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Fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL) is a provisional entity in the 2017 Revision of the World Health Organization Classification. This indolent entity, which is frequently discovered incidentally, is currently classified under the category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI), an aggressive lymphoma with poor survival. Several authors have proposed that it be classified separately since, in contrast to DLBCL-CI, transformation to aggressive lymphoma has rarely been reported and this entity has distinct clinical and histological features. We describe a rare case of a 62-year-old male with FA-DLBCL associated with atrial myxoma, which was incidentally discovered. In contrast to typically described immunophenotypic features of this entity, that is, activated B-cell phenotype (ABC) and Epstein-Barr virus (EBV) positivity, our case showed germinal center B-cell (GCB) phenotype and was EBV negative. Clinical staging revealed no evidence of lymphoma elsewhere in the body, and the patient did not receive adjuvant chemotherapy after surgical excision and remains in remission. This case illustrates that occasionally FA-DLBCL can show GCB phenotype, as opposed to the typical ABC phenotype. Moreover, we propose that the definition of the entity be expanded to include EBV-negative cases. [ABSTRACT FROM AUTHOR]

The article discusses historical foundations underlying anti-SLAPP statutes, as well as the foggy saga of the Erie progeny. It mentions anti-SLAPP statute, triggering a nationwide movement towards protecting plaintiffs against meritless defamation countersuits. It also mentions Second Circuit Court of Appeals vacated the district court's ruling since it conflicted with the Federal Rules of Civil Procedure and state laws under the Rules Enabling Act of 1934.

* Langerhans cell histiocytosis (LCH) comprises a wide spectrum of clinical disorders that have in common a proliferation of Langerhans-type cells with characteristic morphologic, immunophenotypic, and ultrastructural features. In part because of the diverse clinical manifestations of LCH, there has long been controversy over whether LCH is best considered a reactive process or a neoplasm. Herein, we discuss the clinical and pathologic features of LCH, including recent advances in the understanding of the molecular pathogenesis of this disease that support its categorization as a neoplasm. We also review the implications that these recently described molecular characteristics may have on risk stratification and treatment of LCH. (Arch Pathol Lab Med. 2015; 139:1211-1214; doi: 10.5858/arpa.2015-0199-RA), Langerhans cell histiocytosis (LCH) is a rare disease marked by proliferation of Langerhans-type cells that share immunophenotypic and ultrastructural similarities with antigen-presenting Langerhans cells of mucosal sites and skin. (1) [...]

Follicle center lymphomas, including primary cutaneous follicle center lymphoma (PCFCL), may rarely show plasmacytic differentiation. Such cases can pose a diagnostic challenge and can be mistaken for other lymphomas that more commonly include plasma cells. Here, we report four cases of PCFCL and one case of systemic follicular lymphoma involving the skin with associated monotypic plasma cells, including the clinical, morphologic and immunophenotypic features. [ABSTRACT FROM AUTHOR]

Context.--Primary cutaneous [CD4.sup.+] small/medium T-cell lymphoma is a provisional and controversial entity with a broad differential diagnosis. Despite being an uncommon lymphoma, it is a frequent diagnostic consideration in cutaneous biopsies with a dense lymphoid infiltrate because it shows overlapping features with reactive lymphoid hyperplasia (pseudolymphoma) and a variety of other primary cutaneous and systemic lymphomas. However, proper classification of this process is important for determining patient prognosis and treatment options. Objectives.--To review the clinical, morphologic, immunophenotypic, and genetic features of primary cutaneous [CD4.sup.+] small/medium T-cell lymphoma and contrast those features with entities in the differential diagnosis. Data Sources.--Applicable literature will be reviewed with emphasis on current controversies and distinguishing characteristics. Conclusions.--Although many consider primary cutaneous [CD4.sup.+] small/medium T-cell lymphoma to be indistinguishable from reactive lymphoid hyperplasia/ pseudolymphoma, it can be differentiated from other primary cutaneous and systemic lymphomas. Patients with solitary lesions of primary cutaneous [CD4.sup.+] small/medium T-cell lymphoma generally have an excellent prognosis. Nevertheless, a subset of patients who have been reported to meet criteria for this lymphoma have followed a more-aggressive course; however, those patients show some differing clinical, morphologic, and immunophenotypic features. (Arch Pathol Lab Med. 2014; 138:1307-1318; doi: 10.5858/arpa.2014-0299-CC), The concept of primary cutaneous [CD4.sup.+] small/medium T-cell lymphoma (PC-SMTCL) began in the early 1990s when the updated Kiel classification system (1,2) was applied to primary cutaneous T-cell lymphomas that [...]

Safe maximal surgical resection is the initial treatment of choice for pediatric brainstem low-grade gliomas. Optimal therapy for incompletely resected tumors or that progress after surgery is uncertain. We reviewed the clinical characteristics, therapy, and outcomes of all children with nontectal brainstem low-grade gliomas treated at the University of Michigan between 1993 and 2013. Median age at diagnosis was 6 years; histology was confirmed in 23 of 25 tumors, 64% were pilocytic astrocytoma. Nineteen patients underwent initial tumor resection; 14/19 received no upfront adjuvant therapy. Eight patients in the study had progressive disease; 5 initially resected tumors received chemotherapy at tumor relapse, all with partial or complete radiographic responses. Ten-year progression-free survival is 71% and overall survival, 100%. This single-institution retrospective study demonstrates excellent survival rates for children with brainstem low-grade gliomas. The efficacy of the well-tolerated chemotherapy in this series supports its role in the treatment of unresectable or progressive brainstem low-grade gliomas. [ABSTRACT FROM AUTHOR]

Oncocytic sinonasal papillomas (OSPs) are benign tumours of the sinonasal tract, a subset of which are associated with synchronous or metachronous sinonasal squamous cell carcinoma (SNSCC). Activating EGFR mutations were recently identified in nearly 90% of inverted sinonasal papillomas (ISPs) - a related tumour with distinct morphology. EGFR mutations were, however, not found in OSP, suggesting that different molecular alterations drive the oncogenesis of these tumours. In this study, tissue from 51 cases of OSP and five cases of OSP-associated SNSCC was obtained retrospectively from six institutions. Tissue was also obtained from 50 cases of ISP, 22 cases of ISP-associated SNSCC, ten cases of exophytic sinonasal papilloma (ESP), and 19 cases of SNSCC with no known papilloma association. Using targeted next-generation and conventional Sanger sequencing, we identified KRAS mutations in 51/51 (100%) OSPs and 5/5 (100%) OSP-associated SNSCCs. The somatic nature of KRAS mutations was confirmed in a subset of cases with matched germline DNA, and four matched pairs of OSP and concurrent associated SNSCC had concordant KRAS genotypes. In contrast, KRAS mutations were present in only one (5%) SNSCC with no known papilloma association and none of the ISPs, ISP-associated SNSCCs, or ESPs. This is the first report of somatic KRAS mutations in OSP and OSP-associated SNSCC. The presence of identical mutations in OSP and concurrent associated SNSCC supports the putative role of OSP as a precursor to SNSCC, and the high frequency and specificity of KRAS mutations suggest that OSP and OSP-associated SNSCC are biologically distinct from other similar sinonasal tumours. The identification of KRAS mutations in all studied OSP cases represents an important development in our understanding of the pathogenesis of this disease and may have implications for diagnosis and therapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]