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M L Geerts

Publications and source records attributed to M L Geerts.

At least 19 recordsLinked to original sources
PubMed1992

Demonstration of clonal immunoglobulin gene rearrangements in cutaneous B-cell lymphomas and pseudo-B-cell lymphomas: differential diagnostic and pathogenetic aspects.

Twenty-five patients with a benign or malignant cutaneous B-cell lymphoproliferative disease, including seven cutaneous pseudo-B-cell lymphomas, eight primary cutaneous B-cell lymphomas (CBCL), and 10 secondary cutaneous B-cell lymphomas, were investigated for the presence of clonal immunoglobulin (Ig) gene rearrangements using Southern blot hybridization analysis. The selection of pseudo-B-cell lymphomas was based on the presence of polyclonal light-chain expression with immunohistochemical analysis. All cases of CBCL demonstrated monotypic light-chain expression or absence of detectable Ig on CD20+ B cells. Clonal rearrangements of one or more Ig genes were demonstrated in four of seven cases of cutaneous pseudo-B-cell lymphomas, six of eight cases of primary CBCL, and in all cases of secondary CBCL. The observation that cutaneous pseudo-B-cell lymphomas as defined by immunohistochemical criteria often contain occult monoclonal B-cell populations implies that differentiating between pseudo-B-cell lymphomas and CBCL is not always possible by means of gene-rearrangement analysis. These findings may support the concept that cutaneous pseudo-B-cell lymphomas and primary CBCL are part of a continuous and progressive spectrum of B-cell lymphoproliferative skin disorders.

Adult↗
PubMed1992

[Acute hemorrhagic edema in an infant].

The clinical and histological features of acute haemorrhagic oedema of childhood are discussed with reference to an actual case. Although closely related to Schoenlein-Henoch syndrome, it is considered a distinct entity, on the basis of the typical clinical picture and the excellent prognosis.

Capillaries↗
PubMed1991

Lectin binding patterns of human tissue mast cells indicate marked phenotypical diversity.

Glycoconjugate expression by human tissue mast cells (MCs) from various sources (including lymph nodes with signs of chronic non-specific lymphadenitis, skin lesions of urticaria pigmentosa, and bone marrow infiltrates associated with systemic mastocytosis) was studied histochemically with a broad panel of fluorescein-labelled lectins. Of the 19 lectins applied, 11 (sugar specificities: fucose, N-acetylgalactosamine and neuraminic acid) did not stain any MCs, while 8 (sugar specificities: mannose, N-acetylglucosamine, and galactose) were found to bind to MCs. These lectins exhibited different binding patterns in various disease entities. Only a few of these 8 lectins (in particular, phythaemagglutinin-L) produced strong staining of the MCs in most or all of the cases. Some (e. g. phythemagglutinin-E) produced only weak staining, and this in only a few cases. The lectins used, however, did not distinguish between reactive and tumorous MCs. Although lectins are therefore unlikely to be of use in resolving problems of differential diagnosis concerning proliferation of MCs, our investigation has shown that tissue MCs exhibit marked phenotypical diversity with regard to their lectin-binding properties.

Biopsy↗
PubMed1990

Use of monoclonal antibody KP1 for identifying normal and neoplastic human mast cells.

The monoclonal antibody KP1 (CD68) was used to stain normal and neoplastic monocytes and macrophages in routinely processed, paraffin wax embedded tissue: mast cells also exhibited strong, consistent cytoplasmic immunoreactivity. Light microscopic findings were corroborated by electron microscopical and immunocytochemical findings. The predominant sites of immunoreactivity were the specific intracytoplasmic granules of the mast cells. All mast cell subtypes--that is, normal and reactive mast cells, such as those in lymph nodes exhibiting chronic non-specific lymphadenitis, and malignant or neoplastic mast cells in various types of mastocytosis--reacted with this antibody. This finding is of diagnostic importance, because mast cell proliferation could be mistaken for histiocyte proliferation. It also supports the hypothesis that mast cells derive from the bone marrow.

Antibodies, Monoclonal↗
PubMed1990

Naevus sudoriferus.

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Abdominal Muscles↗
PubMed1990

Ashy dermatosis.

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Adult↗
PubMed1989

Prognostic significance of CD30 (Ki-1/Ber-H2) expression in primary cutaneous large-cell lymphomas of T-cell origin. A clinicopathologic and immunohistochemical study in 20 patients.

The histologic and immunophenotypical features of 20 primary cutaneous large-cell lymphomas of T-cell origin were investigated and correlated with clinical data to obtain prognostically relevant criteria. Histologic evaluation, using the updated Kiel classification, showed that these large-cell lymphomas represent a morphologic spectrum, often making classification rather arbitrary. It is therefore concluded that the clinical relevance of histologic subtyping is limited for this group of lymphomas. Immunophenotypical studies revealed significant differences between CD30-positive and CD30-negative lymphomas. CD30-positive lymphomas generally presented with localized skin disease, and had a favorable prognosis (9 of 10 patients alive and in complete remission; median survival, 37 months). In contrast, CD30-negative lymphomas often presented with or rapidly developed generalized disease; all patients died of lymphoma (median survival, 17 months). These findings suggest that CD30 expression is an important prognostic parameter for this group of primary cutaneous large-cell lymphomas.

Antigens, CD↗
PubMed1989

[Cutaneous burns caused by Yperite. Apropos of 2 new cases].

Based on two of their own cases, the authors review the lesions produced by Yperite. This chemical agent produces cutaneous burns which are quite characteristic; histological study of biopsies carried out on cutaneous lesions was used to define the effects on the epidermis and dermis. The treatment of patients, with this rare condition, remains symptomatic.

Adult↗
PubMed1987

Multiple clear cell acanthomas. A clinical, histological, and ultrastructural report.

A case of multiple clear cell acanthomas in a 64-year-old woman is reported. The clinical and histological findings of this rare entity are consistent with the hypothesis that clear cell acanthomas are benign epidermal tumors. An ultrastructural study was performed with special emphasis on the melanocytic-keratinocytic interaction.

Epidermis↗
PubMed1987

[Congenital diffuse melanosis].

Two cases of diffuse congenital melanosis are presented. The hyperpigmentation appeared shortly after birth and invades progressively the trunk and the limbs. It is diffuse and most intensive on the abdomen and the back, and reticulated on the neck, the genitals and in the groins. The nails are thin and their surface is slightly irregular. Histologic examination reveals the presence of melanin in the deep and superficial layers of the epidermis. On electron microscopy the melanosomes are not grouped within the keratinocytes, but are dispersed throughout the cytoplasm of the epidermal cells. The disease can be considered as an autonomous entity. The mechanism of the hyperpigmentation is not known.

Child↗
PubMed1986

Tumour of Wagner-Meissner touch corpuscles. Wagner-Meissner neurilemmoma.

Two benign tumours composed mainly or exclusively of Wagner-Meissner corpuscles are described. In the first case the touch corpuscles are composed of closely piled laminar cells and surrounded by argyrophilic fibres. In the second case some Schwann cells are observed in between the tactile corpuscles. The light microscopic, electron-microscopic and immunohistochemical results demonstrate that these corpuscles are comparable with the tactile end organs of the skin. Immunohistochemically, neuron-specific enolase, vimentin and protein S-100 could be demonstrated in the tactile corpuscles. Neural processes present in normal Meissner corpuscles are absent and immunohistochemically no nerve fibres or nerve endings can be demonstrated using antibodies to neurofilaments as they are observed in normal touch corpuscles of the skin. Tumours which consist mainly of multiple touch corpuscles have not been described in the literature. It is suggested to call these tumours Wagner-Meissner neurilemmoma.

Adult↗