• ALK-negative ALCLs have chromosomal rearrangements of DUSP22 or TP63 in 30% and 8% of cases, respectively. • DUSP22-rearranged cases have favorable outcomes similar to ALK-positive ALCLs, whereas other genetic subtypes have inferior outcomes.Anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL) is a CD30-positive T-cell non-Hodgkin lymphoma that morphologically resembles ALKpositive ALCL but lacks chromosomal rearrangements of the ALK gene. The genetic and clinical heterogeneity of ALK-negative ALCL has not been delineated. We performed immunohistochemistry and fluorescence in situ hybridization on 73 ALK-negative ALCLs and 32 ALK-positive ALCLs and evaluated the associations among pathology, genetics, and clinical outcome. Chromosomal rearrangements of DUSP22 and TP63 were identified in 30% and 8% of ALK-negative ALCLs, respectively. These rearrangements were mutually exclusive and were absent in ALK-positive ALCLs. Five-year overall survival rates were 85% for ALK-positive ALCLs, 90% for DUSP22-rearranged ALCLs, 17% for TP63-rearranged ALCLs, and 42% for cases lacking all 3 genetic markers (P < .0001).Hazard ratios for death in these 4 groups after adjusting for International Prognostic Index and age were 1.0 (reference group), 0.58, 8.63, and 4.16, respectively (P 5 7.10 3 10 25

Key Points DUSP22-rearranged ALCLs belong to a distinct subset of ALCLs lacking activated STAT3. DUSP22-rearranged ALCLs have a unique molecular signature characterized by DNA hypomethylation and an immunogenic phenotype.

Lymphomatoid granulomatosis (LYG) is a rare angiocentric and angiodestructive EBV-associated B-cell lymphoproliferative disorder. It is hypothesized that these patients have dysregulated immune surveillance of EBV. We reviewed the biopsies of 55 patients with LYG who were referred for a prospective trial at the NCI (1995–2010) and evaluated the histologic, immunohistochemical, in situ hybridization, and molecular findings of these biopsies in conjunction with clinical information. Grading of the lesions was based on morphologic features and the number of EBV-positive B cells. The median age was 46 years (M:F 2.2:1). Clinically, all patients had lung involvement (100%) with the next most common site being the central nervous system (38%). No patient had nodal or bone marrow disease. All patients had past EBV exposure by serology but with a low median EBV viral load. We reviewed 122 biopsies; the most common site was lung (73%) followed by skin/subcutaneous tissue (17%); other sites included kidney, nasal cavity, gastrointestinal tract, conjunctiva, liver, and adrenal gland. Histologically the lesions showed angiocentricity, were rich in T cells, had large atypical B cells, and were positive for EBV. Grading was performed predominantly on the lung biopsy at diagnosis; they were distributed as follows: LYG grade 1 (30%), grade 2 (22%), and grade 3 (48%). Necrosis was seen in all grades with a greater degree in high-grade lesions. Immunoglobulin gene rearrangement studies were performed and a higher percentage of clonal rearrangements were seen in LYG grade 2 (50%) and grade 3 (69%) as compared to grade 1 (8%). LYG is a distinct entity that can usually be differentiated from other EBV-associated B-cell lymphoproliferative disorders based on the combination of clinical presentation, histology, and EBV studies. Grading of these lesions is important because it dictates the treatment choice.