[Malignant paraganglioma of the retroperitoneal space developing with increased arterial pressure]. / Zlokachestvennaia paraganglioma zabriushinnogo prostranstva, protekavshaiaia s povysheniem arterial'nogo davleniia.

Brief literature data on clinico-morphologic manifestation of retroperitoneal paraganglioma and its differential diagnosis with ectopic pheochromocytoma is presented. A female 31-year old patient is described with a rapid growth of retroperitoneal neoplasm and a concomitant increase of arterial blood pressure, first paroxysmal and then permanent. After the tumor excision (10 X 13 X 16 cm in size), not connected with the adrenal, the blood pressure recovered. The morphologic study provided the evidence for malignant paraganglioma different from ectopic pheochromocytoma in structural polymorphism and small size of neurosecretory granules. The arterial blood pressure increase is suggested to be due to tumor compression on the left kidney vessels.

[Malignant hormonally inactive adrenocortical tumor]. / Zlokachestvennaia gormonal'no-neaktivnaia adrenokortikal'naia opukhol'.

Criteria are discussed, that according to the literature data allow one to consider adrenocortical tumors without cell polymorphism and mitoses as malignant ones. Such criteria include a rapid tumor growth and its large dimensions, necrotic foci, invasion of blastomatous elements into the capsule and their presence in the vascular lumen. A 47-year old female patient is reported with a rapidly growing large neoplasm of the right adrenal. This adrenocortical tumor in spite of the fact that it lacks polymorphism and mitoses of cells is considered as a malignant one (prevalence of cells with an insignificant amount of lipids, extensive necrotic foci, capsular invasion and evidence of tumor cells in the vascular lumen).

[Morphology and histogenesis of so-called fibrous mesothelioma (submesothelial fibroma)]. / O morfologii i gistogeneze tak nazyvaemoi fibroznoi mezoteliomy (submezotelial'noi fibromy).

Clinico-morphological characteristics of a tumor (6 observations) designated in the literature as fibrous mesothelioma are presented. This benign slowly growing tumor appears as an incapsulated dense nodule connected with the visceral layer of the pleura by a thin fibrous "pedicle". Microscopical structure of the tumor consists of outgrowths of monomorphic spindle-shaped cells, hyalinosis foci and abundance of blood vessels in some of its areas. Tumor cells ultrastructurally correspond to fibroblast indicating the connective tissue genesis of the so-called fibrous mesothelioma. This tumor should be distinguished from the group of mesotheliomas and be better called submesothelial fibroma.

[Cancer of the sweat glands (its clinico-morphological characteristics)]. / Rak potovykh zhelez (kliniko-morfologicheskaia kharakteristika).

Based on a review of the literature and the authors' own experience comprising 20 cases, clinical and histological characteristics of sweat gland cancers (SGC) are detailed. Two clinical variants of SGC are distinguished: exophytic (or exophytic-endophytic) with ulceration and endophytic (intradermal). The lapse of time between detection of a SGC and its removal generally ranges from 12 months to 2 or more years. It is shown that diagnostic and prognostic considerations warrant classifying these cancers into two groups: those arising from benign tumors and retaining their histologic and ultrastructural features (one example of such a tumor is malignant poroma) and primary cancers (e. g., mucoid adenocarcinoma). Cancers of the first group, which comprise a majority of all SGC, run a more favorable course.

[Unusual (epithelioid) leiomyoblastoma of the stomach]. / Prichudlivaia (épitelioidnaia) leiomioblastoma zheludka.

The authors present clinical and morphological characteristics of gastric leiomyoblastoma (25 cases) nominated by Soviet investigators as a myoid or angioleiomyomatous variant of a glomus tumor. The tumor was composed of leiomyomatous sites, clusters of epithelioid cells with apparently empty cytoplasm and frequently odd nuclei. Morphological criteria are suggested referring leiomyoblastoma to mature, infiltrative and malignant. Electron-microscopic examination in 8 cases provided evidence for myogenic origin of the neoplasm. Smooth muscle differentiation is shown to resolve with growing of cell proliferation and relevant atypia.

[Electron-microscopic study of myogenic neoplasms]. / Elektronno-mikroskopicheskoe issledovanie miogennykh novoobrazovanii.

Electron microscopic study of leiomyoma of skin arteries, oesophagus leiomyoma, leiomyosarcoma and rhabdomyosarcoma was carried out. In the tumor cells myofilaments were found sometimes forming hexagonally packed myofibrilles, formations resembling desmosomes. This permitted the establishment of valid myogenic histogenesis of these neoplasias.

[Ultrastructure of malignant fibrosarcoma]. / Ul'trastruktura zlokachestvennoi fibrosarkomy.

Electron microscopic examinations of two malignant fibroxanthomas revealed some ultrastructural features characteristic of this tumor. The tumor elements were represented by histiocyte-like, fibroblast-like and little differentiated cells. In some of the latter the signs of macrophage differentiation could be seen and therefore a possibility of their transformation into histiocytes is assumed.

[Ultrastructural features of fibrosarcoma]. / Ul'trastrukturnye osobennosti fibrosarkomy

An electron-microscopy investigation of two fibrosarcomas was carried out. Blastomatous elements were represented by fibroblasto-like cells. In their cytoplasm there were observed phaged fragment of collagenic fibrils, and in small canals of the granular endoplasmic reticulum--crystalloid formations. Diagnostic significance of these findings is discussed.

[Peripheral nerve ectomesenchymoma (neuroectomesenchymoma): a malignant tumor made up of neural crest elements]. / Ektomezenkhimoma (neiroéktomezenkhimoma) perifericheskogo nerva: zlokachestvennaia opukhol' iz élementov nevral'hogo grebeshka.

Characteristics of a little-studied tumor of soft tissues are described on the basis of the author's own material (4 observations) and data from the literature. The matter at issue is a benign or malignant schwannoma (less frequently, ganglioneuroblastoma) in which there are areas of rhabdomyosarcoma and sometimes tumor elements of mesenchymal origin (angio- lipo-, or osteogenic sarcoma). As a rule, this tumor is located along the peripheral nerve or arises in one of the nodes in Recklinghausen's disease and has a trend to hematogenic metastasising. It is suggested that the source of growth of neoplasias of this kind are the cells of "neural crest" migrating in the process of embryogenesis. These cells are responsible for the formation of lemmocytes, ganglial elements and melanocytes, as well as ectomesenchyma from which, in its turn, a part of cross-striated musculature is formed. Therefore, the tumors described in the paper should be designated as "neuroectomesenchymoma" (according to some authors, ectomesenchymoma).

[Morphology and histogenesis of soft tissue chordoid sarcoma]. / O morfologii i gistogeneze khordoid-sarkomy migakikh tkanei.

The data of examinations of 6 chordoid-sarcomas of soft tissues which, owing to myxomatosis of the interstitial substance and vesicle-like cells containing glycogen, are similar in structure with skeletal chordoma are presented. It is emphasized that choroidsarcoma, unlike chordoma, has the ultrastructural features of cartilage differentiation: collagenization of the matrix, similarity of some tumour cells to chondrocytes. These data suggest that chordoid-sarcoma is histogenetically associated with rudiments of mesenchyma responsible for cartilage formation.

[Alveolar soft tissue sarcoma]. / Al'veoliarnaia miagkotkannaia sarkoma.

Clinical and morphological manifestations of alveolar soft tissue sarcoma (ASTS) are presented on the basis of 19 examinations performed by the authors and data available in the literature. ASTS has been found to be more common in young women and to be usually located in the thick layers of the proximal parts of the extremities. The tumor generally shows slow growth and late occurrence of metastases. It has been demonstrated that ASTS has an organoid structure, namely alveolar grouping of cells, abundance of capillaries, and its cells contain PAS-positive inclusions. In atypical ASTS, the prognosis has been found to be less favourable. The crystalloid inclusions that are absent in other soft tissue neoplasms are a characteristic ultrastructural sign of ASTS. The genesis of ASTS remains controversial but it cannot be ruled out that it is related to the elements of the APUD-system.

[Mesenchymal chondrosarcoma of soft tissues]. / Mezenkhimal'naia khondrosarkoma miagkikh tkanei.

Clinical and morphological data on 2 observations of soft tissue mesenchymal chondrosarcoma (both in women) are given. In one case the primary tumour was localised in the soft tissues of the posterior part of the hip with subsequent metastasis into the lungs and the soft tissues of the head. In other case the tumour was localised in the soft tissues of the leg and no metastasis was detected. The correct diagnosis was established after histological examination only.

[Acrospiroma (clinico-morphological characteristics and histogenesis)]. / Akrospiroma (kliniko-morfologicheskaia kharakteristika i gistogenez).

Clinico-morphological characteristics of 105 acrospiromas surgically removed within 10 last years is presented. In 6 patients the tumour was considered as a malignant acrospiroma which, according to the literature and the authors' material, is prone to recurrence. The features of a diagnostic significance are discussed in detail: the development of tumour in the cyst, growth of squamous cells and clear (due to the glycogen) cells, formation of structures resembling the sweat glands ducts. Electron-microscopic examination indicates the histogenetic link of acrospiroma with the elements of sweat gland ducts (intracytoplasmic ducts, periluminal cells, the lack of clear signs of secretion). All this relates also to the tumour described in the literature as a clear-cell hydradenoma.

[Spindle-cell thymoma (a histological and electron microscopic study)]. / Veretenokletochnaia timoma (gistologicheskoe i elektronno-mikroskopicheskoe issledovanie).

The paper describes 12 cases of spindle cell thymoma without myasthenia or any other syndromes such as hypogammaglobulinemia, hypoplasia of the red sprout of the bone marrow. In most patients the tumours were detected roentgenologically. Microscopic diagnosis of spindle cell thymoma is based on the detection in it of epithelial cell structures. In those cases where the tumours were represented by spindle cells alone, verification of the tumor was possible only by electron microscopic studies (the presence in the cells of tonofilaments, desmosomes and basal membrane).

[Pathological anatomy of thymus gland tumors]. / Patologicheskaia anatomiia opukholei vilochkovoi zhelezy.

The paper presents detailed morphological characteristics of 31 thymomas and 25 microscopically similar neoplasias of the anterior mediastinum (carcinoid, seminoma, lymphogranulomatosis, angiofollicular lymphoma, etc). The term "thymoma" is determined as a tumour consisting of two components: mandatory epithelial one and lymphocytes. The diversity of the morphological picture of thymomas is determined mainly by the variability of the epithelial component. The special features of the ultrastructural organization of thymomas (the presence of desmosomes, tonofibrils and basal membrane) were revealed which facilitate the differential diagnosis of the anterior mediastinum tumours.

[Lymphogranulomatosis of the thymus gland ("granulomatous thymoma")]. / Limfogranulemotoz vilochkovoi zhelezy ("granulematoznaia timoma").

Thirteen tumors of questionable genesis located in the thymus were studied. The microscopical structure of these tumors was identical to lymphogranulomatosis of other localization. Reactive proliferation of the thymic epithelium and cyst formation are characteristic of lymphogranulomatosis primarily developing in the thymus. The disease was not "granulomatous thymoma" since giant multinuclear cells by their structural characteristics corresponded to reticular elemens and the epithelial component was absent in extrathoracal formations.

[Differential diagnosis of epithelial thymoma and seminoma (histological and electron-microscopic study)]. / K voprosy o differentsial'noi diagnostike epitelial'noi timomy i seminomy.

The paper describes two observations of thymus gland tumours: epithelial thymoma and seminoma. Differential diagnosis of these tumours is very important for the proper selection of the method of treatment as seminoma is more radio-sensitive than epithelial thymoma. Epithelial thymoma is characterized by coarse-fiber stroma, perivascular grouping of cell elements and the lack of glycogen in them. Seminoma consists of light and dark cells containing much glycogen in their cytoplasm. Differences between these tumours are most clearly seen in electron microscopic studies. In epithelial thymoma cells have processes, numerous tonofilaments, desmosomes, and basal membrane. Seminoma cells contain glycogen, no tonofilaments or basal membrane, few desmosomes.

[Tumors developing in an epidermal cyst]. / Opukholi epidermal'noi kisty.

The paper presents clinical and morphological characteristics of neoplasms arising in epidermal cysts (73 observations). It is emphasized that the epithelium of epidermal cyst may be the source of growth of not only benign cystic epithelioma ("proliferating epidermal cyst" as designated by the foreign authors) but also of squamous cell carcinoma. Cystic epithelioma (54 observations) is a slowly growing tumor represented by outgrowths in the cyst lumen of differentiated squamous epithelium apt to form smaller cysts. A predominance in cystic epithelioma of the basal type cells and complexes of squamous epithelial cells with hyperchromic and slightly polymorphous nuclei (7 observations) is considered to be the initial sign of malignancy of the noninvasive cancer type. Cancer arising in epidermal cyst (11 observations) is characterized by rapid growth, invasion into derma and trend for relapses. Frequently it has the structure of keratinizing squamous cell carcinoma. A malignant tumor is described characterized by a combination of cystic epithelioma, squamous cell carcinoma of pseudosarcomatous structure in some areas and glandular formations whose origin is obscure.

[Epidermoid thymoma--a variety of thymus gland cancer]. / Epidermoidnaia timoma--raznovidnost' raka vilochkovoi zhelezy.

Epidermoid thymoma was referred to thymal malignancies after an evaluation of the data on its clinical course and microscopic structure. This tumor may be diagnosed preoperatively on the basis of an analysis of clinico-roentgeno-endoscopic data and findings of a cytological, histological and electron-microscopic examinations.

[Electron microscopy diagnosis of soft tissue sarcoma]. / Elektronno-mikroskopicheskaia diagnostika sarkom miagkikh tkanei.

The results of electron microscopy studies of 20 soft tissue sarcomas difficult to diagnose-fibrosarcomas, malignant fibroxanthomas, leiomyosarcomas, rhabdomyosarcomas and malignant schwannomas, are reported. The tumor elements of each of these neoplasms showed rather typical ultrastructural features enabling us to reliably ascertain their histological origin.