129 days (IQR, 41-412 days), it was performed at a median of 22 days (IQR, 17-43) after surgery, and median score was 6 points (IQR, 4-7.5). Kendall's coefficient of concordance (0.867; p < 0.05) indicated high inter-rater reliability. Overall survival at 6 months after surgery was 92.5% in the low-to-intermediate group but 68.6% in the high group (p < 0.05), and duration of postoperative thoracic drainage was 27 and 58 days, respectively (p < 0.05). Lymphatic abnormalities detected by lymphoscintigraphy were associated with poorer outcomes. Lymphoscintigraphy was thought to be useful in assessing anatomic and functional lymphatic abnormalities, despite its minimal invasiveness.

A case series of fetal lymphatic malformations and a review of the literature.

Lymphatic malformations are rare benign developmental anomalies of the lymphatic system that can be diagnosed by prenatal ultrasound. Depending on their anatomical site and size, the lesions can cause a variety of aesthetic and functional deficits. Several treatment options are available, the most suitable is still under debate. The experience gained at our Centre and the review of the literature can be useful to improve prenatal counseling, that is challenging due to the heterogeneity of clinical presentation and treatment.

Generalized lymphatic anomaly in adult patients: An eminently radiological diagnosis.

Generalized lymphatic anomaly (GLA) is an uncommon congenital disease secondary to the proliferation of lymphatic vessels in any organ except the central nervous system. GLA has a wide spectrum of clinical and radiological presentations, among which osteolytic lesions are the most widespread, being the ribs the most commonly affected bone. GLA is diagnosed mainly in children and young adults; nevertheless, on rare occasions it can remain asymptomatic and be detected incidentally in older patients. We present an unusual case of GLA in an asymptomatic 54-year-old man who had atypically distributed, purely cystic bone lesions on CT; measuring the Hounsfield (HU) of these lesions enabled us to suspect GLA. This suspicion was confirmed with MRI, PET/CT, CT-guided fine-needle aspiration biopsy, and fluoroscopy-guided percutaneous vertebral biopsy. After surgical resection of one of the lesions, histologic study provided the definitive diagnosis.

Spectrum of lymphatic anomalies in patients with RASA1-related CM-AVM.

BACKGROUND: Capillary malformation-arteriovenous malformation (CM-AVM) is characterized by multifocal fast-flow capillary malformations, sometimes with arteriovenous malformations/fistulas, skeletal/soft tissue overgrowth, telangiectasias, or Bier spots. Lymphatic abnormalities are infrequently reported. We describe seven patients with CM-AVM and lymphatic anomalies. METHODS: Following IRB approval, we identified patients with CM-AVM and lymphatic anomalies seen at the Vascular Anomalies Center at Boston Children's Hospital from 2003 to 2023. We retrospectively reviewed records for clinical, genetic, laboratory, and imaging findings. RESULTS: We found seven patients with CM-AVM and lymphatic abnormalities. Five patients were diagnosed prenatally: four with pleural effusions (including one suspected chylothorax) and one with ascites. Pleural effusions resolved after neonatal drainage in three patients and fetal thoracentesis in the fourth; however, fluid rapidly reaccumulated in this fetus causing hydrops. Ascites resolved after neonatal paracentesis, recurred at 2 months, and spontaneously resolved at 5 years; magnetic resonance lymphangiography for recurrence at age 19 years suggested a central conducting lymphatic anomaly (CCLA), and at age 20 years a right spermatic cord/scrotal lymphatic malformation (LM) was detected. Chylous pericardial effusion presented in a sixth patient at 2 months and disappeared after pericardiocentesis. A seventh patient was diagnosed with a left lower extremity LM at 16 months. Six patients underwent genetic testing, and all had RASA1 mutation. RASA1 variant was novel in three patients (c.1495delinsCTACC, c.434_451delinsA, c.2648del), previously reported in two (c.2603+1G>A, c.475_476del), and unavailable in another. Median follow-up age was 5.8 years (4 months-20 years). CONCLUSION: CM-AVM may be associated with lymphatic anomalies, including pericardial/pleural effusions, ascites, CCLA, and LM.