A clinicopathologic study of orbital and ocular adnexal lymphoproliferative lesions with immunohistochemical staining of indeterminate cases

The histopathologic diagnosis of orbital and ocular adnexal lymphoproliferative lesions is difficult, resulting controversy in classification, determining benignity or malignancy of them and treatment modality selection. We designed the following study to evaluate clinical, histopathologic and if necessary immunochemical features of them in decreasing indeterminate cases. The study includes 51 subjects of biopsy-proven orbital lymphoid lesions and inflammatory pseudotumors from pathologic practices of Farabi and Imain Khomeini Hospitals, from April 1994 to March 2000. We reviewed H&E stained slides. Then we examined clonality of indeterminate cases with evaluation of clonal immunoglobulin light chains (ĸ or λ) expression to find neoplastic cells. CD markers were used for excluding other closed morphologic differential diagnosis. In conclusion we determined 40 cases of lymphoproliferative lesions, divided to the following there groups: malignant lymphoma with sixty-five percent frequency were the most common type of them, reactive lymphoid hyperplasia with twenty percent was the second one and atypical lymphoid hyperplasia with fifteen percent was the third one. The most common site of involvement was orbit (57.5%). Males were affected slightly higher than females. Median age at diagnosis was 62 years. The most common type of lymphoma group was low-grade small lymphocytic lymphoma. It is necessary to note that 11 out of total 51 subjects were excluded under other pathologic diagnosis. On the other hand 4 cases of already diagnosed pseudo-tumors were reclassified into three lymphoid lesion categories above.