RESUMO
<p><b>OBJECTIVE</b>To examine 10 cases with primary cutaneous CD30-positive anaplastic large cell lymphoma (ALCL), analyze their clinical manifestations and pathological and immunohistochemical features, and improve early diagnosis of this disease.</p><p><b>METHODS</b>We studied the morphological characteristics of primary cutaneous CD30-positive ALCL using histopathological methods. Leukocyte common antigen (LCA), CD20, CD30, CD45RO, CD68, epithelial membrane antigen (EMA), cytokeratin (CK) and HMB45 antibodies were used to determine the expression of their respective antigens from routine paraffin samples of the patients.</p><p><b>RESULTS</b>Ten patients (7 men and 3 women, aged 31 to 84 years) complained of subcutaneous masses or papular eruptions over their lower trunks and extremities. Histopathologically, the lesions were composed of numerous large round or oval pleomorphic cells. The cytoplasm was usually abundant, amphophilic or basophilic, and finely vacuolated. Nuclei were commonly eccentrically localized and lobated or horseshoed in shape, and multinucleated giant cells and Reed-Sternberg-like cells were seen. Nucleoli were generally multiple and large. Of the 10 patients, tumor cells displayed positive antigen expression of CD30 in all cases, positive CD45RO in 6 cases, positive CD20 in only 1 case, but negative CD45RO and CD20 expressions in 3 cases. Two patients died at 7 weeks and 3.4 years of follow-up, respectively.</p><p><b>CONCLUSION</b>Our study highlights the importance of histopathologic features and positive CD30 staining for differentiation of this disease from other malignant skin tumors.</p>