Long-Lived Plasma Cells Are Contained within the CD19(-)CD38(hi)CD138(+) Subset in Human Bone Marrow.

Antibody responses to viral infections are sustained for decades by long-lived plasma cells (LLPCs). However, LLPCs have yet to be characterized in humans. Here we used CD19, CD38, and CD138 to identify four PC subsets in human bone marrow (BM). We found that the CD19(-)CD38(hi)CD138(+) subset was morphologically distinct, differentially expressed PC-associated genes, and exclusively contained PCs specific for viral antigens to which the subjects had not been exposed for more than 40 years. Protein sequences of measles- and mumps-specific circulating antibodies were encoded for by CD19(-)CD38(hi)CD138(+) PCs in the BM. Finally, we found that CD19(-)CD38(hi)CD138(+) PCs had a distinct RNA transcriptome signature and human immunoglobulin heavy chain (VH) repertoire that was relatively uncoupled from other BM PC subsets and probably represents the B cell response's "historical record" of antigenic exposure. Thus, our studies define human LLPCs and provide a mechanism for the life-long maintenance of anti-viral antibodies in the serum.

Human herpesvirus 8-related diseases: Histopathologic diagnosis and disease mechanisms.

The emergence of HIV/AIDS more than three decades ago led to an increased incidence of diseases caused by HHV8 co-infection, particularly Kaposi sarcoma, primary effusion lymphoma, and multicentric Castleman disease. Over time, the development of highly effective AIDS therapies has resulted in a decreased incidence of HHV8-associated entities, which are now more commonly found in patients with undiagnosed and/or untreated AIDS. Due to their rarity, some of these diseases may be difficult to recognize without appropriate clinical information. This article provides an overview of HHV8-related disorders, with a focus on their morphologic and phenotypic features, and includes a brief overview of laboratory methods used to detect HHV8. Disease mechanisms by which the HHV8 virion promotes tumorigenesis are also reviewed.

Significant Variability in the Identification and Reporting of Band Neutrophils by Participants Enrolled in the College of American Pathologists Proficiency Testing Program: Time for a Change.

CONTEXT.­: Increased band neutrophils in blood smear differential counts ("bandemia") are entrenched in medicine as a flag for sepsis. However, laboratory hematology experts have long advocated for discontinuation of reporting bands separately from segmented neutrophils because of poor sensitivity and specificity, poor interobserver agreement, and availability of alternative biomarkers for sepsis. OBJECTIVE.­: To describe band neutrophil reporting practices and reproducibility of band classification among laboratories participating in the College of American Pathologists (CAP) proficiency testing (PT) program. DESIGN.­: A survey questionnaire was distributed to hematology PT participants. A subsequent morphologic challenge included 12 preselected cell identifications of segmented neutrophils, bands, and metamyelocytes, and a 100-cell manual differential count of a digitally scanned blood smear. RESULTS.­: Among laboratories that reported manual differentials, most respondents reported bands (4554 of 5268; 86.4%). Only 3222 of 4412 respondents (73.0%) provided band reference ranges. Though participants classified "easy" band neutrophils well (78.0%-98.3%), categorization of cell identifications for "moderate" and "difficult" bands was poor (3.1%-39.0% of laboratories), with classification instead as segmented neutrophils. This pattern was seen regardless of laboratory demographic characteristics. Marked variability in band counts was observed on the 100-cell differential count for both CAP PT participants and CAP Hematology and Clinical Microscopy Committee (HCMC) members (coefficients of variation, 55.8% and 32.9%, respectively). Variability was significantly improved when segmented and band neutrophils were grouped together (coefficients of variation, 6.2% and 5.0%, respectively). CONCLUSIONS.­: Most CAP PT-participating laboratories report band counts, many without reference ranges. The survey confirms significant interlaboratory variability of band enumeration when bands are separately identified from segmented neutrophils. This study reaffirms the CAP Hematology and Clinical Microscopy Committee's strong recommendation to group segmented and band neutrophils together in manual differential counts.

Poorly Cohesive (Signet Ring Cell) Carcinoma of the Ampulla of Vater.

In the ampulla of Vater, carcinomas with "diffuse-infiltrative"/"signet ring cell" morphology, designated as "poorly cohesive carcinoma" (PCC) in the WHO classification, are very rare and poorly characterized. Nine cases with a classical PCC morphology constituting >50% of the tumor were identified. Mean age was 64.8 years (vs 64.6 in ampullary carcinomas [ACs]) and 6 were males, 3 females. The mean invasive tumor size was 2.5 cm (vs 1.9 in ACs). Other morphologic patterns displayed included cord-like infiltration (n=2), plasmacytoid cells (n=2), and microglandular component (n=4), including goblet cell adenocarcinoma-like foci. None of the cases were associated with dysplasia. By immunohistochemistry, the carcinomas did not show intestinal differentiation (CDX2 0/9, CK20 1/9, MUC2 3/9), MUC1 was positive in 4/9, MUC5AC was positive in 7/8. E-cadherin loss was noted in 4/9. All cases were advanced stage (6/9-pT3, 3/9-pT4) (vs 43% in ACs). Lymph node metastases were identified in 44% (vs 45% in AC). Six patients (67%) died of disease at a median of 25 months, 3 were alive at 13, 15, and 60 months. Overall median survival was significantly worse than that of intestinal-type ACs (26 vs 122 months, P = .006) and trended toward worse than pancreatobiliary type (26 vs 42 months, P = .1). In conclusion, PCCs constitute 2.45% of all ACs. These present as advanced tumors and express upper-gastrointestinal immunoprofile with frequent MUC5AC labeling, which may be helpful in identifying subtle infiltration in the surface mucosa since MUC5AC is not expressed in the ampullary mucosa. Patients have poor prognosis.

Multimodality Technologies in the Assessment of Hematolymphoid Neoplasms.

Accurate assessment of tissues for hematolymphoid neoplasms requires an integrated multiparameter approach. Although morphologic examination by light microscopy remains the mainstay of initial assessment for hematolymphoid neoplasms, immunophenotypic analysis by immunohistochemistry and/or flow cytometry is essential to determine the pattern of differentiation and to detect minimal disease when morphology is inconclusive. In some cases, immunophenotypic analysis provides additional information for targeted immunotherapy and prognostication. Genotypic studies, including cytogenetics, fluorescence in situ hybridization, DNA microarray, polymerase chain reaction, and/or next-generation sequencing, are also imperative for subclassification of the genetically defined disease entities in the current World Health Organization classification of hematolymphoid neoplasms. Moreover, genotypic studies can establish clonality, stratify patients to determine appropriate treatment, and monitor patients for treatment response.

Successful Robotic Excision and Early Chemotherapy for Primary Cardiac Lymphoma.

We present a 67-year-old patient who underwent robotic excision of a mobile left ventricular mass found incidentally on echocardiography. Intraoperative findings revealed a pedunculated mass infiltrating the interventricular septum, and the results of pathologic examination of the frozen section were consistent with malignancy. The final pathologic examination showed a diffuse large B-cell lymphoma, and early chemotherapy was initiated. Follow-up cardiac positron emission tomography/computed tomography showed completely normal myocardium without evidence of malignancy. The lateral endoscopic robotic approach across the mitral valve permitted optimal tumor visualization and early chemotherapy initiation without concern for cardiac rupture or related adverse events.

CD30+ Cutaneous T Cell Lymphoma: Response to Rotational Total Skin Electron Irradiation.

INTRODUCTION: Rotational total skin electron irradiation (RTSEI) is an effective therapy for cutaneous T cell lymphoma (CTCL). CD30 expression has been identified as a prognostic factor in CTCL. Therefore, we investigated CD30 status, treatment response, and survival in our cohort of patients with CTCL treated with RTSEI. METHODS: Patients with CTCL treated with RTSEI (≥30 Gy) between 2000 and 2013 at our institution were identified, and clinical and pathologic data were retrospectively reviewed. Primary outcomes were complete clinical response (CCR; >90% reduction of skin disease burden), relapse-free survival (RFS), and overall survival (OS). RESULTS: Sixty-eight patients with CTCL treated with RTSEI were identified. Median age at diagnosis was 51 years with median follow-up of 61 months. Median OS was 76 months and median RFS was 11 months. Thirteen patients (19%) had CD30+ lymphocytes on initial pathology. In the CD30+ cohort, there were no T2, eight T3, and five T4 cases. In comparison, in the CD30- cohort, there were 18 T2, 29 T3, and 8 T4 cases (P = 0.01). Six weeks post-RTSEI, CCR was 85% in CD30+ and 81% in CD30- cases (P = 1). Six months post-RTSEI, CCR was 23% in CD30+ and 50% in CD30- cases (P = 0.083). CONCLUSION: RTSEI resulted in excellent CCR at 6 weeks in our cohort of patients with CTCL, with a median RFS of 11 months. We found CD30+ patients presented with significantly higher T stage at time of RTSEI and trended towards decreased CCR at 6 months post-RTSEI compared with the CD30- group.

Immunohistochemical detection of p16INK4a in dysplastic lesions of the oral cavity.

Significant intra- and interobserver variability exists in diagnosing and grading oral epithelial dysplasia. Mutations in the tumor-suppressor gene p16 are common in oral cavity dysplastic lesions, but whether immunohistochemical detection of the gene product p16(INK4a) (p16) can be used as a reliable biomarker for dysplasia is unclear. In total, 119 biopsy specimens representing various oral cavity sites and degrees of dysplasia were retrieved from the pathology files of Emory University Hospital. Formalin-fixed, paraffin-embedded sections were stained with hematoxylin and eosin (H&E) and with a monoclonal antibody to p16 (LabVision Corporation, Clone JC2). A blinded review of the H&E slides and the pattern and degree of p16 expression was independently performed by two pathologists. A consensus was obtained when diagnoses differed. Morphologic diagnoses were then compared to p16 immunohistochemical expression. Overall, 61/119 (51%) cases showed no p16 immunoreactivity, including 12/33 (36%) cases of no dysplasia, 11/28 (39%) cases of mild dysplasia, and 38/58 (66%) cases of moderate/severe dysplasia. The remaining cases showed p16 expression limited to the basal and suprabasal nuclei and generally confined to the lower one-third of the epithelium. A logistic regression model showed a trend toward absent p16 expression with increasing severity of dysplasia (P=0.006). Decreased expression of p16 in dysplastic lesions, as found in this study, may reflect the biologic events involving loss of p16 gene function in the pathogenesis of oral cancer. Our findings suggest that p16 immunohistochemistry is not helpful in differentiating dysplastic from nondysplastic mucosa in oral cavity biopsies, and thus is not a reliable biomarker for use in routine clinical practice.