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Biomedical subjects

M Michal

Publications and source records attributed to M Michal.

At least 127 records · Page 7Linked to original sources
PubMed1998

Endometrial stromal nodule with retiform sex-cord-like differentiation.

We describe an interesting case of uterine stromal nodule with sex-cord-like differentiation of retiform type. The tumour occurred in a 51-year-old woman. It contained areas of retiform patterns mimicking an epithelial component of some of mullerian biphasic tumours. Areas of classical sex-cord-like and smooth muscle differentiations were also found. The sex-cord-like cells revealed a smooth muscle phenotype in ultrastructural and immunohistochemical studies.

Actins↗
PubMed1998

Inflammatory myxoid tumor of the soft parts with bizarre giant cells.

We present five cases of a tumor which we named inflammatory myxoid tumor of the soft parts with bizarre giant cells and which is often misdiagnosed as a malignant neoplasm. The tumors were located in the soft tissues of the fingers and hand and were 1 to 2.5 cm in the largest diameter (median 2 cm). The tumors were divided by fibrous septa into lobules. The lobules were composed of numerous proliferating capillaries and tumor cells, both set in copious myxoid extracellular matrix. Variously dense inflammatory infiltrate represented by numerous lymphocytes and plasma cells and sparse neutrophil leukocytes surrounded the capillaries. The tumor cells had one, two, or more nuclei. The nuclei of the tumor cells were vesicular, often indented or cleaved and they usually had one small nucleolus. The cytoplasm displayed characteristic clear vacuoles filled with mucous substances. In some of the tumor cells the cytoplasmic vacuoles filled the whole cytoplasm and compressed or indented the nucleus. Such cells had an appearance of signet ring cells. The cytoplasm of some of the cells often contained lymphocytes and leukocytes. All four patients with follow-up were without signs of recurrence and metastasis 2, 4, 6 and 7 years after the diagnosis.

Adult↗
PubMed1998

Hyalinizing spindle cell tumors with giant rosette-like structures.

We report two cases of hyalinizing spindle cell tumors with giant rosettes arising in the pararectal space and soft tissues of the wrist in a 46-year-old man and 22-year-old-woman, respectively. Microscopically, the tumors exhibited a varied morphology, including hyalinizing hypocellular and cellular fibromatosis-like areas. The most striking morphologic feature was the formation of giant rosette like structures with collagen cores scattered throughout the tumors. Most of the tumor spindle cells were diffusely immunoreactive for lysozyme, CD-68, factor XIII and vimentin. Reactivity for smooth muscle actin, desmin and S-100 protein was not found. Ultrastructural examination of the rosettes in one case only showed normal native collagen.

Adult↗
PubMed1998

Cellular blue naevi with microalveolar pattern--a type of naevus frequently confused with melanoma.

We report on nine cases of cellular blue naevi with distinctive arrangement of cells into the microalveolar pattern. This microalveolar pattern was usually seen in the deeper parts of cellular blue naevi and was composed of a few epithelioid cells surrounded by bipolar dendritic pigmented cells. This unusual pattern often reminded of incipient malignant change within cellular blue naevi.

Adolescent↗
PubMed1998

Pigmented microcystic chromophobe cell carcinoma: a unique variant of renal cell carcinoma.

Five cases of pigmented chromophobe renal cell carcinoma are presented. The patients included four men and one woman between the ages of 60 and 73 years (median age, 66.5 years), who presented with symptoms due to their renal mass. Surgical resection of the renal mass was performed in all patients. Grossly, the tumors were well encapsulated, yellow to dark gray, with a vague nodular pattern on cut surface. The tumors varied between 2.5 and 9 cm in greatest diameter. Histologically, all tumors shared similar features, namely, a malignant cellular proliferation composed of deeply eosinophilic to clear cytoplasm with round nuclei and inconspicuous nucleoli. The cellular proliferation was arranged in a microcystic and/or microalveolar pattern. In one tumor, conventional areas of clear cell carcinoma in association with the chromophobe component were present. In addition, all tumors contained pigmented areas, which were shown by light microscopy to have features of lipochrome pigment. Ultrastructural studies of these areas demonstrated the presence of intracytoplasmic polygonal to round, electron-dense pigment granules, which in some areas seemed to coalesce to form larger granules. In addition, numerous mitochondria and cytoplasmic vesicles were present. The cases described herein highlight an additional morphologic variant of chromophobe renal cell carcinoma.

Aged↗
PubMed1998

Glassy hyaline globules in granular cell carcinoma, chromophobe cell carcinoma, and oncocytoma of the kidney.

The presence of glassy hyaline globules (GHG) in renal carcinomas has been rarely emphasized in the literature. We studied the frequency of these globules in numerous renal carcinomas, including granular cell, mixed clear cell/granular cell, papillary renal cell, and chromophobe renal cell carcinoma, as well as oncocytomas. GHG are eosinophilic bodies in the hematoxylin-eosin stained sections with a size ranging from 1 to 30 micrometer and strongly positive with the periodic acid-Schiff (PAS) histochemical stain. Ultrastructurally, they are seen as amorphous secretion inside of the cisternae of the rough endoplasmic reticulum. GHG were found in 49 of 64 cases of granular cell and mixed clear cell/granular cell renal carcinomas and in 5 of 33 papillary renal cell carcinomas. No GHG were found in 22 cases of chromophobe cell carcinomas and 26 renal oncocytomas. Our findings suggests that GHG are a characteristic feature of granular cell carcinomas, mixed clear cell/granular cell renal carcinomas, and in a small minority of papillary renal cell carcinomas. In addition, it suggests that the presence of GHG in a renal cell tumor may be of aid for excluding a diagnosis of chromophobe cell carcinoma or oncocytoma.

Adenocarcinoma↗
PubMed1998

Synovial metaplasia in lipoma.

We present a unique case of a lipoma with widespread synovial metaplasia. A 52-year-old woman had a recurrence 1 year after excision of a subcutaneous lipoma of the neck. Histologically, the primary tumor was an ordinary lipoma. The recurrent tumor was a myxoid lipoma with synovial metaplasia. The synovial metaplastic process manifested as labyrinthlike clefts, which were lined by one or more synovial-like cell layers. Ultrastructurally, the synovial metaplastic cell had secretory, phagocytic, and fibroblastlike features.

Female↗
PubMed1998

Malignant adenomyoepithelioma of the breast with mixed osteogenic, spindle cell, and carcinomatous differentiation.

A 50-year-old woman had a malignant tumor of the left breast, which recurred twice, metastasized, and caused death after 39 months. Histologically, the original neoplasm and the first recurrence comprised an adenomyoepithelioma, in addition to a sarcoma composed of trabeculae of mature and immature bone, osteoid, and partly calcified, dense collagenous tissue. The trabeculae were lined by alpha-smooth muscle actin-positive mononuclear tumor cells, which also extended into the stroma. Similarly, scattered osteoclastlike, multinucleate giant cells were present in the stroma and in the region of the trabeculae. This same pattern of adenomyoepithelioma and osteosarcoma also was seen in the last recurrence, together with a proliferation of undifferentiated malignant spindle-shaped cells. The last biopsy also contained a separate small focus of invasive ductal carcinoma of usual type. It was concluded that this, apparently unique, tumor probably represented an adenomyoepithelioma in which a metaplastic sarcoma of osteogenic and undifferentiated types developed from the myoepithelial element, and in which a carcinoma developed from the epithelial component.

Actins↗
PubMed1998

Nodular mucinosis of the breast: report of three cases.

Three cases of nodular mucinosis of the breast are presented. They occurred in one male and two female patients. The patients had no signs of Carney's syndrome. All lesions were located under the nipple. They were poorly circumscribed and unencapsulated. They were soft and had a gelatinous consistency and white color. No patient had any evidence of recurrence or metastasis 6 months, 3 years and 6 years, respectively, after the surgical excision. The mucinous tissue consisted of acid mucopolysaccharides, which stained Alcian blue, Hale's colloidal iron positively, and they were periodic acid-Schiff (PAS) negative. Mucicarmine reaction was only faintly positive. The lesion should be distinguished particularly from mucocele-like lesions of the breast by the location, nodular arrangement, absence of accompanying ductal hyperplasia and staining properties of the mucous substances.

Adenocarcinoma, Mucinous↗
PubMed1998

Oncocytic cystadenoma of the parotid gland with prominent signet-ring cell features.

A case of distinctive benign cystadenoma of the parotid gland composed of several different morphological components is presented. The most conspicuous morphological component and the largest part of the neoplasm was represented by solid sheets of oncocytic cells surrounded by myoepithelial cell layer. Most oncocytic cells possessed large intracytoplasmic vacuoles with the nuclei displaced towards the periphery, imparting them with a striking signet-ring cell appearance. The size of the intracytoplasmic vacuoles ranged from 4 to 50 microm. Immunohistochemically these signet-ring cells lacked immunoreactivity for S-100 protein and cytokeratin but they strongly stained for antimitochondrial antibody 113-1. The present case illustrates an unusual, hitherto undescribed, morphological feature of benign oncocytic cystadenoma of the parotid gland.

Actins↗
PubMed1998

Composite tumor consisting of dermatofibrosarcoma protuberans and myxofibrosarcoma.

A unique case of a composite tumor consisting of dermatofibrosarcoma protuberans and low-grade myxofibrosarcoma is described. The myxofibrosarcoma component formed 70% of the lesion volume. Both components protruded above the skin, and equally both infiltrated the subcutaneous tissue in the base of the lesion. The interface between them was mostly sharp but some small areas of gradual transition were also seen. Beside fibrosarcoma arising in the dermatofibrosarcoma protuberans, myxofibrosarcoma seems thus to be another possible manifestation of the change into a more malignant tumor rarely seen in the dermatofibrosarcoma protuberans.

Aged↗
PubMed1998

[Solitary fibrous tumor (fibrous mesothelioma). Report of 2 cases in an extraserous location].

Two cases of extraserosal solitary fibrous tumour occurring in the orbit and in the meninx are described. The orbital tumour contained, besides the well known features of this entity, nuclear palisading resembling rudimentary Verocay bodies which are considered typical of nerve sheath tumours. In the meningeal case there was close resemblance to fibrous meningioma and meningeal haemangiopericytoma. However, the tumour cells in both cases were negative for immunohistochemical markers of neural and meningeal differentiation (S-100 protein, neuron-specific enolase, glial fibrilary acidic protein, myelinic basic protein, Leu-7, epithelial membrane antigen) and reacted diffusely with CD34, CD99 and vimentin. The finding of nuclear palisading in one case reflected the great morphologic variability of extraserosal solitary fibrous tumour and might be misinterpreted as a feature of neurogenic tumour.

Humans↗
PubMed1998

Desmoplastic ameloblastoma.

Two cases of desmoplastic form of ameloblastoma are reported. This tumor shows marked stromal desmoplasia and often scattered osteoplasia. The majority of stromal elements is represented by myofibroblasts. The epithelial component of this tumor is often scanty and different from epithelial islands of classic ameloblastoma. Pathological, immunohistochemical and radiological findings are described and the differential diagnosis of this tumor is discussed.

Adult↗
PubMed1997

[Importance of determination of proliferation markers and hormone receptors in breast carcinoma].

BACKGROUND: Cell cycle kinetic measures have been shown to have prognostic significance in breast cancer. The proliferative activity of tumors has been investigated with different approaches among which the use of monoclonal antibody MIB1 (against Ki-67 antigen) represents an easy and reliable means of assessing cell proliferation. The prognostic value of quantitative estrogen receptor (ER) and progesterone receptor (PR) immunohistochemical analysis has been also well established. This study was conducted in order to demonstrate our experience with an immunohistochemical detection of the markers of proliferation and hormone status in formalin-fixed paraffin-embedded samples of 1224 primary breast carcinomas. METHODS AND RESULTS: In this study, the proliferative activity of breast carcinomas was investigated using immunohistochemistry with the monoclonal antibody MIB1 (Immunotech). For a detection of ER and PR content in breast carcinomas, the antibodies ER1D5 (Dakopatts) and PR10A9 (Immunotech) were used. Immunohistochemical studies were performed on sections of formalin-fixed paraffin-embedded tissues using the antigen retrieval method with a microwave oven irradiation. The MIB1 index was related to the histologic grade of ductal invasive carcinoma (p < 0.001). The study also revealed a significant correlation of the MIB1 index with ER values in grade II (p < 0.1) and grade III (p < 0.001), but not in grade I of ductal invasive carcinoma. Prognostic value of an immunohistochemical analysis of the MIB1 proliferative index, ER and PR status was determinated in this study.

Adult↗
PubMed1997

Well-differentiated acinic cell carcinoma of salivary glands associated with lymphoid stroma.

In a multicenter study, 69 acinic cell carcinomas of the salivary glands were identified, of which 12 constituted what the authors believe to be a distinct subgroup. Their most noticeable feature was a dense lymphoid stroma with well-developed germinal centers, surrounding a sometimes scanty epithelial component, which in each case had a microcystic growth pattern. All these tumors were enveloped by a thin fibrous pseudocapsule, thus mimicking an intraparotid lymph node containing a metastasis. All 12 cases showed low MIB1 proliferative activity, with a mean index of 1.7% (range, 0.5 to 3.7). All patients remained well without recurrence or metastasis in followup periods of 19 months to 14 years. A second subgroup of nine acinic cell carcinomas also possessed a heavy lymphoid stroma with germinal centers, but its distribution was more patchy than in the first subgroup, and in addition, the fibrous pseudo-capsule was incomplete or absent. In each case the epithelial growth pattern was other than microcystic. These tumors had significantly higher MIB1 indices (mean, 17%; range, 3.4 to 45). In contrast to the first subgroup, only three of nine patients remained well with no further disease. The other six patients developed recurrences or metastases, and two died of disseminated cancer. In view of the clinical and pathological data, it is speculated that the tumor foci lacking lymphoid stroma in each of the second subgroup possibly represented a clone of high-grade malignancy arising within a low-grade acinic cell carcinoma with lymphoid stroma.

Adult↗
PubMed1997

Intrathyroidal lymphoepithelial cyst. A report of two cases not associated with Hashimoto's thyroiditis.

Two cases of intrathyroidal lymphoepithelial cyst are described. Both of them were solitary, one being found incidentally in a patient operated on for a multinodular goiter, the other being clinically obvious as a cold nodule. They exhibited features of cysts of branchial cleft origin, i.e. squamous cell lining epithelium and abundant lymphoid tissue with reactive germinal centers. The thyroid gland parenchyma showed a discrete lymphoid infiltration consistent with the diagnosis of focal lymphocytic thyroiditis. In the first case a single epidermoid solid cell nest was found. The histogenesis of intrathyroidal lymphoepithelial cysts remains unclear, but their origin from cystically degenerated ultimobranchial body remnants (solid cell nests) seems to be most probable. This assumption is supported by a similar immunohistochemical profile of solid cell nests and epithelial cells lining the cysts and also by the presence of one solid cell nest in the proximity to the cyst in one of our cases.

Adult↗