Broadening the Morphologic Spectrum of Bartonella henselae Lymphadenitis: Analysis of 100 Molecularly Characterized Cases.

Bartonella henselae lymphadenitis, or cat-scratch lymphadenitis (CSL), is classically associated with stellate microabscesses, occasional giant cells, and extension of the inflammatory infiltrate into perinodal soft tissue. Availability of B. henselae molecular testing on tissue specimens has broadened our understanding of the morphologic variation in this disease. Here we sought to describe the histopathologic features of the largest series to date of molecularly proven CSL. B. henselae polymerase chain reaction-positive tissue specimens from 2010 to 2012 were identified, and hematoxylin and eosin slides were reviewed. A single-step 16S-23S rRNA-based polymerase chain reaction testing was used to identify B. henselae on formalin-fixed, paraffin-embedded tissues. A total of 100 B. henselae-positive cases were identified. The median age of the patients was 26.5 years (range, 1 to 69 y). Ninety-two percent of cases presented in lymph nodes, with 66% of these occurring above the diaphragm, most commonly in the cervical chain. Of 100 cases, 57 had classical CSL features of necrotizing granulomas with microabscesses, with or without surrounding palisading histiocytes. In contrast, 43/100 cases lacked the prototypical microabscesses of CSL including: 23 cases (53.5%) with features of fungal/mycobacterial lymphadenitis, 6 (14%) cases with features of Kikuchi lymphadenitis, and 4 cases (9.3%) with the classic histologic triad of toxoplasma lymphadenitis. In summary, B. henselae lymphadenitis may lack the typical microabscesses in almost half of cases and may closely mimic other reactive, especially infectious, lymphadenopathies. Given the lack of specificity of many of these features, a low threshold for B. henselae molecular testing on tissue is warranted in the appropriate clinical context.

Educational Value of Digital Whole Slides Accompanying Published Online Pathology Journal Articles: A Multi-Institutional Study.

CONTEXT: -Despite great interest in using whole slide imaging (WSI) in pathology practice and education, few pathology journals have published WSI pertinent to articles within their pages or as supplemental materials. OBJECTIVE: -To evaluate whether there is measurable added educational value of including WSI in publications. DESIGN: -Thirty-seven participants, 16 (43.3%), 15 (40.5%), and 6 (16.2%) junior pathology residents (postgraduate year 1-2), senior pathology residents (postgraduate year 3-4), and board-certified pathologists, respectively, read a sequence of 10 journal articles on a wide range of pathology topics. A randomized subgroup also reviewed the WSI published with the articles. Both groups completed a survey tool assessing recall of text-based content and of image-based material pertinent to the diseases but not present in the fixed published images. RESULTS: -The group examining WSI had higher performance scores in 72% of image-based questions (36 of 50 questions) as compared with the non-WSI group. As an internal study control, the WSI group had higher performance scores in only 40% of text-based questions (6 of 15 questions). The WSI group had significantly better performance than the non-WSI group for image-based questions compared with text-based questions (P < .05, Fisher exact test). CONCLUSION: -Our study provides supporting evidence that WSI offers enhanced value to the learner beyond the text and fixed images selected by the author. We strongly encourage more journals to incorporate WSI into their publications.

Expression of Sirt1 and FoxP3 in classical Hodgkin lymphoma and tumor infiltrating lymphocytes: Implications for immune dysregulation, prognosis and potential therapeutic targeting.

BACKGROUND: Hodgkin Reed-Sternberg (HRS) cells may promote differentiation of CD4+ naïve T cells toward both FoxP3+ T regulatory (Treg) cells and TIA-1+ cytotoxic T lymphocytes (CTL). Previous studies suggest that an overabundance of cytotoxic TIA-1+ cells in relation to FoxP3+ T reg cells portends unfavorable outcomes in classical Hodgkin lymphoma (cHL), raising the possibility that its pathogenesis may be related to immune dysregulation. Sirt1 deacetylates FoxP3 and leads to decreased Treg functionality. Our objective was to compare Sirt1 and FoxP3 expressions in Hodgkin lymphoma infiltrating lymphocytes (HLIL) and confirm Sirt1 expression in HRS cells. DESIGN: Immunohistochemical staining of paraffin-embedded tissue with antibodies to Sirt1, FoxP3, TIA-1, and CD8 was performed. Expression of Sirt1 was assessed in both the HRS cells and in the HLILs in twenty-four cases. Adequate tissue was available in 13 cHL cases to permit the enumeration of FoxP3, TIA-1 and CD8 by giving their percent staining of HLILs. RESULTS: In HLILs, nuclear expression of Sirt1 was 32-88% (mean 67%); FoxP3 expression was 9-40% (mean 23.9%); TIA-1 expression was 15-87% (mean 32%); and CD8 expression was 10-45% (mean = 31%). Sirt1 to FoxP3 ratio was 0.96-5.5 (mean 3.2). TIA-1 to FoxP3 ratio was 0.6-5.1 (mean 1.6). CD8 to FoxP3 ratio was 0.43-3.7 (mean 1.5). There was a difference of Sirt1 to FoxP3 ratios between remission and recurrence groups, being significantly higher in the recurrence group (P = 0.005). Sirt1 demonstrated high nuclear expression in the HRS cells of 21 out of 24 (88%) cases analyzed. CONCLUSION: The relative overexpression of Sirt1 to FoxP3 in HLILs may be considered possible targets for immune modulation. Histone deacetylase inhibitors may increase the efficacy of existing treatment regimens by downregulating SIRT1 gene mRNA/Sirt1 protein function and together with rapamycin could expand the T regulatory/FoxP3 population and functionality and improve prognosis for remission in cHL. Targeting Sirt1 in the HRS cells may facilitate their ability to promote naïve T cell differentiation toward Treg cells over CTL.

Interpretation of coagulation test results using a web-based reporting system.

BACKGROUND: Web-based synoptic reporting has been successfully integrated into diverse fields of pathology, improving efficiency and reducing typographic errors. Coagulation is a challenging field for practicing pathologists and pathologists-in-training alike. OBJECTIVE: To develop a Web-based program that can expedite the generation of a individualized interpretive report for a variety of coagulation tests. METHODS: We developed a Web-based synoptic reporting system composed of 119 coagulation report templates and 38 thromboelastography (TEG) report templates covering a wide range of findings. RESULTS: Our institution implemented this reporting system in July 2011; it is currently used by pathology residents and attending pathologists. Feedback from the users of these reports have been overwhelmingly positive. Surveys note the time saved and reduced errors. CONCLUSION: Our easily accessible, user-friendly, Web-based synoptic reporting system for coagulation is a valuable asset to our laboratory services.

Clinicopathologic features of CD5-positive nodal marginal zone lymphoma.

OBJECTIVES: To describe the clinicopathologic findings of seven patients with CD5-positive nodal marginal zone lymphoma (NMZL). METHODS: We searched cases of NMZL over a 10-year interval and identified seven cases of CD5-positive NMZL. The clinical, histologic, and immunophenotypic findings of this group were reviewed, and the frequency of dissemination in this group was compared with that of 66 patients with CD5-negative NMZL. RESULTS: Other than CD5 expression, the histologic and immunophenotypic findings were typical of NMZL. Six (86%) of seven patients had lymphadenopathy above and below the diaphragm, and all six patients assessed had bone marrow involvement. In the CD5-negative group, 28 (42%) patients had lymphadenopathy above and below the diaphragm, and 36 (55%) had bone marrow involvement (P = .045 and P = .037, respectively). Six of seven patients were alive at last follow-up, with a median follow-up of 32 months (3-154 months). CONCLUSIONS: CD5 expression in NMZL correlates with a higher frequency of dissemination, but patients have an indolent clinical course and excellent overall survival.