Lymphatic endothelial celline (CH3) from a recurrent retroperitoneal lymphangioma

Summary An endothelial cell line derived from a massive recurrent chyle-containing retroperitoneal lymphangioma was isolated in monolayer culture. Scanning and transmission electron microscopy and immunohistochemistry confirmed a close resemblance to blood vascular endothelium with typical cobblestone morphology, positive immunofluorescence staining for endothelial marker Factor VIII-associated antigen and fibronectin, and prominent Weibel-Palade bodies. The endothelial cells also exhibited other ultrastructural features characteristic of lymphatic endothelium, including sparse microvillous surface projections, overlapping intercellular junctions, and abundant intermediate filaments. This endothelial cell line represents a new source of proliferating lymphatic endothelium for future study, including structural and functional comparison to blood vascular endothelium. Supported in part by Arizona Disease Control Research Commission contracts 8277-000000-1-1-AT-6625 and ZB-7492. Presented in part at the 10th International Congress of Lymphology in Adelaide, Australia, August 1985.     

Lymphatic Endothelial Tumors Induced by Intraperitoneal Injection of Incomplete Freund's Adjuvant

Endothelial cells form the inner lining of blood and lymphatic vessels. In mice, only tumors of the blood vessel endothelium (haemangiomas) have been thus far reported. Here we describe a highly reproducible method for the induction of benign tumors of the lymphatic endothelial cells (lymphangiomas) in mice by intraperitoneal injection of incomplete Freund's adjuvant. Morphological and histopathological studies of the lesions revealed the presence of cells at various levels of vascular development. The lymphangiomas developed in the peritoneal cavity and expressed the endothelial markers CD31/PECAM (platelet endothelial cell adhesion molecule), CD54/ICAM-1 (InterCellular Adhesion Molecule-1), and CD102/ICAM-2, as well as the vascular endothelial growth factor (VEGF) receptor Flk-1, the endothelial cell specific receptors Tie-1 and Tie-2 and the lymphatic endothelial cell specific Flt4 receptor as shown byin situhybridization. The Flk-1 and Flt4 receptors were also identified in immunoblots of the tumors and in cells cultured from them. When induced in β-galactosidase knock-in Flt4^+/−mice, the tumor endothelia could be stained blue in a number of tumor cells although the staining was of lower intensity than in normal lymphatic vessels. The tumor-derived cells could be propagatedin vitroand they spontaneously differentiated, forming vessel-like structures. Murine lymphangiomas thus represent a highly reproducible and convenient source of lymphatic endothelial cells.     

Lymphangioma of the pancreas: a multimodal approach to pre‐operative diagnosis

Background: Lymphangioma of the pancreas is an extremely rare benign tumour of lymphatic origin, with only four cases diagnosed by EUS‐FNA reported to date. Methods and materials: Five cases of either cytologically or histologically diagnosed pancreatic lymphangioma with pre‐operative cytological analysis by EUS‐FNAC were reviewed. Results: All patients were female, with a mean age of 56.4 years. By imaging, the cystic lesions ranged in size from 2 to 7 cm (mean 4.5 cm) and were mainly located in the head of the pancreas. All cysts had thin walls and no cyst demonstrated a mural nodule. Diagnosis based on imaging features was benign in all cases due to the absence of high‐risk features. Four samples were sent for biochemical analysis, which showed low CEA levels (range, <0.5–19.4 ng/ml; mean, 5.45 ng/ml) and CA 19.9 and CA 72.4 levels within normal range. All cyst fluids showed numerous small lymphocytes with no atypia; no epithelial cells were present, including no gastrointestinal contamination. Flow cytometry in two cases showed T lymphocytes with a mature phenotype. Surgical resection in two patients confirmed the cytological diagnosis. Benign clinical follow‐up was available in three patients at 2, 3 and 3.5 years. Conclusion: A multimodal approach to cytological diagnosis (combining clinical, radiological and cyst fluid gross, biochemical and cytological characteristics) can lead to the diagnosis of this cystic neoplasm and distinguish it from other more common cysts in the pancreas, potentially avoiding the need for unnecessary surgery.     

Cytology of benign multicystic peritoneal mesothelioma in peritoneal washings

Objective:  To describe the cytological aspect of peritoneal washings in benign multicystic peritoneal mesothelioma (BMPM).
Methods:  Three peritoneal washing specimens stained by standard cytological and histological procedures and analysed by light microscopy.
Results:  The specimens showed an abundance of monomorphous mesothelial cells devoid of atypia or mitoses. The mesothelial cells were calretinin positive. They also showed numerous squamous metaplastic cells arranged in flat sheets or isolated cells. The background contained some inflammatory cells.
Conclusion:  The combination of cytology of the peritoneal washing, histology (cell block and surgical specimen) and clinical history allow differentiation of BMPM from other cystic lesions (cystic lymphangioma and malignant mesothelioma).