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Biomedical subjects

M Michal

Publications and source records attributed to M Michal.

At least 181 records · Page 10Linked to original sources
PubMed1994

Spindle cell tumor of lymph node of probable reticulum cell origin associated with multiclonal gammopathy.

We describe a case of a 48 year old man who presented repeatedly with a neck lymph node tumor. The tumor grew insidiously over 11 years and the patient died at the age of 58 with the generalization of the tumor into the right cervical, paratracheal lymph nodes and spleen. The tumor was composed of spindle shaped cells with occasional intranuclear cytoplasmic pseudoinclusion. At the ultrastructural level the tumor revealed membrane bound crystalline inclusions, which were locally in direct contact with both the nuclear envelope and confronting cisternae of the endoplasmic reticulum. The tumor was associated with multiclonal gammopathy composed of two subsets of IgG/lambda and one subset of IgA/lambda positive paraprotein produced by lymphoid cells surrounding the tumor. We diagnosed the tumor as "spindle cell tumor of lymph node of probable reticulum cell origin associated with multiclonal gammopathy" and consider the lymphoid tissue producing the paraprotein to be reactive.

Autopsy↗
PubMed1994

[Angiomyofibroblastoma of the lower genital tract in women].

Angiomyofibroblastoma (AMF) was described recently as a benign tumour with histology very similar to pelvic aggressive angiomyxoma (AMM). Cases from vulva and scrotum are known for the time being. Two cases of AMF were presented, one quite unusual from vaginal portion of uterine cervix. Both cases had typical histology with biphasic structure of proliferating vessels with various diameter and of stromal myofibroblasts with a desmin positive and actin negative immunophenotype. The same expression was found in subepithelial connective layer of vaginal mucosa which is supposed to be the source of AMF. A close histogenetic relation of AMF and AAM was discussed because of their lightmicroscopical and immunohistochemical overlapping.

Adult↗
PubMed1994

[Bimorphic malignant lymphoma].

Two distinct morphological types of malignant lymphoma in the same patient occur mostly due to transformation of a low-grade lymphoma to high-grade lymphoma. When two morphologically different structures are found at different sites they represent discordant lymphoma. Composite lymphoma, on the other hand, shows two histologic subtypes involving the same location. Bimorphic morphology of malignant lymphoma is of therapeutic and prognostic significance.

Hodgkin Disease↗
PubMed1993

Aggressive angiomyxoma of the pelvioperineal region. Immunohistological and ultrastructural study of seven cases.

We describe seven cases of aggressive angiomyxoma of the pelvioperineal region. In three cases, we observed immunohistochemical signs of myoid differentiation in the tumor cells. In one of these cases, we could confirm the myoid differentiation at the ultrastructural level. The other four cases were devoid of this differentiation. We further discuss the relationship of aggressive angiomyxoma to the recently described angiomyofibroblastoma of the vulva.

Actins↗
PubMed1993

Littoral cell angioma of the spleen. A case report with ultrastructural and immunohistochemical observations.

We describe histological, immunohistochemical and ultrastructural findings in a case of littoral cell angioma of the spleen in a 44 year old man. Beside phagocytosis and heavy haemosiderin deposits in the cytoplasm, a very characteristic and hitherto undescribed feature of the littoral cells was focal accumulations of eosinophilic globules 0.5-2 microns in size, which often entirely filled the cytoplasm of the tumour cells. Ultrastructurally the globules were composed of abundant cytoplasmic deposits of lysosomes and residual bodies. The globules most probably originate from the phagocytized red blood cells, lymphocytes and plasma cells. Immunohistochemically the tumour cells reacted positively with antibodies against factor VIII-related antigen, KiM1P, KP1 and lysozyme and negatively with antibodies against cytokeratins AE1-AE3, EMA and S-100 protein. Ultrastructurally the tumour cells often formed long cytoplasmic processes without external lamina and pinocytic vesicles. Scarce and poorly formed junctions between the tumour cells were seen. Very rarely cytoplasmic rod-shaped microtubulated bodies, often difficult to distinguish from heavy accumulations of lysosomes were observed.

Adult↗
PubMed1993

Mixed medullary-follicular and medullary-papillary carcinoma of the thyroid: one or two entities?

Among 36 cases of medullary carcinoma of the thyroid we found two cases of mixed medullary-follicular carcinoma which in addition to the typical morphology contained foci of clear cells with cytological features of papillary carcinoma of the thyroid. The authors compare the two cases with the recently described entity called medullary-papillary carcinoma of thyroid.

Adenocarcinoma, Follicular↗
PubMed1993

Myxoid variant of dermatofibrosarcoma protuberans with fibrosarcomatous areas.

A case of dermatofibrosarcoma protuberans in a 39-year old woman excised from the right subclavicular region is described. Beside the typical storiform cellular pattern characteristic of dermatofibrosarcoma protuberans, a considerable part of the tumour displayed a myxoid change. Another part of the tumour exhibited large areas with a fibrosarcoma-like pattern. The transitional areas between these myxoid and fibrosarcoma-like areas resembled a poorly differentiated spindle cell sarcoma. Two years later the tumour recurred. The remarkable feature of the recurrent tumour was the occurrence of multiple giant cells identical to those seen in giant cell fibroblastoma.

Adult↗
PubMed1993

Glomus tumour with intravascular spread.

We present here a case of 48 year-old man with a glomus tumour on the dorsal side of the right foot which displayed intravascular spread of the tumour cells. Four years after excision the patient was without recurrences and metastases. Intravascular spread of tumour in our case can be compared with the same phenomenon in intravascular leiomyomatosis. We do not consider such spread in glomus tumour as a sign of malignancy.

Blood Vessels↗
PubMed1993

[Collagenous crystalloids and collagenous spherules in salivary gland tumors. A light microscopy and immunohistochemistry study].

In a series of 354 salivary gland tumors, the morphological and immunohistochemical study of two distinctive types of extracellular matrix deposits was carried out. First, collagenous crystalloids, distinct spherical crystalloids composed of radially arranged needle-shaped collagen fibres, were found in twelve cases of benign salivary gland tumors. Second, collagenous spherules, globoid structures often showing concentric lamellar or radial pattern, were found in 46 cases of both benign and malignant salivary gland tumors. Immunohistochemically, collagenous crystalloids and collagenous spherules contain varying amounts of type I and III collagens, proteoglycans and elastic fibres but not collagen types II and VI. Strong linear deposition of basement membrane proteins, collagen type IV and laminin, surrounded collagenous spherules. Discontinuous patchy deposits of both proteins were, however, found near collagenous crystalloids. The cells surrounding these collagenous crystalloids and collagenous spherules showed immunohistochemical and morphological features of modified myoepithelial cells. Our observations may improve a terminology of the structures in question. Proposed active role of modified myoepithelial cells in the origin of these extracellular deposits still remains open for discussion.

Collagen↗
PubMed1993

Palisaded intranodal myofibroblastoma. Electron microscopic study.

Described in this paper are the ultrastructural features of three cases of palisaded intranodal myofibroblastoma. The tumor cells were identified as myofibroblasts. Abortive vessels formed by the tumor in one case and spindle cell tumorous proliferation outside the tumor capsule and centered on the veins were composed of the same cell types as the cells of the main tumor mass, suggesting that the tumorous myofibroblasts might have originated from the modified smooth muscle cells. The various stages of formation of the intracytoplasmic fuchsinophilic bodies are described in our report.

Collagen↗
PubMed1993

Diffuse sclerosing variant of papillary thyroid carcinoma.

Five cases of the diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) were presented. The fifth case was discovered in a statistically not defined series of carcinomas of the thyroid gland. DSPC were found in 5.7% of 70 cases of thyroid papillary carcinoma. All the cases described showed a similar histological picture. In the first case a "dominant nodule" was found. Immunohistologically B-cell markers were mostly proved on lymphocytes of the focal lymphocytic infiltration. Accumulation of Langerhans cells was present in the tumour foci. The finding of these cells is regarded as a sign of an enhanced immunological defense mechanism. The clinical follow-up interval of patients was 3 to 9 years. Less favourable prognosis of DSPC as compared with classical papillary carcinomas could not be confirmed in this series.

Adolescent↗
PubMed1993

Nerve-like myoid differentiation in sclerosing adenosis of breast. A diagnostic pitfall.

A surgically excised lesion from the breast of a 33 year old woman showed apart from cystic disease sclerosing adenosis with distinct myoid differentiation. The myoid bundles were wrapped around original ductules producing a misleading picture which simulated tangentially cut nerves, infiltrated by tumour glands. Immunohistochemically, actin positivity and S-100 protein negativity confirmed the nature of the lesion as sclerosing adenosis.

Adult↗
PubMed1992

Collagen composition and ultrastructure of the so-called amianthoid fibres in palisaded myofibroblastoma. Ultrastructural and immunohistochemical study.

A very prominent feature of the recently described intranodal palisaded myofibroblastoma is the occurrence of stellate crystalline extracellular deposits known as 'amianthoid fibres', and thought to represent abnormally thick collagen fibrils. We showed at the ultrastructural level that these deposits are composed of fibrils with the periodicity and width typical of normal native collagen. Using antibodies directed against various extracellular components, we have determined that these structures contain type I and III collagens. Our results indicate that the crystalloid deposits in intranodal palisaded myofibroblastoma called 'amianthoid fibres' do not contain giant collagen fibrils widely regarded as characteristic of the morphological concept 'amianthoid' in other locations.

Cartilage↗
PubMed1992

Analysis of collagen isotypes in crystalloid structures of salivary gland tumors.

Extracellular collagenous crystalloids (CCs) have been reported in salivary gland tumors. To study the occurrence and characteristics of these structures we reviewed 230 pleomorphic adenomas and myoepitheliomas of both major and minor salivary glands. Twelve of these cases contained crystalloids composed of radially arranged collagen fibers. However, no CCs were found in 124 malignant salivary gland tumors of different types. We show that CCs contain types I and III collagen but not type II, IV, or VI collagen. Moreover, cells surrounding CCs expressed the basement membrane molecules laminin and type IV collagen. These cells also showed other immunohistochemical features typical of myoepithelial cells.

Adenoma, Pleomorphic↗
PubMed1992

Intranodal "amianthoid" myofibroblastoma. Report of six cases immunohistochemical and electron microscopical study.

Six cases of intranodal amianthoid myofibroblastomas are reported. Immunohistochemically the tumors were actin positive and S-100 protein and desmin negative. Intracytoplasmatic, actin-rich bodies, previously found to be a characteristic feature of this tumor, were identified as cytoplasmatic extensions filled with microfilaments at an ultrastructural level. Abortive vessel formation by the tumor cells and the proliferation of tumor cells centered on veins outside the capsule of the tumor in two of our cases indicated a close relationship between the intranodal palisaded myofibroblastoma and the musculature of vascular origin.

Groin↗