Bruno Severi

Epithelioid leiomyoma of the breast with granular cell change : a case report

A 42-year-old woman with an epithelioid granular cell leiomyoma of the right breast is reported. The cells were spindle to polygonal and displayed finely granular cytoplasm. The smooth muscle differentiation of this tumor was shown by the immunohistochemical positivity of the neoplastic cells with anti-alpha smooth actin and antidesmin antisera. Microfilaments with focal densities were present in the cytoplasm at an ultrastructural level. The granular cytoplasmic changes are related to a relevant number of lysosomes within the neoplastic cells.

Ultrastructural and immunohistochemical contribution to the histogenesis of human cardiac myxoma.

The ultrastructural features of 8 human cardiac myxomas were analyzed and correlated with immunohistochemical data, with the aim to clarify the characteristics of the cell lines involved in the tumor genesis. Immunohistochemical studies were performed to detect the presence and the distribution of intracytoplasmic filaments (vimentin, desmin, actin, myosin) as well as myoglobin and factor VIII-related antigen, albumin, and lysozyme. Eighty percent of myxoma cells were simultaneously positive for vimentin, desmin, and actin, whereas 30% of them stained with antifactor VIII and antivimentin antibodies. The submicroscopic analysis revealed two main cell populations: (1) one composed of stellate-shaped cells with scanty organelles and sparse hyaloplasmic filaments scattered throughout the myxoid stroma and forming a loose network with their projections; (2) another one included cells with more cytoplasmic organelles, intermediate filaments, and myofilaments arranged either singly or in both solid and hollow cord-like structures. Our results support the hypothesis that cardiac myxoma may originate from a reserve multipotent mesenchymal cell able to differentiate more or less completely along two major evolutional lines: myoid and endothelial. The tumor tissue thus seems to be involved in vessel formation, suggesting a growth pattern akin to that manifested in other forms of endocardial pathological reactivity in which reserve mesenchymal cells are engaged.

Benign smooth muscle cell metaplasia in breast.

Three different benign breast lesions showing smooth muscle cells in the stroma are reported. Benign smooth muscle cells are rarely found in the breast, and it is likely that they originate from metaplastic changes of the stroma itself.

Ependymoma of the Foramen of Monro: Ultrastructural Characterization

The characteristics of clear cells of an ependymoma of the foramen of Monro have been studied by electron microscopy to precisely define its organellar composition and to establish the tumor histogenesis. Our data confirm that the once-thought oligodendroglial is, in fact, an ependymal tumor. Both the scarce number of organelles, owing to the low degree of differentiation, and the abundance of hyaloplasmic lipid vacuoles can account for the clear appearance of these tumor cells.

Brenner tumor of the ovary: a correlative histologic, histochemical, immunohistochemical, and ultrastructural investigation.

The histologic, histochemical, immunohistochemical, and ultrastructural features of Brenner tumor (BT) were studied. BT was compared with transitional bladder cells, and close similarities between the two tissues were identified. Abundant glycogen in all cellular layers, an alcianophilic/sialomucinic surface mucous coat, and argyrophilic cells characterized both BT and bladder epithelium. Immunohistochemically, chromogranin and neuron-specific enolase reactivity was observed in all cases examined. An additional relevant finding was the presence of serotonin-storing cells in both BT and urothelium. Moreover, carcinoembryonic antigen, epithelial membrane antigen, and keratin reaction were found in BT and urothelium, indicating an additional antigenic similarity. Additionally, malignant Brenner tumor was ultrastructurally found to share many common features with the bladder tissue. The distinct histochemical, ultrastructural, and antigenic pattern of BT, primarily of the transitional type, is emphasized.

Stromal cells in primary myelofibrosis: ultrastructural observations.

SummaryThe bone marrows of five patients with primary myelofibrosis at different stages of the disease have been studied. In the myelofibrotic bone marrow, associated with “reticulum cells”, two other cell types have been identified, namely fibroblast-like and myofibroblast-like reticulum cells, as well as a spectrum of transitional forms.Our findings suggest that reticulum cells may represent a reserve stromal cell pool (i.e. primitive reticulum cells) able to modulate themselves and to transform differently according to functional requirements.Some suggestions regarding the functional significance of fibroblastlike and myofibroblast-like reticulum cells in primary myelofibrosis are suggested.

Elastofibroma: An In Vivo Model of Abnormal Neoelastogenesis

Thirteen cases of elastofibroma have been studied by conventional light and electron microscopy, as well as by histochemistry and immunohistochemistry. By light microscopy elastinophilic material appeared as huge fibers crossing collagen bundles. Immunohistochemistry demonstrated a strong positivity for elastin in numerous and circumscribed areas of the extracellular matrix. By electron microscopy, collagen consisted of 40-50-nm wide fibrils, and elastin was made of large aggregates of moderately electron-dense material surrounding a very thin, apparently normal, elastin core. At high magnification these aggregates consisted of short tubules, often in regular arrays, surrounded by microfibrils and microfilaments. These data, associated with selective digestions on thin sections with elastase, purified collagenase, hyaluronidase, and chondroitinase ABC, revealed that elastic fibers in elastofibroma seem to be made of true elastin surrounded by an enormous amount of hydrophilic material, in which some elastin, chondroitin sulfates, and collagenase type-VII sensitive material are aggregated forming a rather ordered array of short tubules.

Postmastectomy angiosarcoma: ultrastructural study of a case

The ultrastructural findings of a case of Stewart-Treves syndrome are reported. The authors believe that some features, never described before, confirm the truly vascular nature of this neoplasm.

Hyaline globules in ovarian tumours

therefore believe this is a quick, simple, inexpensive and reliable means of provisionally distinguishing gold from other black granular deposits. A confirmatory history of chrysotherapy should be obtainable with ease. We fully accept the valuable role of X-ray microanalysis in such circumstances, but few units have direct access to this facility which also has significant associated costs. All our cases have been biopsied within the past 2-3 years, with the skin cases forming part of a research programme in the Department of Rheumatology locally. Whilst we agree that chrysiasis is not a common condition, we should point out that gold deposits in lymph nodes draining injection sites may occur in the absence of established chrysiasis. Awareness of this feature of gold should be of significant value to all practising pathologists who may encounter such cases.