Subcutaneous metastasis of peritoneal mesothelioma diagnosed by fine-needle aspiration.

Mesothelioma is a rare malignant neoplasm of the serosal membranes, which can give distant metastases in various organs in advanced stages of its course. Subcutaneous tissue is an unusual metastatic site. In the literature, only one case of metastatic mesothelioma to the skin of the face has been reported. We present a case of a 60-year-old female with a prior history of peritoneal malignant mesothelioma, who 6 months after the initial diagnosis presented with a subcutaneous nodule in the lateral chest wall. Cytological examination of the material obtained by FNA from the nodule revealed metastatic mesothelioma. Although subcutaneous metastasis of malignant mesothelioma is a rare entity, one must always keep this possibility in mind and proceed to further investigation of such lesions. In these cases, FNA is a simple diagnostic procedure for the identification of metastatic disease in patients with a prior history of malignancy.

Immunohistochemical HLA-DR antigen expression with lymphocyte subsets and proliferative activity in pterygium.

The immunohistochemical expression of HLA-DR antigen, CD8, CD4, CD68, S1OO, PCNA and Ki-67 was performed in order to investigate the role of immune mechanisms in pterygium, in correlation with proliferative activity. A series of 98 surgically-excised pterygia, 18 pingueculae and 20 normal conjunctivae, was studied by the avidin-biotin method, on formalin-fixed, paraffin-embedded tissue. HLA-DR antigen was abundantly expressed in pterygium epithelial cells, whereas almost no expression was found in pinguecula and normal conjunctiva. A high value of Ki-67 and PCNA expression coexisted in the same areas with HLA-DR antigen expression in pterygium and a statistically significant positive correlation resulted between them (p = 0.002). Aberrant infiltration of inflammatory cells (CD4, CD8, CD68, S100) was detected in pterygium, while lower densities were found in pinguecula and conjunctiva. The data suggest that immunopathological mechanisms may contribute in the pathogenesis of pterygium. In addition, the aberrant HLA-DR antigen expression seems to be correlated with the growth fraction of the lesion.