Cutaneous lymphangioma circumscriptum: frog spawn on the skin.

Lymphangiomas are congenital malformations of the lymphatic system that may involve the skin, subcutaneous tissues, and intestines. They account for 4% of all vascular tumors, but comprise 25% of benign vascular growths in children. They are hamartomatous in nature and may be grouped into cutaneous lymphangioma circumscriptum (CLC), cavernous lymphangiomas, and cystic hygromas. CLC appears localized to the dermis, although frequently extends deeper and laterally. It is important to distinguish CLC, a potentially recurrent disease, from an unusual type of metastatic carcinoma of the skin called carcinoma telangiectoides.

Immunoelectron microscopic characterization of human dermal lymphatic microvascular endothelial cells. Differential expression of CD31, CD34, and type IV collagen with lymphatic endothelial cells vs blood capillary endothelial cells in normal human skin, lymphangioma, and hemangioma in situ.

We performed a comparative investigation of the immunomorphological characteristics of lymphatic and blood microvascular endothelial cells in normal human skin, cutaneous lymphangiomas, and hemangiomas, employing a pre-embedding immunogold electron microscopic technique. We stained for cell membrane proteins that are commonly used for light microscopic characterization of blood endothelial cells. With blood microvascular endothelial cells, we observed uniform labeling of the luminal cell membranes with monoclonal antibodies (MAbs) JC70 (CD31), EN-4 (CD31), BMA120, PAL-E, and QBEND-10 (CD34), and strong staining of the vascular basal lamina for Type IV collagen under normal and pathological conditions. In contrast, lymphatic microvascular endothelial cells in normal human skin and in lymphangiomas displayed, in addition to a luminal labeling, pronounced expression of CD31 and CD34 along the abluminal cell membranes. Moreover, CD31 was preferentially detected within intercellular junctions. The expression of CD34 was mostly confined to abluminal endothelial microprocesses and was upregulated in lymphangiomas and hemangiomas. Type IV collagen partially formed the luminal lining of initial lymphatics and occasionally formed bridges over interendothelial gaps. Our findings suggest a function of transmigration protein CD31 in recruitment of dendritic cells into the lymphatic vasculature. CD34 labeling may indicate early endothelial cell sprouting. The distribution of Type IV collagen also supports its role as a signal for migration and tube formation for lymphatic endothelial cells.

Skeletal-extraskeletal angiomatosis. A clinicopathological study of fourteen patients and nosologic considerations.

We reviewed the consultation files of the ARmed Forces Institute of Pathology for 1951 through 1989 and identified fourteen patients who had had skeletal-extraskeletal angiomatosis. Skeletal-extraskeletal angiomatosis was defined as a benign vascular proliferation involving the medullary cavity of bone and at least one other type of tissue. The age of the patients at the time of initial biopsy ranged from nine months to sixty-nine years (average, twenty-two years; median, ten years). Ten of the patients were male and four were female. The presenting signs and symptoms were highly variable; they included pain (four patients), a mass noted at birth (three patients), a painless mass that developed after birth (two patients), both pain and a mass (one patient), a localized deformity of the thoracic spine (one patient), and anemia associated with chronic bleeding of the gastrointestinal tract (one patient); in this last patient, skeletal lesions subsequently were found and biopsied. Skeletal-extraskeletal angiomatosis was an incidental finding in the remaining two patients. Multiple bones were involved in thirteen of the fourteen patients. Histologically, three patterns of lesion could be identified: cavernous lymphangioma (six patients), cavernous hemangioma (six patients), and arteriovenous hemangioma (two patients). Five of the patients died (three of sepsis associated with persistent lesions of angiomatosis and two of unrelated causes); eight of the patients survived but had residual disease, and one survived and had no evidence of residual disease.

Lymphangioma of the kidney: a pathologic entity distinct from solitary multilocular cyst.

A case of primary renal lymphangioma is reported. This represents the first documented example of such a lesion confirmed by immunocytochemical and ultrastructural studies. Whereas previously regarded as synonymous terms, the recognition of lymphangioma as a pathologic entity distinct from solitary multilocular cyst of the kidney appears warranted. Although rare, lymphangioma should be considered in the differential diagnosis of multicystic lesions of the kidney.

A light microscopical, immunohistochemical, and ultrastructural comparison of hemangiomata and lymphangiomata.

In this study we have compared the light microscopical, immunohistochemical, and ultrastructural features of five hemangiomata of the dermis with five lymphangiomata of the dermis and subcutaneous tissue. We have attempted to define differentiating features with regard to the ultrastructural appearances and the immunohistochemical staining for the endothelial markers factor VIII-related antigen (FVIII:RAg) and Ulex europaeus agglutinin I (UEA-I). In addition, immunolocalization of FVIII:RAg at the ultrastructural level was performed to compare its distribution within endothelial cells of neoplastic blood vessels and lymphatic vessels. The results show that immunohistochemical staining for FVIII:RAg and UEA-I does not differentiate between blood and lymphatic vessels. However, the presence of a fragmented basal lamina and anchoring filaments does distinguish lymphatic vessels from blood vessels ultrastructurally.

Case of lethal multiple pterygium syndrome with special reference to the origin of pterygia.

A case of lethal multiple pterygium syndrome is presented. Besides the anomalies usually associated with this syndrome, cardiac hypertrophy and connective tissue abnormalities were observed. On the basis of these observations, we suggest that an abnormally fragile collagen constitution is the principal disorder in the lethal multiple pterygium syndrome, which is responsible for the pathogenesis of fetal immobility, pterygia, and many of the associated anomalies.

Acquired progressive lymphangioma as a flat erythematous patch on the abdominal wall of a child.

An erythematous patch was noted on the abdominal wall of an 8-year-old boy. The lesion showed a prolonged initial clinical course, followed by rapid later growth, finally reaching 3.7 X 7.0 cm in size over four years. Despite the harmless clinical appearance, the lesion was histologically characterized by tortuous vascular channels with some cellular atypia. Immunoperoxidase staining disclosed no factor VIII-related antigen or reaction to Ulex europaeus I lectin on tumor cells. There has been no recurrence three years after local excision. Although many features in our case resemble those reported in the literature under the term low-grade angiosarcoma, our preferred designation for such cases is acquired progressive lymphangioma, rather than angiosarcoma, because of their benign behavior.

Lymphatic endothelial cell line (CH3) from a recurrent retroperitoneal lymphangioma.

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.

Lymphangioma of the duodenum: an ultrastructural study.

Two cases of duodenal lymphangioma were diagnosed by endoscopy, and light and electron microscopic findings are reported. Ultrastructural studies showed smooth muscle cells around lymphatic vessels, and amyelinic nerve fibers and smooth muscle cells in the interstitium. On the basis of the ultrastructural features, a hamartomatous rather than tumoral origin is suggested for the duodenal lymphangioma. Lymphangiectatic cysts of Letulle and lymphangiectasia are discussed in the differential diagnosis. Submucosal lymphangiomas of the small bowel might be considered lymphangiectatic cysts.

Peritoneal cystic mesothelioma: an electron microscopic and immunohistochemical study of two male patients.

The clinical, pathological, and ultrastructural features of two cases of peritoneal cystic mesothelioma occurring in men were studied. The results of immunohistochemical staining for CAM 5.2, epithelial membrane antigen, carcinoembryonic antigen, and Factor VIII related antigen are reported for the first time and compared with the staining results of two peritoneal cystic lymphangiomas. Although resembling cystic lymphangioma by light microscopy, cystic mesothelioma may have a greater tendency for local recurrence. Staining for CAM 5.2 or epithelial membrane antigen may facilitate the differentiation of these two entities.

Lymphangioma presenting as a nasal polyp in an infant.

We describe a pedunculated lymphangioma presenting as an isolated nasal polyp in an 11-month-old male infant with light and electron microscopic findings. This lesion occurring in an infant must be distinguished from more common benign and malignant intranasal masses.

Malignant endothelial neoplasm arising in the area of lymphangioma: immunohistochemical and ultrastructural observation.

This report presents a rare malignant endothelial neoplasm which arose at the site of a pre-existing lymphangioma. The lymphangioma was located on the right buccal mucosa, and the malignant neoplasm arose 17 years after irradiation of the initial tumor. Clinical, light microscopic and immunohistochemical (Factor VIII-related antigen and Ulex europaeus Agglutinin-I) studies were made, together with observations by transmission and scanning electron microscopy. These studies provide evidence that this malignant neoplasm was well-differentiated and had not yet lost the characteristics of normal lymphatic cells.

Comparative light and electron microscopic studies of cystic and papillary tumors of the peritoneum.

Using a cystic lymphangioma of the greater omentum and a benign cystic mesothelioma as examples, the distinguishing characteristics of cystic peritoneal tumors are shown, using light microscopic and ultrastructural findings. A benign papillary mesothelioma is used for comparison. The cellular structures and growth rate of the mesotheliomas are contrasted with the tissue reactions which are typical for irritated serosa. The diffusely growing papillary mesothelioma is a very rare tumor, the cells of which are similar to normal serosa cells, but also show characteristics of other benign or malignant mesothelial tumors and of reactive proliferated mesothelial cells. The diffusely growing benign cystic mesothelioma has only been described in isolated cases and is characterized by cysts grouped in acini with mainly flat, localized cuboidal cell lining. The histochemical properties and cytological findings correspond closely to those of the papillary tumor or normal peritoneal lining cells. In contrast, the cystic lymphangioma probably represents a congenital defect with a slow growth rate. The structure is characterized by a sponge-like arrangement of smooth-walled cysts, in the walls of which smooth muscle cells and lymph follicles are embedded. The endothelium is also flat and ultrastructurally resembles that of lymph vessels.

Splenic lymphangioma: luminal surface ultrastructure; a scanning electron microscopic study.

A splenic lymphangioma removed from the abdominal cavity during an exploratory laparotomy in a 16 year old girl was studied by light microscopy and scanning electron microscopy (SEM). The tumor was composed of numerous vascular channels some of which were filled with clotted lymph. SEM revealed these channels to be lined with an uniform endothelial lining composed of two morphologic cell types: one with a smooth surface; the other with numerous microvilli. The literature on the SEM of lymphatic vessels and lymphangiomas is reviewed and compared to the splenic lymphangioma.

Congenital polycystic tumor of the atrioventricular node: possible familial occurrence and critical review of reported cases with special emphasis on histogenesis.

Congenital polycystic tumor of the atrioventricular node is a rare tumor of disputed histogenesis. It constant location in the atrioventricular node separates it from other cardiac cysts and tumors of indisputable endodermal origin. New studies of the embryogenesis of conduction tissues provide a reasonable explanation for the site of the lesion. Morphologic and histochemical features of the tumor fail to conclusively favor either a mesothelial or an endodermal genesis. A recently studied case provides some new morphologic observations (complex desmosomes, granule-containing epithelial cells) and suggests the possibility of of familial occurrence.

Angiolymphoid hyperplasia with eosinophilia of the skin. Light microscopic and ultrastructural study of 4 cases.

A clinical, light and electron microscopic study of four patients with angiolymphoid hyperplasia with eosinophilia of the skin is presented. Light-microscopically, the lesions were characterized by the small size and superficial location, the proliferation of mostly delicate vessels with prominent endothelial hyperplasia and cellular areas without distinct vessel structures, but with infiltrates of eosinophilic leukocytes, lymphocytes and plasma cells. Ultrastructurally, a marked proliferation of both endothelial cells and pericytes could be demonstrated and the solid cellular areas were shown to be composed of solid vascular buds. A multi-layered basal lamina was enclosing pericytes and external surfaces of endothelial cells. The differential diagnosis is discussed and it is emphasized that this lesion may be misinterpreted as angiosarcoma.