Multiple expressions of lymphatic markers and morphological evolution of newly formed lymphatics in lymphangioma and lymph node lymphangiogenesis

Clinical Case of Fetal Lymphangioma

Lymphangioma is a benign lymphatic system tumor, often congenital, mainly affecting lymph nodes in various anatomic localizations. Postnatally mostly common lymphangioma manifestation occurs during the first year of life. Today it can be readily diagnosed prenatally. Diagnosis is based on non-invasive visualization, such as sonography and computed tomography. The objective: is to present clinical case of manifest fetal lymphangioma diagnosed during pregnancy. Fetal ultrasound (US) was performed at 28, 32, 34 weeks of gestation. As a result fetus was diagnosed with hypoechogenic mass in right axillary region, growing in dynamics gradually from 34×28 mm, 38×34 mm to 49×37 mm. Mass had clear even contours, hyperechogenic capsule with fine dispersed suspension content. Color doppler imaging showed avascular mass character. After delivery at 37–38 weeks of gestation (planned Cesarean section) at newborn examination we visualized asymmetric soft elastic consistency protrusion along right midclavicular and anterior axillary region. Described clinical case of fetal lymphangioma is a good illustration of dynamic prenatal and postnatal dynamic observation and its US interpretation.

Systemic generalised lymphangiomatosis: unknown aetiology and a challenge to treat

We describe a case of a woman diagnosed at the age of 35 years with a generalised mediastinal and abdominal lymphangiomatosis associated with a protein losing enteropathy, who successfully improved when treatment with sirolimus was initiated.

Lymphatic Reconstitution and Regeneration After Face Transplantation

BACKGROUND

The purpose of this study was to investigate whether lymphatic reconstitution and regeneration occurs after clinical facial transplantation using indocyanine green lymphography and immunohistochemical markers.

METHODS

Allograft skin biopsies at multiple posttransplant time points were stained with Lyve1 lymphatic antibody and other endothelial antibodies. Staining intensity was interpreted on a scale of none, mild, moderate, and strong by 2 investigators and consolidated by a third party for final interpretation. Standardized real-time lymphography was performed at various posttransplant time points to evaluate lymphatic reconstitution and regeneration.

RESULTS

Forty-two biopsies were evaluated at 15 different time points from posttransplant days 7 to 420. Strong Lyve1 staining was observed in 52.4%, moderate staining in 14.3%, and weak staining in 33.3% of biopsies. Strong staining was present on days 7, 10, 44, 79, 269, 402, and 420. Three lymphographic studies were conducted at 8.5, 30, and 35 months posttransplant. Initial drainage via distinct lymphatic channels with abrupt dermal splash and lymphostasis was observed at 8.5-month posttransplant. At 30- and 35-month posttransplant, communication of multiple lymphatic channels between donor tissue and recipient tissue was evident with distinct drainage into native recipient cervical lymph nodes. This correlated with ongoing clinical resolution of facial edema and was unaffected by 3 episodes of acute rejection.

CONCLUSIONS

These findings support ongoing lymphatic reconstitution between the donor facial allograft and recipient native tissue. Donor lymphatic regeneration begins after facial transplantation and continues long term. This mechanism may be responsible for the temporal and spatial process of lymphatic reconstitution with recipient lymphatic channels.

Cross-sectional study comparing different therapeutic modalities for cystic lymphangiomas in children

OBJECTIVE

Here, we describe our experience with different therapeutic modalities used to treat cystic lymphangiomas in children in our hospital, including single therapy with OK-432, bleomycin and surgery, and a combination of the three modalities.

METHODS

We performed a retrospective, cross-sectional study including patients treated from 1998 to 2011. The effects on macrocystic lymphangiomas and adverse reactions were evaluated. Twenty-nine children with cystic lymphangiomas without any previous treatment were included. Under general anesthesia, patients given sclerosing agents underwent puncture of the lesion (guided by ultrasound when necessary) and complete aspiration of the intralesional liquid. The patients were evaluated with ultrasound and clinical examinations for a maximum follow-up time of 4 years.

RESULTS

The proportions of patients considered cured after the first therapeutic approach were 44% in the surgery group, 29% in the bleomycin group and 31% in the OK-432 group. These proportions were not significantly different. Sequential treatment increased the rates of curative results to 71%, 74% and 44%, respectively, after the final treatment, which in our case was approximately 1.5 applications per patient.

CONCLUSION

The results of this study indicate that most patients with cystic lymphangiomas do not show complete resolution after the initial therapy, regardless of whether the therapy is surgical or involves the use of sclerosing agents. To achieve complete resolution of the lesions, either multiple operations or a combination of surgery and sclerotherapy must be used and should be tailored to the characteristics of each patient.

Rapamycin inhibition of CFA-induced lymphangiogenesis in PLN is independent of mast cells

Elucidation of the events responsible for the interaction between lymphatic endothelial cells (LECs) and mast cells (MCs) may prove to be a valuable source for controlling lymphangiogenesis. In the present study, we compared immunohistochemical and RT-PCR findings of the popliteal lymph node (PLN) and footpad skin in C57BL/6J and WBB6F1 mice, the MC-deficient strain. The results indicated that MCs play certain role in complete Freund's adjuvant-induced intranodal lymphangiogenesis. VEGF-A, VEGFR-2 and TNF-α were crucial factors in lymphangiogenesis both in the PLN and skin. Moreover, the in vivo administration of the specific mTOR inhibitor, rapamycin inhibited lymphangiogenesis independent of MCs in PLN rather than in the skin. Further study on anti-lymphangiogenic effect will contribute to our understanding of LEC and MC modulation in pathological lymphangiogenesis.

Macrophages are important mediators of either tumor- or inflammation-induced lymphangiogenesis

The lymphatic system provides important functions for tissue fluid homeostasis and immune response. Lymphangiogenesis, the formation of new lymphatics, comprises a series of complex cellular events in vitro or in vivo, e.g., proliferation, differentiation, and sprouting. Recent evidence has implied that macrophages act as a direct structural contributor to lymphatic endothelial walls or secret VEGF-C/-D and VEGF-A to initiate lymphangiogenesis in inflamed or tumor tissues. Bone marrow-derived macrophages are versatile cells that express different functional programs in response to exposure to microenvironmental signals, and can be identified by specific expression of a number of proteins, F4/80, CD11b, and CD68. Several causative factors, e.g., NF-κB, IL-1β, TNF-α, SDF-1, M-CSF, especially TonEBP/VEGF-C signaling, may be actively involved in macrophage-induced lymphangiogenesis. Alteration of macrophage phenotype and function has a profound effect on the development and progression of inflammation and malignancy, and macrophage depletion for controlling lymphangiogenesis may provide a novel approach for prevention and treatment of lymphatic-associated diseases.