Vascular endothelial growth factor expression in malignant melanoma: prognostic versus diagnostic usefulness.

Vascular endothelial growth factor (VEGF), an endothelial cell mitogen, plays a role in angiogenesis and progression in malignant melanoma. VEGF expression was examined in 62 biopsy specimens of melanocytic proliferations, including 45 malignant melanomas, 3 cellular blue nevi, 12 atypical compound nevi, and 2 Spitz nevi. The cases of malignant melanoma included 11 in situ melanomas, 18 Clark Level II, 9 Clark Level III, and 7 Clark Level IV tissue samples. All of the specimens were fixed in formalin and embedded in paraffin. Cytoplasmic immunoreactivity for VEGF was demonstrated in 19 (42%) of 45 melanoma samples, but there was no immunoreactivity for VEGF exhibited by any of the atypical compound melanocytic nevi, cellular blue nevi, or Spitz nevi (P < .009). Immunoreactivity for VEGF was found to be related to tumor thickness (as evidenced by Clark level [P < .03]) and to absence of regression (P < .04). Although VEGF is not a useful prognostic indicator for malignant melanoma, it may be useful as a discriminating factor between malignant melanoma and benign melanocytic lesions, and it may offer some insight into tumor growth.     

Keratosis lichenoides chronica

Keratosis lichenoides chronica (KLC) is a rare chronic disorder of keratinization, characterized by the progressive development of erythematosquamous plaques and violaceous lichenoid hyperkeratotic papules, nodules and ridges. These lesions are most commonly found in a symmetrical distribution on the trunk and extremities and display a unique linear and/or reticulate pattern. The etiology of KLC remains unknown and the eruptions tend to be refractory to treatment. We describe a case of keratosis lichenoides chronica that improved with systemic retinoids.     

Immunolabeling pattern of syndecan-1 expression may distinguish pagetoid Bowen's disease, extramammary Paget's disease, and pagetoid malignant melanoma in situ

The differential diagnosis of pagetoid cells within the epidermis rests primarily between pagetoid Bowen's disease (PBD), extramammary Paget's disease (EPD), and pagetoid malignant melanoma (MIS) in situ. Although morphologic clues are often helpful in differentiating these lesions, the use of immunohistochemistry is often necessary to arrive at the correct diagnosis. Syndecan-1 is a cell-surface proteoglycan that mediates adhesion between cells and the extracellular matrix, and between cells themselves. Twenty-two cases of PBD, four cases of intraepidermal EPD, and 13 cases of MIS were examined for syndecan-1 immunoreactivity. Cell-membrane syndecan-1 immunoreactivity was evident in PBD, cytoplasmic syndecan-1 immunoreactivity was evident in EPD, whereas immunoreactivity for syndecan-1 was not present in MIS. The patterns of syndecan-1 immunoreactivity in these lesions may be a useful adjunct in the differentiation of PBD, EPD, and MIS.     

Modulation of the effect of l-ß-D-Arabinofuranosylcytosine based on changes of Cytidine Deaminase activity in Hl60 Cells

The effect of changes in cytidine deaminase activity on the growth inhibitory effect of 1-ß-D-arabinofuranosylcytosine (Ara-C) has been investigated in the human promyelocytic cell line, HL60. 1,25 Dihydroxy vitamin D₃ (vit. D₃), which is an inducer of differentiation, caused an increase of cytidine deaminase in HL60 cells simultaneous with an inhibition of the effect of Ara-C. On the other hand, retinoic acid, which also induces differentiation had no influence on either the activity of cytidine deaminase or the effect of Ara-C. An atoxic inhibitor of cytidine deaminase tetrahydrouridine, THU, enhanced the effect of Ara-C. THU also enhanced the effect of Ara-C, even if the Ara-C effect was inhibited by deoxycytidine. These results show that it is possible to modulate the effect of Ara-C by changing the activity of cytidine deaminase. Furthermore, changes in the activity of cytidine deaminase and the effect on the Ara-C growth inhibition vary dependent on the differentiating inducer used.