Lymphoid tumors of the orbit and ocular adnexa: a clinicopathologic study of 42 cases.

Clinicopathologic features of lymphoid tumors of the orbit and ocular adnexa were documented in 42 cases treated at the Kyushu University Hospital during the period from 1965 through 1980. There were 30 cases with malignant lymphoma and 12 cases with reactive lymphoid lesions. According to the new histological classification proposed by the Japanese Lymphoma Study Group for non-Hodgkin's malignant lymphoma, the malignant lymphoma group included 22 cases of small cell type, 3 cases of medium-sized cell type and 5 cases of large cell type. The small cell type tumors were further divided into two groups, those with and without monoclonal intracytoplasmic immunoglobulin (IgM or IgA). The former was usually located in the subconjunctival tissue and its local recurrence after extirpation was rare. A few cases showed intranuclear inclusions (Dutcher bodies). By electron microscopy, the cells were found to exhibit plasmocytoid differentiation: laminated rough endoplasmic reticulum was well developed and condensed heterochromatin was seen at the margin of the round nuclei. The latter group of small cell tumors was situated mainly in the anterior portion of the orbit and occasionally recurred after surgical removal and steroid therapy. These tumor cells showed no plasmocytoid differentiation, when studied by electron microscopy. The medium-size and large cell types presented clinicopathologic features similar to nodal lymphoma. In the reactive lymphoid lesions, polyclonal intracytoplasmic immunoglobulins were identified in the proliferating lymphoid cells.