[1369] Clinicopathologic Features of Lymphomatoid Granulomatosis, a Single Institute Experience.

Joo Y Song, Kieron Dunleavy, Nicole Grant, Theresa Davies-Hill, Mark Raffeld, Wyndham H Wilson, Elaine S Jaffe, Stefania Pittaluga. NCI, Bethesda, MD

Background: Lymphomatoid granulomatosis (LYG) is a rare angiocentric and angiodestructive EBV-associated B-cell lymphoproliferative disorder. It is hypothesized that these patients have defective immune surveillance of EBV+ B-cells. Historical outcomes of patients treated with steroids and/or chemotherapy have been poor (median survivals of 14 months). In our institution LYG grade I/II is now treated with IFα, while grade III is treated with immunochemotherapy (EPOCH-R). LYG is both challenging diagnostically and therapeutically. We report our institution's experience with this rare disease.
Design: We reviewed biopsies of LYG collected at our institution from 1993-2010. Grading of these lesions was based on morphologic features and the number of EBV+ B-cells (grade I 0-5, grade II <50, grade III >50) evaluated by in situ hybridization (2008 WHO classification).
Results: 64 patients (M:F 2.1:1, median age 43 years) with 131 biopsies were diagnosed with LYG. 92/131 biopsies were further graded based on the WHO classification with 32/92 grade I (34.8%), 20/92 grade II (21.7%), and 40/92 grade III (43.5%). The most frequently biopsied site was the lung (75/92, 81.5%). Other involved biopsy sites included kidney (2/92), brain (1/92), adrenal (1/92), pleura (1/92), liver (1/92), eye (1/92), and nasal cavity (2/92). However, lesions involving skin (15) and subcutaneous tissue (5) had distinctive features, showing prominent granulomatous inflammation and lacking EBV+ cells. IGH PCR on 34 biopsies was positive for a clonal process in 1/10 grade I (10%), 3/8 grade II (37.5%), and 7/16 grade III (43.8%), reflecting the greater number of large atypical cells in high grade lesions. Interestingly, 2/20 biopsies also showed clonal rearrangement for TRG PCR (1 grade I and 1 grade III), which is attributed to T-cell response to EBV infected cells. 18 patients had more than one biopsy (range 2-5 biopsies) performed within a 6 month interval to evaluate response to therapy. 6/18 had the same grade (3 grade I, 3 grade III) and 12/18 had different grades (1 grade I/II; 4 grade I/III; 6 grade II/III; 1 grade III/DLBCL). Of these 18 patients, 10 had extrapulmonary lesions which had a higher grade when compared to the pulmonary lesion in all except one. Histologic progression requires a change in treatment.
Conclusions: LYG is a rare EBV-associated lymphoproliferative disorder for which grading is important for choice of therapy. However, cutaneous lesions have distinctive features. Rebiopsy is advised to determine evidence of histological progression.
Category: Hematopathology

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 176, Wednesday Morning

 

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