[Sygmoid endometriosis].

A case of sygmoid endometriosis is described in a 40-year-old female. After clinical and endoscopic examination, the patient was operated for sigmoid tumor, acute obturation colon obstruction. Histologically diagnosis of intestinal wall endometriosis was established. This is an example of therapeutic policy in extragenital intestinal endometriosis with difficulties in the clinical diagnosis.

[Intraductal intraepithelial neoplasia and ductal pancreatic carcinoma].

The review of modern achievements in morphology and genetic characteristics of pancreatic tumors with ductal phenotype is presented. Problems of intraductal pancreatic neoplasia (PanIN) as precancerous process for ductal adenocarcinoma are considered in detail.

[Classification of pancreatic exocrine tumours].

Current international histologic classification of exocrine pancreatic tumours is presented. Macro- and microscopic characteristics of benign and malignant tumors are described. The role of immunohistochemistry in differential diagnosis is shown.

[Monoclonal antibody therapy with mabtera of patients with b-cell low grade non-Hodgkin's lymphoma].

The data on monoclonal antibody monotherapy (mabtera, rituximab) in 44 patients with B-cell low grade non-Hodgkin's lymphoma were assessed. Thirty-four of them had received several courses of second- or third line chemotherapy: mabtera was used as first-line therapy in 10. Mabtera was administered in a dose of 375 mg/m2 body surface, once a week, by slow intravenous infusion, 4-14 times depending on effect. Each relapsing patient received, on the average, 4 infusions, while each refractory one--8 weekly infusions. Overall response in the first group was 44%. Median overall relapse-free survival was 9 months. Apparenti effect of treatment was reported in 50% of primary patients (median overall relapse-free survival--15 months). Therapy was well tolerated. Fever and shivering stage I and II were among the most frequent post-infusion effects. High level of CD-20+B-lymphocytes should be used as prognostic indicator for effectiveness of therapy.

[Histological and ultrastructural characteristics of morphological variants of neurilemmoma]. / Gistologicheskie i ul'trastrukturnye osobennosti morfologicheskikh variantov nevrilemmomy.

On the basis of histological and ultrastructural study of 57 neurilemmomas 4 main morphological types of tumour are distinguished; with a prevalence of the Antoni A type tissue, with a prevalence of the tissue of the transitory zone, prevalence of the Antoni B type tissue and a fibrosing variant of neurilemmoma. A variety of the morphological variants of neurilemmoma is due to different quantitative combination of morphological sings of degeneration and necrosis of tumour cells with the organization of the aseptic necrosis of tumour cells with the organization of the aseptic necrosis by their replacement with a fibrous tissue. The peculiarity of the peripheral nerve blood supply is a premise for the development of tumour cell degeneration.

[Lymphangioleiomyomatosis of the retroperitoneal space]. / Limfangioleiomiomatoz zabriushinnogo prostranstva.

The clinical course and the results of histological examination of retroperitoneal lymphangioleiomyomatosis in a woman of 32 are presented. The main morphological features of the disease were as follows: localization of tumour cells around the vascular spaces, accumulation of mature lymphocytes in the vascular spaces and among tumour cells, pronounced argyrophilic carcass of the tumour.

[Comparative ultrastructural characteristics of epithelial cells of the parenchyma of the thymus gland and thymoma]. / Sravnitel'naia ul'trastrukturnaia kharakteristika épitelial'nykh kletok parenkhimy vilochkovoi zhelezy i timom.

Comparative ultrastructural investigation of the parenchyma was performed for human thymus (7 specimens) and thymoma (34 specimens). For thymic parenchyma eight types of epithelial cells were identified. These may be represented by three different histogenetic lines: 1) spindle-shaped appendiceal cortical cells (type 1-4) 2) medullary cells showing signs of squamous-epithelium differentiation (type 5-6) 3) medullary cells with signs of glandular differentiation (type 7-8). Thymomas demonstrated cells ultrastructurally similar to thymic parenchyma and exhibiting features of either cortical or medullary epithelial cells. These findings served the basis for dividing thymomas into 3 major groups: 1) with cortical cell differentiation 2) with cortical and medullary cell differentiation 3) with medullary cell differentiation.

[A nevus comprised of balloon-like cells]. / Nevus iz ballonoobraznykh kletok.

Histologic and ultrastructural findings made in a case of this rare tumor of melanocytic origin are described in detail.

[Benign cystic mesothelioma of the peritoneum]. / Dobrokachestvennaia kistoznaia mezotelioma briushiny.

Histological, histochemical and ultrastructural analysis of a rare benign tumour of peritoneum, called "cystic mesothelioma", is performed. Cystic mesothelioma is characterized histologically by a combination of cystic, papillary and adenomatoid structures; mesothelial cell signs are seen ultrastructurally.

[Histological and ultrastructural characteristics of Abricosov metastasizing tumor]. / Gistologicheskie i Ulstrastrukturnye osobennosti metastaziruiushchei opukholi Abrikosova.

An observation of granular cell Abrikosov tumor metastasizing into lymph nodes is presented. The diagnosis was confirmed by electron microscopy. The ultrastructural features of the tumor confirming its neurogenic origin are described. This is indicated, in particular, by the similarity of the tumor cells with lemmocytes, detection of a basal membrane in some of them, as well as the presence of axonlike projections. The content of some cytoplasmic inclusions was found to be an accumulation of microtubules.

[Abrikosov's tumor]. / Opukhol' Abrikosova.

Histologic and ultrastructural features of 11 Abrikosov's tumors located in various sites are described. They all had similar structures and comprised tumor cells of two kinds, polygonal and spindle-shaped. Both contained dark as well as clear cells that differed in the composition and number of cytoplasmic inclusion bodies and glycogen granules. Three types of specific cytoplasmic bodies were identified. Type 1 bodies had a peculiar shape resembling a tennis racket; type 2 were round, tended to fuse with one another, were intimately linked up with the endoplasmic reticulum, and bore structural similarity to Berbek's granules in Langerhans cells; while type 3 bodies were larger than the other types and ellipsoid in shape. The authors suggest on the basis of their findings that Abrikosov's tumor cells are related histogenetically to Langerhans cells.

[Metaplasia and dysplasia of thymus gland epithelium]. / Metaplaziia i displaziia épiteliia vilochkovoi zhelezy.

Morphology of the thymus in autoimmune and some other conditions with an accidental thymus involution is studied. Metaplasia and dysplasia of epithelial cells which should be regarded as precancer condition were found in 7-10% of cases in the parenchyma in the presence of atrophic changes.

[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.

[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.

[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.

[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).

[Diagnosis of epithelioid sarcoma]. / O diagnostike épitelioidnoi sarkomy.

Epithelioid sarcoma is a rare soft tissue tumour. Small-nodular structure, necrotic foci in the centre of tumour nodes, moderate lymphocytic infiltration are characteristic histologic features of this tumour. Majority of tumour cells have the appearance of epithelioid histiocytes. Some tumour cells are found in small cavities resembling hyalin cartilage lacunes. Signs of a synovial, fibroblastic and histiocytic differentiation are observed ultrastructurally in the epithelioid sarcoma cells On the basis of the literature analysis and their own ultrastructural data the authors conclude that there should be a relation of this tumor with pluripotential stem cells of mesenchyma surrounding distal part of the chondral bone germ.

[Morphological diagnosis of Lennert lymphoma]. / O morfologicheskoi diagnostike limfomy Lennerta.

Two observations of Lennert lymphoma are described. The cytological and histological diagnosis of the disease was established after examination of cervical and axillary lymph nodes on the basis of combination of the following features: multiple tubercle-like aggregates of epithelioid cells and large atypical histiocytes, marked malignant transformation of both large and small lymphoid cells, infiltration of the lymph node capsule and extranodal tissue with atypical lymphocytes and histiocytes, the absence of Berezovsky-Sternberg cells.

[Morphology and histogenesis of paraganglioma]. / Morfologiia i gistogenez paragangliomy.

Histological and ultrastructural studies were performed to examine 6 paragangliomas of various sites: carotid glomus, aortic body, sympathetic chain, and stomach. Five of the tumors in question had a histological structure typical of a paraganglioma. The gastric tumor was distinguished by being similar to a pheochromocytoma. With regard to the degree of infiltrative growth, the paragangliomas of the sympathetic chain and stomach were regarded as malignant. The ultrastructures of the paragangliomas examined were found to be of the same type. In all the neoplasms, tumor cells had signs of neuroendocrine and neurogenous differentiations that were characteristic of the ultrastructural organization of postganglionic neurons in the autonomic nervous system. The neurogenous differentiation was evidenced by cytoplasmic portions that are structurally similar to rough-surface endoplasmic reticulum, which is pertaining to Nissl's bodies; neurofilaments that form concentric structures containing neuroendocrine granules such as fibrous or Pick's bodies; intracytoplasmic cilia; specialized cytoplasmic processes of two types: axons and dendrites; partially reduced intercellular contacts, such as axosomatic and axodendritic synapses; sustentacular cells (sustenocytes). In the neoplasms evaluated as malignant, the neurogenous differential signs were more pronounced by reducing the number of neurosecretory granules, which might, apparently, serve as an ultrastructural criterion for establishing the degree of paraganglioma malignancy.

[Benign tumors of the peripheral nerve sheaths]. / Dobrokachestvennye opukholi iz obolochek perifericheskikh nervov.

Benign tumors from sheaths of peripheral nerves (25 neurolemmomas and 6 neurofibromas) were studied. The ultrastructural data presented attest to the principal differences between these tumors and the possibility of their differential diagnosis. The typical signs of tumor cells of neurilemmoma include numerous complicatedly interwoven processes not infrequently forming " pseudomesaxonal " structures, and the presence of permanent basal membrane. These signs indicate the histogenetic relationship of neurilemmoma with cells of the Schann sheath of the peripheral nerve ( lemmocytes ). Neurofibroma tumor cells were characterized by the presence of bipolar thin, long non-interwoven cytoplasmic processes with inconstant basal membrane, desmosome-like contacts between the processes, and pinocytic vesicles in the cytoplasm. The revealed ultrastructural signs indicate the histogenetic relationship of neurofibroma with cells of the perineurium of peripheral nerves.