Acquired cutaneous lymphangiectasia with mesothelial cells reflux in a patient with cirrhotic ascites.

Acquired cutaneous lymphangiectasia with mesothelial cells reflux in a patient with cirrhotic ascites.

Am J Dermatopathol. 2008 Apr

Tomasini C, Butera AC, Pippione M.
Section of Dermatology, II Clinic, Department of Medical Sciences and Human Oncology, University of Turin, Turin, Italy. ctomasini@molinette.piemonte.it

A previously undescribed case of acquired cutaneous lymphangiectasias on the abdomen in a patient with cirrhotic ascites where peritoneal mesothelial cells refluxed in the skin is discussed. A 56-year-old man previously submitted to liver transplantation presented with vesiculobullous lesions on the developed as his cirrhotic ascites progressed. Histology showed dilated lymphatic channels in the upper dermis lined by a single, discontinuous layer of flattened, monomorphous endothelial cells with endoluminal papillary projections. In the deep reticular dermis, we observed irregular thin- often jagged-walled vascular channels lined by a single layer of bland endothelial cells, dissecting the collagen bundles. Vessels in the lumen were medium to large bizarre-shaped polygonal cells with abundant eosinophilic cytoplasm and hyperchromatic and irregular nuclei, arranged in small clusters or as solitary units, focally in close contact with the endothelial lining or free floating within vessel cavities. Immunohistochemistry indicated atypical intraluminal cells to be positive for calretinin, a specific marker for mesothelial cells. Pathophysiologic mechanisms and problems of differential diagnosis of this unique clinicopathologic entity are discussed.

Lippincott, Williams & Wilkins

Embryonic development and malformation of lymphatic vessels.

Embryonic development and malformation of lymphatic vessels.

Novartis Found Symp. 2007

Wilting J, Buttler K, Rössler J, Norgall S, Schweigerer L, Weich HA, Papoutsi M.
Department of Pediatrics 1, Georg-August-University, Goettingen, Germany.

In the human, malformations of lymphatic vessels can be observed as lymphangiectasia, lymphangioma and lymphangiomatosis, with a prevalence of 1.2-2.8 per thousand. Their aetiology is unknown and a causal therapy does not exist. We investigated the origin of lymphatic endothelial cells (LECs) in avian and murine embryos, and compared the molecular profile of LECs from normal and malformed lymphatics of children. In avian embryos, Prox1+ lymphangioblasts are located in the confluence of the cranial and caudal cardinal veins, where the jugular lymph sac (JLS) forms. Cell lineage studies show that the JLS is of venous origin. In contrast, the lymphatics of the dermis are derived from mesenchymal lymphangioblasts located in the dermatomes, suggesting a dual origin of LECs in avian embryos. The same may hold true for murine embryos, where Lyve1+ LEC precursors are found in the cardinal veins, and in the mesenchyme. The mesenchymal cells express the pan-leukocyte marker CD45, indicating a cell type with lymphendothelial and leukocyte characteristics. In the human, such cells might give rise to Kaposi's sarcoma. Microarray analyses of LECs from lymphangiomas of children show a large number of regulated genes, such as VEGFR3. Our studies show that lymphvasculogenesis and lymphangiogenesis occur simultaneously in the embryo, and suggest a function for VEGFR3 in lymphangiomas.

PMID: 18300425 [PubMed - in process]