[1291] Nodular Lymphocyte Predominant Hodgkin Lymphoma: Atypical Morphologic Features Correlate with Clinically Aggressive Disease

JT Bunning, U Popat, LJ Medeiros. MD Anderson Cancer Center, Houston, TX

Background: Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a clinically indolent Hodgkin lymphoma, but some patients develop clinically aggressive disease. The goal of this study was to characterize the histologic and immunohistochemical features of NLPHL in patients with clinically aggressive disease.
Design: 19 patients formed the study group. Each patient had biopsy-proven NLPHL and subsequently developed aggressive disease manifested by: transformation to large B-cell lymphoma, bone marrow involvement, or multiple relapses that became unresponsive to standard therapy. All patients eventually underwent stem cell transplantation. In each patient, biopsy showed typical morphologic features of NLPHL, at least partially, and LP cells were CD20+. Features specifically evaluated included: architectural pattern, LP cell morphology, tumor cell immunophenotype, degree of small B-cell depletion, and presence of necrosis and/or fibrosis. For comparison, we randomly selected patients with NLPHL who had an indolent clinical course.
Results: The study group (n=19) consisted of 16 men and 3 women (median age, 28 yrs; range: 4 to 56) with mean follow-up of 8.6 yrs. (range: 4 mos. to 21 yrs). Extensive (>50%) diffuse areas were present in the biopsies of 11/19 (58%) patients, and 16 (84%) patients had minor (>10-20%) diffuse areas. Dense fibrosis/sclerosis was noted in 14/19 (74%) biopsy specimens and varied from focal (<10%) in 6 patients to 10-40% in 7 patients. Abnormal tumor cell morphology was noted in 18/19 (95%) cases, with > 50% neoplastic cells deviating from classic LP cytologic features in 11 cases (58%). Increased extranodular large cells were noted in 17/19 (89%) cases. Weak or focal expression of CD30 (n = 4) or CD15 (n = 4) by the LP cells was present in 8/19 (42%) cases. Depletion of small B-cells in greater than 50% of the nodular areas was noted in 15/19 (79%) cases. When compared with the patients with indolent NLPHL, features significantly more common in the study group included diffuse pattern (P = 0.0003), B-cell depleted nodules (P = 0.007), atypical cytology of LP cells (P = 0.008), increased extranodular large cells (P = 0.03), and fibrosis (P = 0.04). Necrosis and immunophenotypic aberrancies were not significantly different.
Conclusions: Patients with clinically aggressive NLPHL have biopsy specimens that frequently demonstrate atypical histologic features: extensive diffuse pattern, atypical LP cells, increased extranodular LP cells, and depletion of B-cells.
Category: Hematopathology

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 207, Wednesday Morning

 

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