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.

Cystic lymphangioma of the lesser omentum in a pregnant woman: a case report and review of the literature

Lymphangiomas are rare benign tumors which are generally seen in pediatric population and the etiopathogenesis has not yet been understood. They occasionally occur in the head and neck or axillary region with only 5% of them being located in the abdominal or mediastinal cavity. These tumors may be asymptomatic or may cause acute abdominal symptoms due to the location and extention. In the English literature, only 4 cases of lymphangioma were reported to have occurred in the pregnancy period. Herein, we report a case of cystic lymphangioma of the lesser omentum detected incidentally on the ultrasonogram of a 21 year-old, 26-week pregnant woman. The patient was followed up uneventfully during pregnancy. Caesarean section was performed due to transverse presentation of the fetus, and the tumor was completely resected during the same session. The patient is recurrence-free after 1 year of postoperative follow-up.

[Clinicopathologic features of fetal nuchal cystic hygroma: report of 40 cases]

OBJECTIVE

To study the pathogenesis, pathologic features and prognosis of fetal nuchal cystic hygroma.

METHODS

Forty autopsied cases of fetal nuchal cystic hygroma were collected during January 2003 to December 2012. The clinical history, pathologic changes and immunohistochemical (EnVision method) findings were reviewed, and the pathogenesis and pathologic characteristics were analyzed.

RESULTS

Of the 40 cases, 16 (40.0%) showed single malformation and 24 (60.0%) were associated with multiple malformations in other organs and/or systems.Nineteen cases were septated and 21 were not. The associated malformations occurred in the respiratory system, skeletal system and urinary system.In the cases of combined malformations of umbilical cord, 3 were single umbilical artery malformations and 1 was torsion and stricture of umbilical cord.Four cases had chromosomal analysis, and all were trisomy-21.

CONCLUSIONS

Fetal nuchal cystic hygroma is a rare disease. The etiology is unknown, but it is not neoplastic.Lymphangioma is divided into 3 types:capillary lymphangioma, cavernous lymphangioma and cystic hygroma according to their expansile growth pattern. The overall prognosis is determined by any co-existing chromosomal anomalies, associated malformations and the time of diagnosis of the cystic hygroma.

Primary retroperitoneal acinar cell cystadenoma

In this report, we describe a case of hitherto unreported primary retroperitoneal acinar cell cystadenoma that morphologically and immunophenotypically resembled pancreatic acinar cell cystadenoma. Pancreatic acinar cell cystadenoma is a very uncommon benign lesion characterized by acinar cell differentiation, the evidence of pancreatic exocrine enzyme production, and the absence of cellular atypia. Our case occurred in a 55-year-old woman presenting a 10-cm multilocular cystic lesion in the retroperitoneum thought to be a mucinous cystic neoplasm. At laparotomy, the cystic mass, which showed no connection with any organ, was completely resected with a clinical diagnosis of cystic lymphangioma. The diagnosis of retroperitoneal acinar cell cystadenoma was based on the recognition of morphological acinar differentiation, the immunohistochemical demonstration of the acinar marker trypsin, and the absence of cellular atypia. These peculiar features can be used in the differential diagnosis with all the other cystic lesions of the retroperitoneum.

Analysis of cytokine levels in human lymphangiomas

BACKGROUND

Different theories concerning the origin of lymphangiomas have been formulated but their precise pathogenesis is still unknown. This study aimed to analyze the levels of different cytokines in lymphangioma cyst fluids.

MATERIALS AND METHODS

Fluid aspirates from lymphangioma cysts of five patients were obtained. The intracystic levels of interleukin (IL)-6, IL-8, IL-2R and tumor necrosis factor alpha (TNFalpha) were determined in four cases before and one case after OK-432 administration using an immunometric assay.

RESULTS

Increased IL-6 levels were observed in all cases. Moreover, elevated IL-2R and TNFalpha levels were observed in three out of four and elevated IL-8 levels in two out of four untreated cases. There was a 25-fold increase in IL-6 after repeated OK-432 injections while IL-8, IL-2R and TNFalpha levels did not change significantly.

CONCLUSION

These findings suggest that cytokines may be involved in the pathogenesis of lymphangiomas.

[Cystic lymphangioma of the adrenal glands. Case report]

OBJECTIVE

Lymphangiomas are rare adrenal lesions, most of them asymptomatic.

METHODS

We report one case of adrenal lymphangioma in a 41-year-old female patient with elevated serum catecholamine levels.

RESULTS

Lymphangiomas are multicystic lesions covered by endothelium and with serous content, the differential diagnosis of which is mainly established with hemangioma and adenomatoid tumor.

CONCLUSIONS

Surgical treatment is indicated in big lesions and symptomatic cases, which are left asymptomatic after surgery.

[Splenic lymphangioma: clinicopathologic and immunohistochemical study of 18 cases and review of literature]

OBJECTIVE

To study the clinicopathologic features and differential diagnosis of splenic lymphangioma.

METHODS

Eighteen cases of splenic lymphangioma were retrieved from the pathology archives during the period between January 1990 to December 2005. The clinicopathologic features were analyzed. Immunohistochemical study was performed on the paraffin sections of 16 cases.

RESULTS

The age of the patients ranged from 9 to 72 years (median = 40 years). Thirteen patients were males and 5 were females. Clinically, the tumor could be asymptomatic or present with abdominal symptoms and hypersplenism. Follow-up information was available in 13 patients (72.2%) and the duration varied from 5 months to 15 years. All 13 patients had an uneventful clinical course, with no evidence of residual disease, local recurrence or metastasis. Gross examination showed splenic enlargement. The tumor appeared as cystic (8/18), solid (5/18) or honeycomb mass (5/18), either solitary (5/18) or multifocal (13/18). Histologically, splenic lymphangioma could be subclassified as cavernous (9/18), cystic (5/18) or mixed (4/18). Immunohistochemical study showed that the positivity rates for CD9 and D2-40 were 100% and 43.8% respectively.

CONCLUSIONS

Splenic lymphangioma is a rarely encountered entity that can be misdiagnosed as a splenic hemangioma. A definite diagnosis depends on pathologic examination.

Cystic lymphangioma of the pancreas: anatomoclinical, diagnostic and therapeutic considerations regarding three personal observations and review of the literature

Cystic lymphangioma is a very rare pathology and the pancreatic ones represent an exceptional report that must be considered in the differential diagnosis with others and more frequent cystic lesions of the pancreas. In this paper we describe three cases of cystic lymphangiomas of the pancreas observed in our Institute and we report on the literature review. Anatomopathological, clinical and therapeutics aspects of pancreatic cystic lymphangioma were analyzed for a better knowledge of this cystic lesion and to recognize some specific findings that could allow a preoperative diagnosis and, subsequently, a proper treatment.

Protein-loss into retroperitoneal lymphangioma: demonstration by lymphoscintigraphy and blood-pool scintigraphy with Tc-99m-human serum albumin

A rare, benign congenital lymphangioma has been reported to occur frequently in the neck and axilla, but rarely in the retroperitoneal space. We report a case of a retroperitoneal lymphangioma associated with hypoproteinemia caused by protein-loss into the tumor. In this case, lymphoscintigraphy with subcutaneously injected Tc-99m-human serum albumin (HSA) disclosed the communication between the tumor and the lymphatic system, and sequential abdominal scintigraphy with intravenously injected Tc-99m-HSA revealed the protein loss into the tumor. Abdominal scintigraphy with Tc-99m-HSA injected intravenously or subcutaneously is occasionally useful for determining the etiology of hypoproteinemia.

Biochemical analyses of mesenchymal fluid in early pregnancy

OBJECTIVE

Our purpose was to compare the biochemical composition of the fluid contained in pathologic and physiologic cavities in early pregnancy.

STUDY DESIGN

The level of urea, creatinine, electrolytes, enzymes, total protein, and alpha-fetoprotein and the affinity of alpha-fetoprotein for concanavalin A Sepharose was measured in samples of vesicular fluid from complete (n=2) and partial (n=1) mole, nuchal fluid (n=4), and cystic hygroma fluid (n=4). For comparison samples of maternal serum (n=32), amniotic fluid (n=32), coelomic fluid (n=15), and fetal blood (n=13) were obtained from normal pregnancies at 10 to 16 weeks' gestation.

RESULTS

Urea concentration was lower, whereas sodium, potassium, and total protein concentrations were higher in vesicular fluid than in amniotic and coelomic fluid. Urea, creatinine, sodium, potassium, chloride, and beta2-microglobulin concentrations did not vary between nuchal or cystic hygroma fluid and amniotic fluid or fetal serum. The concentration of total protein in nuchal and hygroma fluid was significantly lower than in fetal serum and significantly higher than in amniotic fluid. The amniotic fluid contained extremely high tau-glutamyltransferase concentration compared with the other fluids and fetal serum. Alkaline phosphatase and amylase were not detectable in coelomic fluid, fetal serum, or nuchal and hygroma fluid. The nuchal and hygroma fluid composition was similar except for total protein and alpha-fetoprotein concentrations, which were significantly higher in nuchal than in hygroma fluid. The vesicular fluid from the partial mole, fetal serum, and nuchal and hygroma fluid contained extremely high alpha-fetoprotein concentrations, which were significantly higher that those found in amniotic fluid. In complete mole alpha-fetoprotein molecules were of the yolk sac type, whereas they were of the liver type in nuchal and hygroma fluid.

CONCLUSIONS

The composition of vesicular fluid in complete mole reflects a possible origin from the maternal plasma, yolk sac, and trophoblast, whereas the composition of nuchal and cystic hygroma fluid suggests a leakage from the fetal circulation.