Giant benign lymphangioendothelioma with positive expression of Wilms tumor 1: A case report.

Benign lymphangioendothelioma (BL, acquired progressive lymphangioma) is a rare, slow-growing lymphatic tumor, first described 40 years ago, with fewer than 50 published cases. Clinically, it presents as a skin-colored or erythematous patch. Definitive diagnosis requires histopathological examination. The immunohistochemical staining profile is still controversial regarding Wilms tumor 1 (WT1) expression, a marker of proliferative and neoplastic, rather than malformative nature. Here, we report a case of a 60-cm-long BL on the breast of an adult female. Biopsy revealed irregular vascular spaces dissecting the collagen bundles lined by swollen endothelial cells but without cellular atypia. Positivity for podoplanin (D2-40), CD31, and WT1 was observed, supporting the neoplastic nature of this lesion. Dermatologists and pathologists must be aware of this entity for early diagnosis and treatment.

The Roles of Neuropilin 2/VEGF-C Axis in a Series of Recurrent Lymphangioma.

INTRODUCTION: Vascular endothelial growth factor (VEGF) and its receptor act as a major contributor to lymphangioma, but their role on nonrecurrent and recurrent lymphangiomas remain unclear. We aim to investigate those factors in the generation of recurrent lymphangioma. MATERIALS AND METHODS: Patients diagnosed with lymphangioma from January 2005 to December 2012 in our hospital were collected and divided into nonrecurrent and recurrent lymphangiomas. The clinical characteristics including age, sex, symptoms, location, and size of lymphangioma were collected. Surgical resection samples were collected for histology, protein and mRNA detection of VEGF-C, VEGF receptor-3 (VEGFR-3), and neuropilin 2 (Nrp2). Follow-ups including lymphangioma recurrent and the local symptoms such as ulcer were reviewed. RESULTS: A total of 80 patients aged from 5 months to 12 years were enrolled in this study, 51 patients had no recurrence and other 29 patients suffered from recurrent lymphangioma. There was no significant difference in demographic data and clinical characters between the two groups (p > 0.05). Immunohistochemistry staining showed that VEGFR-3 remained unchanged between nonrecurrent and recurrent lymphangiomas (p > 0.05), and VEGF-C and Nrp2 were significantly increased in recurrent lymphangioma compared with nonrecurrent lymphangioma (p < 0.05). The same expression trend was proved as detected by protein and mRNA levels. CONCLUSION: The VEGF-C/Nrp2 axis was significantly increased in the recurrent lymphangioma, indicating that VEGF-C/Nrp2 targeted therapy may serve as a potential therapeutic strategy for recurrent lymphangioma.

Intussusceptive Lymphangiogenesis in Lymphatic Malformations/Lymphangiomas.

Intussusception in lymphatic vessels has received less attention than in blood vessels. In tumors and pseudotumors of blood vessels with intravascular papillary structures, including sinusoidal hemangioma and intravascular papillary endothelial hyperplasia, we observed exuberant intussusceptive angiogenesis, as well as the similarity between papillae (term used by pathologists) and pillars/folds (hallmarks of intussusceptive angiogenesis). A similar response could be expected in lymphangiomas (lymphatic malformations and reactive processes rather than tumors) with papillae. The aim of this work is to assess whether papillae/pillars/folds and associated structures (vessel loops and septa) are present in lymphangiomas, and to establish the characteristics and formation of these structures. For this purpose, we selected lymphangiomas with intraluminal papillae (n = 18), including cystic, cavernous, circumscriptum, and progressive types, of which two cases of each type with a greater number of papillae were used for serial histologic sections and immunohistochemistry. The studies showed a) dilated lymphatic spaces giving rise to lymphatic-lymphatic vascular loops, which dissected and encircled perilymphatic structures (interstitial tissue structures/ITSs and pillars/posts), b) ITSs and pillars, surrounded by anti-podoplanin-positive endothelial cells, protruding into the lymphatic spaces (papillary aspect), and c) splitting, remodeling, linear arrangement, and fusion of papillae/pillars/folds, forming papillary networks and septa. In conclusion, as occurs in blood vessel diseases, the development of lymphatic vessel loops, papillae/pillars/folds, and septa (segmentation) supports intussusceptive lymphangiogenesis and suggests a piecemeal form of intussusception. This intussusceptive lymphangiogenesis in lymphatic diseases can provide a basis for further studies of lymphatic intussusception in other conditions, with clinical and therapeutic implications. Anat Rec, 302:2003-2013, 2019. © 2019 American Association for Anatomy.

Signaling pathways and inhibitors of cells from patients with kaposiform lymphangiomatosis.

BACKGROUND: Kaposiform lymphangiomatosis (KLA) is a rare lymphatic anomaly with significant morbidity and mortality. KLA is characterized by diffuse multifocal lesions comprised of focal areas of "kaposiform" spindled cells accompanying malformed lymphatic channels. The goal of this study was to identify activated signaling pathways in cells isolated from three KLA patients for the purpose of testing new therapies. PROCEDURE: Cells were obtained from the lungs of one patient isolated at autopsy and the spleen of two patients removed in surgery due to disease complications. A protein kinase array was performed on the KLA cell lysates and normal lymphatic endothelial cells. RESULTS: Higher activation of key signaling pathways in the KLA cells, including PRAS40, AKT1/2/3, and ERK-1/2, was identified by protein kinase array and confirmed by Western blot analysis. This indicated a role for highly activated PI3K-AKT and MAPK-ERK-1/2 signaling pathways in KLA cells. Cell proliferation studies assessed PI3K inhibitors (LY294002; BYL719), AKT inhibitor ARQ092, mTOR inhibitor rapamycin, and MAPK inhibitor U0126. These studies demonstrated that PI3K-AKT-mTOR and MAPK signaling are important mediators of KLA cell proliferation. BYL719 and rapamycin were more effective at inhibiting KLA cell proliferation than U0126. CONCLUSIONS: Our studies using cells from KLA patient lesions demonstrate that these cells are highly proliferative and the PI3K-AKT-mTOR and MAPK pathways are promising therapeutic targets. Development and clinical trials of PI3K, AKT, and MAPK inhibitors for cancer treatment and the data in this study lend support for early clinical trials assessing the efficacy of these inhibitors in KLA patients.

Benign lymphangioendothelioma presenting as a giant flank mass.

Benign lymphangioendothelioma is a rare lesion of controversial etiology and a histopathologic mimic of Kaposi sarcoma and so-called 'well-differentiated' angiosarcoma. Its most typical clinical presentation is as a slowly expanding, erythematous patch or plaque; it rarely presents as a large mass. We report the second case of a giant benign lymphangioendothelioma, which arose as a serpiginous mass involving most of the flank of an elderly male with no prior radiation exposure and with a remote history of herpes zoster infection. A biopsy revealed numerous anastomosing vascular channels extending from the superficial dermis to the subcutis that were dilated to progressively slit-like in architecture. The endothelial cells lacked cytologic atypia, hobnailing, or significant mitotic activity, and human herpesvirus-8 expression was absent. Positivity for podoplanin (D2-40) was observed in the endothelial cells, supporting a lymphatic phenotype. Furthermore, the lesional cells lacked immunohistochemical expression of Wilms tumor 1, providing further support of a malformative - rather than neoplastic - pathogenesis.

Novel characterization of bEnd.3 cells that express lymphatic vessel endothelial hyaluronan receptor-1.

Murine bEnd.3 endothelioma cell line has been widely used in vascular research and here we report the novel finding that bEnd.3 cells express lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and vascular endothelial growth factor receptor-3 (VEGFR-3). Moreover, these cells express progenitor cell markers of Sca-1 and CD133. Upon stimulation with tumor necrosis factor-alpha (TNF-alpha), the bEnd.3 cells demonstrate enhanced formation of capillary-type tubes, which express LYVE-1. As the bEnd.3 cell line is derived from murine endothelioma, we further examined human tissues of endothelioma and identified lymphatic vessels in the tumor samples which express both LYVE-1 and podoplanin. Moreover, a significantly higher number of lymphatic vessels were detected in the endothelioma samples compared with normal control. Taken together, this study not only redefines bEnd.3 cells for vascular research, but also indicates a broader category of human diseases that are associated with lymphatics, such as endothelioma.

Benign lymphangioendothelioma: a clinical, histopathologic and immunohistochemical analysis of four cases.

BACKGROUND: Benign lymphangioendothelioma represents a rare lymphatic vascular proliferation characterized by proliferation of irregular and thin-walled vessels dissecting amongst dermal collagen. Immunohistochemical analysis has been lacking in most previously reported cases. METHODS: Herein, we report the clinical and histopathologic characteristics of four cases of benign lymphangioendothelioma. Immunohistochemical study was completed for all lesions. RESULTS: All lesions presented as large, red to brown patches or plaques. Three lesions were located on the thigh and one lesion was located on the neck. Histopathologically, all lesions showed proliferation of anastomotic or retiform thin-walled vessels with a single layer of endothelial cells that dissect the dermis. D2-40 and Prox1 immunostains were positive and Wilms tumor 1 (WT-1) immunostain was negative in all cases. CONCLUSION: Benign lymphangioendothelioma represents a lymphatic vascular proliferation. A lack of expression of WT-1 suggests it represents a lymphatic vascular malformation.

Maldevelopment of dermal lymphatics in Wnt5a-knockout-mice.

Maintenance of tissue homeostasis and immune surveillance are important functions of the lymphatic vascular system. Lymphatic vessels are lined by lymphatic endothelial cells (LECs). By gene micro-array expression studies we recently compared human lymphangioma-derived LECs with umbilical vein endothelial cells (HUVECs). Here, we followed up on these studies. Besides well-known LEC markers, we observed regulation of molecules involved in immune regulation, acetylcholine degradation and platelet regulation. Moreover we identified differentially expressed WNT pathway components, which play important roles in the morphogenesis of various organs, including the blood vascular system. WNT signaling has not yet been addressed in lymphangiogenesis. We found high expression of FZD3, FZD5 and DKK2 mRNA in HUVECs, and WNT5A in LECs. The latter was verified in normal skin-derived LECs. With immunohistological methods we detected WNT5A in LECs, as well as ROR1, ROR2 and RYK in both LECs and HUVECs. In the human, mutations of WNT5A or its receptor ROR2 cause the Robinow syndrome. These patients show multiple developmental defects including the cardio-vascular system. We studied Wnt5a-knockout (ko) mouse embryos at day 18.5. We show that the number of dermal lymphatic capillaries is significantly lower in Wnt5a-null-mice. However, the mean size of individual lymphatics and the LEC number per vessel are greater. In sum, the total area covered by lymphatics and the total number of LECs are not significantly altered. The reduced number of lymphatic capillaries indicates a sprouting defect rather than a proliferation defect in the dermis of Wnt5a-ko-mice, and identifies Wnt5a as a regulator of lymphangiogenesis.

Morphoproteomic study of primary pleural angiosarcoma of lymphangioendothelial lineage: a case report.

An unusual case of bilateral primary pleural angiosarcoma with an immunophenotype of lymphangioendothelial lineage is described. Pleural angiosarcoma is a highly malignant neoplasm for which there is currently no standard of care. A comprehensive immunophenotypic characterization established a lymphangioendothelial lineage. A morphoproteomic analysis was also performed to identify the proteins and corresponding molecular pathways activated in the patient's tumor. The information derived from the morphoproteomic studies provides insight into the biology of the tumor and may be useful in formulating therapeutic alternatives.

Acquired vulvar lymphangioma circumscriptum: a comparison of 12 cases with Crohn's associated lesions or radiation therapy induced tumors.

BACKGROUND: Lymphangioma circumscriptum (LC) is a benign lesion of lymphatic origin. Vulvar involvement occurs in various clinical settings. METHODS: We present 12 cases, and compare lesions in patients with Crohn's disease and those associated with pelvic radiation. RESULTS: The average age at presentation was 49 years. Thirty-three percent of the patients had Crohn's disease, 58% had radiation therapy and 9% had no significant medical history. Sixty-seven percent of the patients had multifocal lesions in anatomically distinct regions. Patients presented on average 16 years after onset of predisposing factors. Presenting complaints were pruritus, wetness and vulvar edema. Lesions were clinically heterogeneous, often found on the labia majora. Lesions consisted of dilated lymphatic channels at the junction of the reticular and papillary dermis. The cells lining these spaces lacked cytologic atypicality or mitotic activity. All lesions so examined were immunoreactive for D240. Patients were most often treated with surgical excision followed by laser ablation. Four of twelve patients, all with radiation-associated lesions, experienced disease progression necessitating additional surgery. CONCLUSIONS: Patients with LC secondary to radiation, when compared to those with Crohn's disease, were 10 years younger, more likely to have associated co-morbidities, and frequently experienced disease progression needing additional surgeries. Acquired vulvar LC has multiple causes with differing prognosis.

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

The rapid evolution of reliable technology combined with increasing number of specific markers for lymphatic endothelial cells (LECs) facilitates the investigation of lymphangiogenesis in developing and diseased tissues. Here, we injected incomplete Freund's adjuvant (IFA) peritoneally into BALB/c and nonobese diabetic (NOD) mice to induce lymphangioma and found atypical lymphatic accumulations with intervening fibrous tissue and lymphoid aggregates. Lymphatic markers, LYVE-1 and podoplanin, were used to specifically define the morphological features of the neoplastic lymphatics. The NOD mice (affected by an autoimmune disorder) had fewer and smaller lymphangiomas than the BALB/c mice. Injection of IFA in the footpad skin of the mice also disturbed draining regional lymph node lymphangiogenesis and caused enlargement of popliteal lymph nodes. Molecular analyses of the LECs indicated potential interventions for lymphangioma through vascular endothelial growth factor (VEGF)-A/-C/-D and their receptors, VEGF receptors-2/-3, and Prox-1 signaling pathways. These findings represent an important link between multiple factors and lymphatic disorders.

Does plasminogen activator inhibitor-1 drive lymphangiogenesis?

The purpose of this study is to explore the function of plasminogen activator inhibitor-1 (PAI-1) during pathological lymphangiogenesis. PAI-1, the main physiological inhibitor of plasminogen activators is involved in pathological angiogenesis at least by controlling extracellular proteolysis and by regulating endothelial cell survival and migration. Protease system's role in lymphangiogenesis is unknown yet. Thus, based on its important pro-angiogenic effect, we hypothesized that PAI-1 may regulate lymphangiogenesis associated at least with metastatic dissemination of cancer cells. To address this issue, we studied the impact of PAI-1 deficiency in various murine models of tumoral lymphangiogenesis. Wild-type PAI-1 proficient mice were used as controls. We provide for the first time evidence that PAI-1 is dispensable for tumoral lymphangiogenesis associated with breast cancers either induced by mammary carcinoma cell injection or spontaneously appearing in transgenic mice expressing the polyomavirus middle T antigen (PymT) under the control of a mouse mammary tumor virus long-terminal repeat promoter (MMTV-LTR). We also investigated inflammation-related lymphatic vessel recruitment by using two inflammatory models. PAI-1 deficiency did neither affect the development of lymphangioma nor burn-induced corneal lymphangiogenesis. These novel data suggest that vascular remodelling associated with lymphangiogenesis and angiogenesis involve different molecular determinants. PAI-1 does not appear as a potential therapeutic target to counteract pathological lymphangiogenesis.

Isolation and characterization of lymphatic endothelial cells from human glossal lymphangioma.

Abnormal lymphangiogenesis is associated with several diseases such as tumor metastasis and lymphangioma. Human lymphangioma originated from the transformation of lymphatic endothelium is a benign malformation of lymphatic vessels and its pathogenesis has up to date not been illuminated and its cell model has also not been established. An optimized method was used to isolate lymphatic endothelial cells from human glossal lymphangioma (GL-LECs) and GL-LECs were further primarily cultured and expanded. GL-LECs were of typical cobblestone appearance when they reached confluence. The weible-palade body was observed in the GL-LECs cytoplasm. Almost all GL-LECs were strongly positive for specific lymphatic markers FLT-4, LYVE-1 and prox-1 by immunocytochemistry. Furthermore, three-dimension tube-like capillaries of GL-LECs resembled the lymphatic system in vivo, and the GL-LECs spheroids sprouted radically out to form three-dimensional buds when embedded in the cultured BME. These results indicated that high purity GL-LECs were successfully isolated and expanded. They had the abilities of tube formation and differentiation in vitro, which provide a favorable cell model for further uncovering the pathogenesis of human lymphangiomas.

VEGF-D deficiency in mice does not affect embryonic or postnatal lymphangiogenesis but reduces lymphatic metastasis.

Vascular endothelial growth factor-D (VEGF-D) is one of the two ligands of the VEGFR-3 receptor on lymphatic endothelial cells. Gene-silencing studies in mice and Xenopus tadpoles recently showed that the role of endogenous VEGF-D in lymphatic development is moderate. By contrast, exogenous VEGF-D is capable of stimulating lymphangiogenesis. Nonetheless, its endogenous role in pathological conditions remains largely unknown. Hence, we reassessed its role in disease, using Vegf-d(null) mice. Vegf-d(null) mice were generated that, under physiological conditions, displayed normal embryonic and postnatal lymphangiogenesis and lymphatic remodelling, efficient lymphatic functioning and normal health. Vegf-d(null) mice also reponded normally in models of skin wound healing and healing of infarcted myocardium, despite enhanced expression of VEGF-D in these models in wild-type mice. In contrast, Vegf-d(null) mice displayed reduced peritumoral lymphangiogenesis and lymph node metastasis in an orthotopic pancreatic tumour model. Together, our data indicate that endogenous VEGF-D in mice is dispensible for lymphangiogenesis during development, in postnatal and adult physiology and in several pathological conditions, but significantly contributes to lymphatic metastasis.

Lymphangiomatoid pattern in diffuse malignant mesothelioma of the pleura: a report of six cases.

The multiplicity of epithelioid and mesenchymal forms of diffuse malignant mesothelioma includes patterns that may mimic another process. Identification of the multiplicity of patterns may help in the diagnosis of diffuse malignant mesothelioma. One pattern that has not been described is lymphangiomatoid. We observed six cases with ovoid or elongated or irregular anastomosing vascular-like spaces lined by flattened cells simulating lymphangioma. The luminal spaces could contain proteinaceous material simulating lymph but not erythrocytes. The cells lining the spaces were mesothelial by immunohistochemical staining. The lymphangiomatoid areas never constituted more than 40% of the area of the tumor on the slides. When seen in more solid areas of tumor, the lymphangiomatoid structures generally did not produce diagnostic difficulty. However, when seen at the edge of solid tumor or forming an irregular nodule or invading into adjacent adipose tissue, these lymphangiomatoid structures could be confusing. All six patients had been exposed to asbestos either by occupation or by spousal exposure. Three patients received chemotherapy. One patient died of diffuse malignant mesothelioma of the pleura.

VEGF-C and VEGFR-3 in a series of lymphangiomas: is superficial lymphangioma a true lymphangioma?

Lymphangiomas are commonly regarded as vascular malformations during embryonic development rather than as true neoplasms. VEGF-C and VEGFR-3 are known to be active in the formation of lymphangiomas. However, the significance of the disorders seems to be obscured by confusing different entities. In 114 lymphangiomas, we investigated the clinicopathological features and the expression of VEGF-C and VEGFR-3. The age of patients with lymphangioma circumscriptum or intraabdominal lymphangioma was significantly higher than in patients with cavernous lymphangioma and in patients with cystic hygroma. In cavernous lymphangioma, the age of female patients was significantly higher than in male patients. Five adult cystic hygromas were identified. VEGF-C was detected in 21 of 58 (36%) cavernous lymphangiomas, ten of 28 (36%) cystic hygromas, 0 of 12 (0%) lymphangioma circumscriptum, and four of ten (40%) intraabdominal lymphangiomas. VEGFR-3 was detected in 43 of 58 (72%) cavernous lymphangiomas, 20 of 28 (71%) cystic hygromas, six of 12 (50%) lymphangiomas circumscriptum, and seven of ten (70%) intraabdominal lymphangiomas. VEGF-C was absent from superficial lymphangiomas associated with cavernous lymphangiomas. In typical cases of cavernous lymphangioma, VEGF-C was strongly expressed, suggesting that these cases possessed proliferative activity. In cystic hygroma and intraabdominal lymphangioma, VEGF-C was limited in its distribution. Superficial lymphangiomas more likely represent from peripheral lymphatic dilatation rather than due to growth factor.