Immunostaining for CD31 and CD34 in Kaposi sarcoma.

Aims: To evaluate antibodies directed against CD31 (JC70/A) and CD34 (QBEND/10 and anti-HPCA-1) more extensively in Kaposi sarcoma; to assess their value in routine diagnosis; and to compare them with the traditional endothelial cell markers Ulex europaeus agglutinin 1 (UEA-1) and factor VIII related antigen.

Methods: Twenty four cases of Kaposi sarcoma were studied retrospectively. All specimens had been fixed in formalin and embedded in paraffin wax.

Solitary and generalized variants of spindle cell xanthogranuloma (progressive nodular histiocytosis).

Twelve cases of solitary spindle cell xanthogranuloma, seven of which had originally been misdiagnosed as dermatofibroma/benign fibrous histiocytoma, were clinicopathologically compared with four cases of progressive nodular histiocytosis, a rare generalized non-X histiocytic disorder. Clinically, a single brown-yellowish papule or nodule is characteristic of solitary spindle cell xanthogranuloma, multiple generalized lesions of progressive nodular histiocytosis. Solitary spindle cell xanthogranuloma occurs with decreasing frequency on the head, neck, upper trunk, or occasionally the extremities of young adults (aged 20-40 years), progressive nodular histiocytosis mostly on the trunk of older patients (aged 40-60 years), both without sex predilection.

Immunocytochemistry in the diagnosis of Kaposi's sarcoma and angiosarcoma.

Immunocytochemistry in the assessment of Kaposi's sarcoma and angiosarcoma is reviewed, with emphasis on the technical appraisal of the appropriate panel of markers. Problems incurred in the interpretation of the pathological spectrum of both tumours are discussed.

Reticulohistiocytoma and multicentric reticulohistiocytosis. Histopathologic and immunophenotypic distinct entities.

The clinicopathological and immunohistochemical features of four patients with systemic multicentric reticulohistiocytosis (MR) were compared with five cases of solitary and one case of multiple reticulohistiocytoma (RH), which were confined to the skin only. The MR cases mostly affected the limbs of older women, while RH affected young male adults without preference to site. Characteristically, both entities consisted of oncocytic mononuclear histiocytes (with granular eosinophilic cytoplasm similar to oncocytic thyroid cells) and multinucleated histiocytes with a ground-glass appearance, which appeared to be much larger (> 200 microns) and bizarre in cases of RH compared with cases of MR (50-100 microns).

Cutaneous crystalline deposits in myeloma.

Background: Myeloma is a plasma cell malignancy that usually presents with systemic manifestations or symptoms related to bone involvement. We describe the first case of crystalline protein deposition in the skin as the initial manifestation of myeloma.

Observations: Crystals were found mainly in the extracellular space in the dermis of both involved and uninvolved skin in the absence of plasma cell infiltration.