Transformation of Follicular Lymphoma to Acute Lymphoblastic Leukemia Xiaoping Sun, MD, PhD; Leo I. Gordon, MD; LoAnn C. Peterson, MD n March 1994, a 56-year-old man underwent lobectomy sies showed a single paratrabecular lymphoid aggregate I of the upper lobe of the right lung and lymph node that suggested involvement by the follicular lymphoma. dissection for poorly differentiated adenocarcinoma. Ma- During the next 6 years, the patient underwent 2 biopsies lignant lymphoma, follicular, small cleaved was identi®ed and 2 ®ne-needle aspiration biopsies of lymph nodes from in multiple paratracheal and hilar lymph nodes. Hema- different sites, and the results of all of these biopsies were toxylin-eosin±stained sections of the lymph nodes showed consistent with the initial diagnosis. Flow cytometric im- a follicular pattern and a predominance of small cleaved munophenotyping was performed on 3 of the lymph node lymphoma cells (Figure, A). Bilateral bone marrow biop- specimens, and all contained CD101 and CD52 clonal B cells (CD191 and CD201) with l surface immunoglobulin light chain restriction. In August of 1999, 5 years after the Accepted for publication March 1, 2002. initial diagnosis, repeated bilateral bone marrow biopsies From the Department of Pathology, Northwestern University Medical School, Chicago, Ill. showed a normocellular bone marrow with 2 nonparatra- Reprints: LoAnn C. Peterson, MD, Department of Pathology, North- becular lymphoid aggregates; these ®ndings were not di- western University Medical School, Feinberg Pavilion, Room 7-344, agnostic for lymphoma. Flow cytometry studies of the 251 East Huron St, Chicago, IL 60611 (e-mail:
[email protected]). bone marrow showed no evidence of B-cell clonality.