Hepatosplenic T cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy number alterations in the disease. Chromatin modifying genes including SETD2, INO80 and ARID1B were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%) for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS and TP53. SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates novel gene mutations linked to HSTL pathogenesis and potential treatment targets.

Extranodal marginal zone lymphomas (EMZL) are the most common lymphomas in the ocular adnexa. The etiology and potential role for antigenic stimulation in these lymphomas are still controversial. We have examined IGHV gene usage and mutations in 67 Chlamydophila psittaci-negative ocular adnexal EMZL. Clonal IGHV gene sequences were identified in 43 tumors originating from the orbit (19), conjunctivae (18) and lacrimal gland (6). Forty four potentially functional clonal IGHV gene sequences were detected with overrepresentation of the IGHV4 family and IGHV4-34 gene. All but 3 sequences were mutated with the average percent homology to the germ line of 93.5±6.1. Multinomial model and Focused binomial test demonstrated evidence for positive and/or negative antigen selection in 59% of the potentially functional IGHV genes. Intraclonal variation was detected in 8 of 11 tumor specimens. Overall our findings demonstrate that C. psittaci-negative ocular adnexal EMZL exhibit biased usage of IGHV families and genes with evidence for intraclonal heterogeneity and antigen selection in multiple tumors, implicating B-cell receptor-mediated antigen stimulation in the pathogenesis of these lymphomas.

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The etiology and pathogenesis of ocular adnexal extranodal marginal zone lymphoma (OAEMZL) are still unknown and the association with Chlamydophila psittaci (C. psittaci) has been shown in only some geographic regions. Herein we comprehensively examined the frequency of chromosomal translocations as well as CARD11, MYD88 (L265P) and A20 mutations /deletions in 45 C. psittaci negative OAEMZLs. t(14;18)(q32;q21) IGH-MALT1 and t(11;18)(q21;q21) API2-MALT1 were not detected in any of the analyzed tumors while 3 tumors harbored IGH translocations to an unidentified partner. CARD11 mutations were not found in all the analyzed tumors while MYD88 L265P mutation was detected in 3 (6.7%) tumors. A20 mutations and deletions were each detected in 7(15.6%) and 6(13.3%) of the tumors, respectively. Therefore, the observed genetic aberrations could account for the activation of NF-kB signaling pathway in only a minority of the cases. Further studies are needed to identify the molecular mechanisms underlying the pathogenesis of OAEMZL.

Previous studies have suggested that CD30 may be expressed in diffuse large B-cell lymphomas (DLBCLs). However, the prevalence of CD30 + DLBCLs and extent of CD30 expression within an individual tumor have not been fully evaluated. The aim of this study was to determine the frequency and extent of CD30 expression in DLBCLs, and explore possible relationships between CD30 expression and clinical and biologic variables. We retrospectively identified and analyzed 167 cases of CD30 + DLBCLs from our pathology archive. Twenty-one percent (95% confidence interval [CI]: 14.8-27.1%) of these cases expressed CD30, and in 52% of them CD30 was positive in > 80% of tumor cells. CD30 expression was more frequent in DLBCLs with non-germinal center origin phenotype, BCL2 + DLBCLs and in patients ≤ 47 years old. There was significant interaction of BCL2 expression with age and subtype of DLBCL. A multivariate analysis performed in BCL2 + DLBCLs showed a higher frequency of CD30 + cases in non-germinal center DLBCLs (odds ratio [OR]: 6.5, 95% CI: 1.1-36.5) and in patients ≤ 47 years old (OR: 6.9, 95% CI: 1.5-29.5). These associations could suggest a common biologic pathogenesis. The effectiveness of anti-CD30 drugs in other lymphomas opens the possibility for their use in patients with CD30 + DLBCLs.

A limited immunohistochemical panel of CK, CK5/6, p63, and HLA-DR is useful in discriminating nasopharyngeal, basaloid squamous cell, and high-grade neuroendocrine carcinomas of the sinonasal cavity and nasopharynx.

The pathogenesis of Chlamydophila psittaci-negative ocular adnexal extranodal marginal zone lymphomas (OAEMZLs) is poorly understood. OAEMZLs are monoclonal tumors expressing a biased repertoire of mutated surface immunoglobulins. Antigenic activation of the B-cell receptor (BCR) may have a role in the pathogenesis of these lymphomas. We have analyzed the reactivity of recombinant OAEMZL immunoglobulins. OAEMZL antibodies reacted with self-human antigens, as demonstrated by enzyme-linked immunosorbent assays, HEp-2 immunofluorescence and human protein microarrays. All the analyzed recombinant antibodies (rAbs) exhibited polyreactivity by comprehensive protein array antibody reactivity and some rAbs also demonstrated rheumatoid factor activity. The identity of several reactive antigens was confirmed by microcapillary reverse-phase high-performance liquid chromatography nano-electrospray tandem mass spectrometry. The tested rAbs frequently reacted with shared intracellular and extracellular self-antigens (for example, galectin-3). Furthermore, these self-antigens induced BCR signaling in B cells expressing cognate surface immunoglobulins derived from OAEMZLs. These findings indicate that interactions between self-antigens and cognate OAEMZL tumor-derived BCRs are functional, inducing intracellular signaling. Overall, our findings suggest that self-antigen-induced BCR stimulation may be implicated in the pathogenesis of C. psittaci-negative OAEMZLs.

Context.-We reported previously that more than onethird (37%) of primary bladder squamous cell carcinomas (SCCs) demonstrate diffuse p16 immunoreactivity independent of gender. This observation made us question whether p16 overexpression in bladder carcinoma is due to human papillomavirus (HPV)-dependent mechanisms.Objective.-To determine whether the presence of highrisk HPV (HR-HPV) DNA could be detected in these tumor cells.Design.-Fourteen cases of primary bladder SCC, which were positive for p16 by immunohistochemistry, were probed for the detection of HR-HPV by in situ hybridization and the signal amplification Invader assay. Samples positive for detection of HR-HPV by Invader assay were amplified by using HR-HPV type-specific primers, and amplification products were DNA sequenced.Results.-Detection of HR-HPV by the in situ hybridization method was negative in all cases (0 of 14). However, in 3 of 14 cases (21.4%), the presence of HR-HPV DNA was detected with the Cervista HPV HR Invader assay, which was followed by identification of genotype. All positive cases were confirmed by using HR-HPV typespecific amplification followed by DNA sequencing. Identified HR-HPV genotypes included HPV 16 (2 cases) and HPV 35 (1 case).Conclusions.-High-risk HPV DNA is detectable in a subset of primary bladder SCCs. Based on the welldocumented carcinogenic potential of HR-HPV, there is a necessity for additional studies to investigate the role of HR-HPV in bladder carcinogenesis.(Arch Pathol Lab Med. 2013;137:1088-1093; doi: 10.5858/arpa.2012-0122-OA) B ladder cancer is the second most common malignancy of the genitourinary tract diagnosed in the United States 1 with approximately 70 000 newly diagnosed cases and 14 000 deaths from disease annually. To date, wellestablished risk factors for the development of bladder squamous cell carcinoma (SCC) include increasing age (peak incidence at 50-70 years), male sex (male to female ratio, 3:1), smoking, exposure to carcinogenic chemicals, and chronic bladder inflammation and/or repeated urinary infections, and molecular/genetic factors. Although the oncogenic role of human papillomavirus (HPV) has been well documented in many epithelial cancers, including most cervical carcinomas, anogenital cancers, and carcinomas of the head and neck, its role in bladder carcinogenesis has been controversial throughout the literature.In gynecologic malignancies, the presence of high-risk HPV (HR-HPV) is often associated with overexpression of p16 protein. Immunohistochemistry for p16 is therefore used to screen for the presence of HR-HPV in primary cervical carcinomas.2 In a recent study, 3 we reported that more than-one third (37%) of primary bladder SCCs demonstrated diffuse p16 immunoreactivity independent of gender or tumor differentiation. From this study, we concluded that in tumors involving the pelvic cavity, the presence of p16 immunoreactivity alone cannot be used to distinguish tumors from gynecologic or urothelial origin. Our observed p16 overexpression in a significant proportion of...