CD5 expression in NMZL correlates with a higher frequency of dissemination, but patients have an indolent clinical course and excellent overall survival.

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 textbased 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.

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.

Syringolymphoid hyperplasia (SLH) is an extremely rare histopathological entity with fewer than 40 cases reported in the literature. SLH have been seen as both benign lesions and in association with T-cell lymphoproliferative lesions. A 20-year-old male presented with a solitary, infiltrated plaque on the left cheek initially diagnosed as a sebaceous carcinoma at an external institution. A repeat biopsy demonstrated prominent follicular mucinosis (FM), squamous metaplasia of the eccrine coils, and a moderately dense perieccrine lymphocytic infiltrate mimicking eccrine carcinoma. The lesion was subsequently diagnosed as SLH with associated FM, an entity that has been previously reported in 12 cases, including this current case. This case highlights the characteristic features of a rare entity, emphasizes the potential for misdiagnosis of SLH, and adds to the current series of SLH described in the literature.

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