Angiotropic lymphoma: An immunophenotypically and clinically heterogeneouslymphoma

Angiotropic lymphoma (AL) is an uncommon lymphoma often presenting with non specific clinical features and having a high mortality rate. Although not s pecifically recognized by the Revised European-American Classification of L ymphoid Neoplasms, it likely will appear as a subtype of diffuse large B-ce ll lymphoma in the upcoming WHO classification. Some authors may also consi der it to be a subtype of cutaneous lymphomas. Recent studies have reported an immunophenotypic heterogeneity of AL, and in rare instances, an associa tion with other NHL. To further characterize AL, we studied the immunopheno type by immunohistochemistry for CD5, CD10, CD20, bcl-2, and bcl-6 in 18 ca ses of B-cell AL identified at three medical centers in North America. Bcl- 2 gene rearrangement status by polymerase chain reaction and Epstein Barr v irus status by in situ hybridization also were evaluated. Eight men and 10 women were identified with AL (median age 71 years). Eleven patients were d iagnosed in life and seven were diagnosed at autopsy. Neurologic symptoms w ere the most common presentation, seen in six patients. Skin was the most c ommonly biopsied site. All showed classic intravascular localization; in tw o cases, there was also a minor diffuse large cell lymphoma component obser ved in some organs. Most (89%) of the cases expressed bcl-2 protein; CD10, bcl-6 and CD5 were each expressed in 22% of cases. Based on CD5 and CD10 ex pression, three major groups were evident: CD5-, CD10- (11 cases); CD5+, CD 10- (3 cases), and CD5-, CD10+ (3 cases). Even though a follicle center lym phoma preceded the AL in one patient, we did not detect bcl-2 gene rearrang ement in any of these cases. All cases were negative for Epstein Barr virus . Of the five treated with chemotherapy, two achieved a complete remission. Based on these findings, we conclude that ALs are clinically and immunophe notypically heterogeneous and may represent more than one pathogenetic enti ty. In some instances AL may be preceded by another lymphoproliferative dis order, raising the possibility that some cases of AL may represent a transf ormation from another type of lymphoma. Cutaneous manifestations of AL are common; however, it appears to be a systemic lymphoma. Although often fatal , patients with AL who are diagnosed early and treated with chemotherapy ma y achieve remission.