Emmerich von Haam

Ultrastructure of a hemangiopericytoma and a glomus tumor

A comparative ultrastructural study of a case of hemangiopericytoma and one of glomus tumor is presented. The study revealed the hemangiopericytoma cells to be large with large irregular nuclei. The intercellular spaces are filled with light osmiophilic material resembling basement membrane. In the glomus tumor, two types of cells are identified. The more frequent cells are epithelioid smooth muscle cells with large ovoid nuclei and cytoplasm filled with fine filaments. The second type of cell is less frequent and is recognized as a mast cell. It is suggested that the release of mast cell granules plays an important role in the contraction of epithelioid smooth muscle and therefore controls the flow of blood in the glomus structure.

Ultrastructure of myoepithelial cells in human mammary gland tumors.

The relationship of myoepithelial cells to epithelial cells in normal mammary gland and in various diseases of this organ were studied. The evidence suggests that myoepithelial cells play an important role in the formation of some benign and malignant tumors of the breast. The study also showed the presence of light and dark myoepithelial cells.

The ultrastructure of fibrocystic disease of the breast.

Twenty‐two cases of fibrocystic disease were studied with light and electron microscopes. Histologically, the manifestations of fibrocystic disease are divided into five groups presenting a consistent light‐ and electron‐microscopic appearance that includes: blunt duct adenosis, epithelial cell hyperplasia, sclerosing adenosis, “myoepithelial cell proliferation,” cyst with atrophic epithelium and cyst with apocrine changes. Fibrous stroma, lymphocytic infiltration and other features found with fibrocystic disease are not described here because of their presence in conditions other than fibrocystic disease. On the basis of the present study it is concluded that fibrocystic disease involves both epithelial and myoepithelial cells of the mammary duct.

Latent effect of DMBA on adrenal glands of Sprague-Dawley rats: An ultrastructural study☆

Abstract The latent effect of DMBA on the adrenal glands of Sprague-Dawley rats was studied by light and electron microscopy. DMBA or its metabolites seem to have a direct effect on the cells of the zona fasciculata and zona reticularis of the adrenal glands, causing severe mitochondrial structural alterations including variation in size. Calcification was observed in the majority of the cases and was believed to be a consequence of adrenal hemorrhage and cellular injury and not the result of a direct effect of DMBA on the adrenal cortical cells.