[Micronodular generalized familial angiomatosis (generalized essential telangiectasia): clinical cases; ultrastructural study]. / Angiomatose familiale micronodulaire généralisée. (télangiectasies essentielles généralisées): observations cliniques; étude ultrastructurale.

Six patients of the same family present with micronodular and generalized familial angiomatosis. Four of them have been investigated. Their problem is purely esthetic; however an asymptomatic form of von Willebrand disease has been found in a female and one of her daughters. The light microscope reveals a network of dilated capillaries in the superficial dermis. Electron microscope investigation of the endothelium demonstrates on abundance of Weibel-Palade bodies, the presence of osmiophilic inclusions within clear vacuoles, the occurrence of long spacing collagen fibrils in the vicinity of endothelial and perithelial cells; furthermore, cytoplasmic projections within the lumen constitute the most dramatic and constant feature: there are many villosities, loops, coils, tufts and entanglements in all four cases.

Histopathologic investigation of a case of meningioangiomatosis not associated with von Recklinghausen's disease.

A case of meningioangiomatosis not associated with von Recklinghausen's disease is reported. Microscopically, irregularly branched blood vessels extending into the gray matter from the meningeal surface are surrounded by a concentric arrangement of proliferating spindle-formed cells. Ultrastructurally these proliferating cells are composed of elongated heterochromatin-rich nuclei and slender cytoplasm-containing microfilaments, occasionally associated with desmosomal junctions and basal laminalike structures. Judging from these findings, together with a negative immune reaction for S-100 protein, the histogenesis of these proliferating cells is most probably meningothelial in origin.

Sclerosing haemangiomas of the lung.

A series of 29 pulmonary sclerosing haemangiomas is analysed. Included is one case with multiple tumours and another with metastatic growth in a hilar lymph node. Histochemical and electron microscopic studies show that type 2 pneumocytes are an important constituent cell type though bronchial structures, tumorlets and angiomas also occur within these tumours. They are considered to be pulmonary hamartomas formed from distal lung structures. They are of slow growth and have been confused in the past with pulmonary histiocytomas and plasma cell granulomas.

von Hippel angiomatosis. A light, electron microscopic, and immunoperoxidase characterization.

A 25-year-old Iranian man had undergone eye wall resection of a large von Hippel angioma to alleviate an exaggerated macular response, affording study by light and electron microscopy and immunohistochemistry before the obfuscatory effects of long-standing exudative retinal detachment, gliosis, or iatrogenic ablation supervened. We used this vantage point to assess the interrelation between the component endothelial cells, pericytes, and stromal foam cells. On the basis of staining with glial fibrillary acidic protein, factor VIII, the C3 fraction of complement, fibrinogen, and lysozyme, it is unlikely that stromal foam cells derive from glial precursors, but may represent degenerating cells, perhaps arising from a common vasoformative stem cell under hypoxic stress.

Juxtapapillary retinal hemangioblastoma (angiomatosis retinae) in an infant: light microscopical and ultrastructural examination.

A retinal tumor in an 8-month-old boy clinically resembled a retinoblastoma. Light microscopic and ultrastructural examination revealed a hemangioblastoma (von Hippel's disease). It was mainly composed of large, light, lipid-containing cells (so-called stroma cells) lying between numerous vessels, which ultra-structurally were seen to be surrounded by several layers of pericytes separated by abundant basement membrane material. The origin of the stromal cells is discussed in particular. Ultrastructural examination of this tumor has not previously been performed in such an early case, but 2 adult cases have been recorded. Based on their findings the authors favor a vascular origin but conclude that the derivation of the stroma cell is still unresolved.

Metastatic carotid body paraganglioma in von Hippel-Lindau disease. An electron microscopic study.

Pulmonary metastases from a carotid body paraganglioma developed in a patient with von Hippel-Lindau disease. On electron microscopic examination, these metastases consisted solely of chief cells that contained membrane-bound, dense-core granules and formed numerous cytoplasmic processes. These data support the hypothesis that the chief cell is the sole neoplastic cell in paragangliomas. Finally, to our knowledge, this clinical association of a malignant carotid body paraganglioma and pheochromocytoma in von Hippel-Lindau disease is unique.

Intramuscular angiomatosis of pelvic wall complicating pregnancy. Clinical, histological, and ultrastructural observations.

This is the first report of intramuscular angiomatosis involving the right bulbocavernous muscle in a pregnant woman, who underwent a cesarean section because of the risk of dystocia. The tumor was formed by well- and poorly differentiated vessels infiltrating the skeletal muscle fibers, which showed various degrees of degeneration. On electron microscopy, the neoplastic vessels were formed by large endothelial cells rich in organelles, limiting a luminal space and surrounded by a multilayered basal lamina. Pericytes were usually present around the endothelial layers. The neoplastic vascular structures seemed to grow by a process of gemmation. Our observations confirm the notion that this kind of benign neoplasm may pursue a rapidly growing course and presents a disturbing histological appearance which requires proper interpretation and precise diagnosis.

The ultrastructure of Sturge-Weber disease.

Five infantile and one adult case of Sturge-Weber disease were studied pathologically. The calcification occurring under the leptomeningeal angiomatosis increased with advancing age. Light and electron microscopy of two cases showed the smallest, and therefore possibly the earliest, calcifications occurred in perithelial cells. It is hypothesized the cause of calcification is anoxic injury to endothelial, perithelial and possibly glial mitochondria due to stasis and abnormal vessel permeability in the cerebral vessels composing the Sturge-Weber angioma.

Angiomatosis retinae. An ultrastructural study and lipid analysis.

A nonfamilial case of agiomatosis retinae (retinal hemangioblastoma) was studied by electron microscopy. In addition to the three major types of cells previously identified within the tumor (endothelial cells, pericytes, heavily lipidized stromal cells), fibrous astrocytes in different stages of lipidization were also found. The endothelial cells were fenestrated, providing the basis for the extravasated exudate that is characteristic of the tumor. The pericytes were completely surrounded by casement membranes and displayed no significant lipidization; in a cellular plaque of vasular tissue at the base of the lesion, however, some of the multilaminar pericytes showed evidence of early smooth muscle differentiation. The stromal cells contained abundant lipid vacuoles and a few organelles, and exhibited granular degeneration of cytoplasmic filaments between the lipid vacuoles. There was spotty basement membrane formation where the stromal cells abutted on the vascular elements. No interconversion could be demonstrated among the endothelial cells, pericytes, and stromal cells. A source for the stromal cells was discovered in the early lipisization of fibrous astrocytes. Analysis of the extracted lipid from the tumor by means of infrared spectroscopy, lipid chromatography, and x-ray diffraction disclosed that the lipid was mostly cholestrol stearate, a plasma lipid. It is suggested that in the retinal lesions the leaky (fenestrated) capillaries of the tumor allowed the passive imbibition of plasma lipid by the fibrous astrocytes, leading to their gradual transformation into the fully lipidized stromal cells.