Cystic Hygroma: A Preliminary Genetic Study and a Short Review from the Literature

Single-cell RNA sequencing reveals cellular and molecular landscape of fetal cystic hygroma

BACKGROUND

The molecular mechanism of fetal cystic hygroma (CH) is still unclear, and no study has previously reported the transcriptome changes of single cells in CH. In this study, single-cell transcriptome sequencing (scRNA-seq) was used to investigate the characteristics of cell subsets in the lesion tissues of CH patients.

METHODS

Lymphoid tissue collected from CH patients and control donors for scRNA-seq analysis. Differentially expressed gene enrichment in major cell subpopulations as well as cell-cell communication were analyzed. At the same time, the expression and interactions of important VEGF signaling pathway molecules were analyzed, and potential transcription factors that could bind to KDR (VEGFR2) were predicted.

RESULTS

The results of scRNA-seq showed that fibroblasts accounted for the largest proportion in the lymphatic lesions of CH patients. There was a significant increase in the proportion of lymphatic endothelial cell subsets between the cases and controls. The VEGF signaling pathway is enriched in lymphatic endothelial cells and participates in the regulation of cell-cell communication between lymphatic endothelial cells and other cells. The key regulatory gene KDR in the VEGF signaling pathway is highly expressed in CH patients and interacts with other differentially expressed EDN1, TAGLN, and CLDN5 Finally, we found that STAT1 could bind to the KDR promoter region, which may play an important role in promoting KDR up-regulation.

CONCLUSION

Our comprehensive delineation of the cellular composition in tumor tissues of CH patients using single-cell RNA-sequencing identified the enrichment of lymphatic endothelial cells in CH and highlighted the activation of the VEGF signaling pathway in lymphoid endothelial cells as a potential modulator. The molecular and cellular pathogenesis of fetal cystic hygroma (CH) remains largely unknown. This study examined the distribution and gene expression signature of each cell subpopulation and the possible role of VEGF signaling in lymphatic endothelial cells in regulating the progression of CH by single-cell transcriptome sequencing. The enrichment of lymphatic endothelial cells in CH and the activation of the VEGF signaling pathway in lymphatic endothelial cells provide some clues to the pathogenesis of CH from the perspective of cell subpopulations.

Outcome of Sclerotherapy in a Preterm Infant with a Giant Fetal Neck Lymphatic Malformation: A Case Report

Introduction

Lymphatic malformation (LM), most commonly present in the neck area, is benign vascular malformations of the lymphatic system. In an infant, however, LM poses a high risk of adverse outcomes.

Case Presentation

We present a case with a giant fetal LM. Through ultrasonography, at 23+ weeks of gestation, a septate cystic mass 7.2×6.5×6.3 cm in size was found on the right side of the fetus's neck. After extensive counseling by the multidisciplinary team, the parents chose to continue the pregnancy. Severe fetal tracheal compression was observed at 29 weeks by magnetic resonance imaging (MRI). At 31 weeks and 5 days, owing to suspected fetal distress, an emergency cesarean section was performed and a male baby weighing 1720 g was delivered. The mass was 10×16×8 cm in size and ex utero intrapartum treatment (EXIT) was implemented. Due to progressive growth of the mass secondary to intralesional bleeding, an intralesional injection of bleomycin was administered three days later. This injection was repeated at the age of 1 month and 8 days. The baby was followed up and, by a year after his birth, LM had disappeared. The baby has since been in good health.

Conclusion

Accurate prenatal diagnosis and regular monitoring of a fetus with LM may improve prognosis. It is essential to have a trained multidisciplinary team to evaluate the condition of the fetus and the neonate and to provide treatment based on the evaluation. Our experience with intralesional bleomycin injection for the treatment of a giant fetal neck LM in a preterm infant had a favorable outcome. Long-term follow-up by a multidisciplinary team is needed in such cases.

Rare case of inguinal cystic lymphangioma diagnosed and treated in elderly patient

Cystic lymphangioma develops due to the interruption of lymphatic-venous connections during embryogenesis, leading to the formation of a cystic lesion containing lymph. These lesions fall under the ISSVA classification of vascular malformations. The first documented case dates back to 1828, with further elucidation provided by Sabin in 1909 and 1919. Cervicofacial region is the most common site, often showing early-stage symptoms. Inguinal location is rare, but if complications arise, it may present as a strangulated inguinal hernia. The tumor's severity lies in its compression and invasion of the aerodigestive tract and adjacent organs. Diagnosis relies on imaging techniques such as ultrasound and computed tomography, which help determine the mass's nature, boundaries, and relationship with neighboring structures. Asymptomatic lesions are generally monitored, while symptomatic ones require complete surgical excision to minimize the risk of recurrence. At Cheikh Khalifa University Hospital, we present a case highlighting our urology department's experience in diagnosis, patient care, and surgical treatment.

Beyond schwannomas and neurofibromas: a radiological and histopathological review of lesser-known benign lesions that arise in association with peripheral nerves

Peripheral nerve sheath tumors comprise a significant percentage of both benign and malignant soft tissue tumors. The vast majority of these lesions are schwannomas and neurofibromas, which most radiologists are familiar with including the well-described multimodality imaging features. However, numerous additional often under-recognized benign entities associated with nerves exist. These rarer entities are becoming increasingly encountered with the proliferation of cross-sectional imaging, particularly magnetic resonance imaging (MRI). It is important for the radiologist to have a basic understanding of these entities as many have near-pathognomonic MR imaging features as well as specific clinical presentations that when interpreted in concert, often allows for a limited differential or single best diagnosis. The ability to provide a prospective, pre-intervention diagnosis based solely on imaging and clinical presentation is crucial as several of these entities are "do not touch" lesions, for which even a biopsy may have deleterious consequences. To our knowledge, the majority of these benign entities associated with nerves have only been described in scattered case reports or small case series. Therefore, the aim of this article is to provide a radiopathologic comprehensive review of these benign entities that arise in association with nerves with a focus on characteristic MRI features, unique histopathologic findings, and entity specific clinical exam findings/presentation.

A Pain in the Neck: Lessons Learnt from Genetic Testing in Fetuses Detected with Nuchal Fluid Collections, Increased Nuchal Translucency versus Cystic Hygroma-Systematic Review of the Literature, Meta-Analysis and Case Series

Fetal Nuchal fluid collections can manifest with two distinct presentations attributable to the same phenotypic spectrum: increased nuchal translucency (iNT) and cystic hygroma. The prenatal detection of these findings should prompt an accurate assessment through genetic counseling and testing, including karyotype, chromosomal microarray analysis (CMA) and multigene RASopathy panel. We performed a systematic review of the literature and meta-analysis, to calculate diagnostic yields of genetic testing in fetuses with iNT and cystic hygroma. We compared the results with a cohort of 96 fetuses with these isolated findings. Fetuses with isolated NT ≥ 2.5 mm showed karyotype anomalies in 22.76% of cases and CMA presented an incremental detection rate of 2.35%. Fetuses with isolated NT ≥ 3 mm presented aneuploidies in 14.36% of cases and CMA had an incremental detection rate of 3.89%. When the isolated NT measured at least 3.5 mm the diagnostic yield of karyotyping was 34.35%, the incremental CMA detection rate was 4.1%, the incremental diagnostic rate of the RASopathy panel was 1.44% and it was 2.44% for exome sequencing. Interestingly, CMA presents a considerable diagnostic yield in the group of fetuses with NT ≥ 3.5 mm. Similarly, exome sequencing appears to show promising results and could be considered after a negative CMA result.

Mesenteric cysts, lymphatic leak, and cerebral cavernous malformation in a proband with KRIT1-related disease

Cerebral cavernous malformations (CCMs) of the central nervous system arise sporadically or secondary to genomic variation. Established genetic etiologies include deleterious variants in KRIT1 (CCM1), malcavernin (CCM2), and PDCD10 (CCM3). KRIT1-related disease has not been described in conjunction with lymphatic defects, although lymphatic defects with abnormal endothelial cell junctions have been observed in mice deficient in HEG1-KRIT1 signaling. We report a proband with CCMs, multiple chylous mesenteric cysts, and chylous ascites with leaky lymphatic vasculature. Clinical short-read exome sequencing detected a disease-associated KRIT1 variant (NM_194456.1:c.[1927C>T];[=], p.(Gln643*)). We postulate an expansion of KRIT1-related disease to include lymphatic malformations and lymphatic endothelial dysfunction.

Phenotypic and Genomic Analysis of Cystic Hygroma in Pigs

Cystic hygroma is a malformation of the lymphatic and vascular system and is recognized as a benign congenital tumor that affects humans and animals in the perinatal period. This congeni-tal disorder is rarely described in animals, and until today, cystic hygroma in pigs has not been described in the literature. In a purebred Piètrain litter with twelve live-born piglets, cystic hy-groma was noticed on the rump of two male pigs within the first week of life. In addition, a third case of a crossbred weaner (Large White × Landrace) was detected during a herd examina-tion. To rule out common differential diagnoses, e.g., abscess or hematoma, further clinical and pathological investigations were conducted. During clinical examination, a painless and soft mass, which was compressible, was detected on the rump of all affected animals. The ultra-sonographic examination revealed a fluid-filled and cavernous subcutaneous structure. In addi-tion, a puncture of the cyst was conducted, revealing a serosanguinous fluid with negative bacte-riological culture. In all cases, a necropsy was performed, showing that the animals had fluid-filled cysts lined by well-differentiated lymphatic endothelium. Based on the clinicopathological examination, cystic hygroma was diagnosed. Furthermore, SNP array genotyping and whole-genome sequencing was performed and provided no evidence for a chromosomal disorder. In the Piètrain family, several genome regions were homozygous in both affected piglets. None-theless, a dominant acting de novo germline variant could not be ruled out, and therefore differ-ent filtering strategies were used to find pathogenic variants. The herein presented lists of pri-vate variants after filtering against hundreds of control genomes provide no plausible candidate and no shared variants among the two sequenced cases. Therefore, further studies are needed to evaluate possible genetic etiology. In general, systematic surveillance is needed to identify ge-netic defects as early as possible and to avoid the occurrence of losses in the pig population.

Solitary hepatic lymphangioma mimicking liver malignancy: A case report and literature review

BACKGROUND

Hepatic lymphangioma, a malformation of the liver lymphatic system, is a rare benign neoplasm and usually coexists with other visceral lymphangiomas. Solitary hepatic lymphangioma is much more rarely seen and could cause a clinical misinterpretation as malignancy.

CASE SUMMARY

A 50-year-old woman with a liver mass of approximately 3.5 cm was initially diagnosed with hepatocellular carcinoma given the risk factors for liver cancer that she presented with, including Schistosome japonicum infection and jaundice, and also together with imaging results, which showed the mass enhanced quickly in the arterial phase and faded fast in the venous phase. The patient did not have the surgery first but received three rounds of transarterial chemoembolization because of her anxiety and fears for operation. Finally, the patient underwent laparoscopic liver segment 4b resection and cholecystectomy and was discharged from the hospital only 10 d after the operation. The pathological examination indicated the mass as hepatic lymphangioma. The patient has been followed up for 30 mo without recurrence. To raise the awareness of this misdiagnosed case and to better diagnose and treat this rare disease in future, we reviewed the published literature of solitary hepatic lymphangioma for its clinical symptoms, imaging presentation, operative techniques, histology features and prognosis.

CONCLUSION

Solitary hepatic lymphangioma mimicking malignancy makes diagnosis difficult. Complete surgical resection is the first choice to treat solitary hepatic lymphangioma.