Long-term Prophylaxis Against Aerosolized Marburg Virus in Nonhuman Primates With an Afucosylated Monoclonal Antibody.

Marburg virus (MARV) causes a hemorrhagic fever disease in human and nonhuman primates with high levels of morbidity and mortality. Concerns about weaponization of aerosolized MARV have spurred the development of nonhuman primate (NHP) models of aerosol exposure. To address the potential threat of aerosol exposure, a monoclonal antibody that binds MARV glycoprotein was tested, MR186YTE, for its efficacy as a prophylactic. MR186YTE was administered intramuscularly to NHPs at 15 or 5 mg/kg 1 month prior to MARV aerosol challenge. Seventy-five percent (3/4) of the 15 mg/kg dose group and 50% (2/4) of the 5 mg/kg dose group survived. Serum analyses showed that the NHP dosed with 15 mg/kg that succumbed to infection developed an antidrug antibody response and therefore had no detectable MR186YTE at the time of challenge. These results suggest that intramuscular dosing of mAbs may be a clinically useful prophylaxis for MARV aerosol exposure.

#InSituPathologists: how the #USCAP2015 meeting went viral on Twitter and founded the social media movement for the United States and Canadian Academy of Pathology.

Professional medical conferences over the past five years have seen an enormous increase in the use of Twitter in real-time, also known as "live-tweeting". At the United States and Canadian Academy of Pathology (USCAP) 2015 annual meeting, 24 attendees (the authors) volunteered to participate in a live-tweet group, the #InSituPathologists. This group, along with other attendees, kept the world updated via Twitter about the happenings at the annual meeting. There were 6,524 #USCAP2015 tweets made by 662 individual Twitter users; these generated 5,869,323 unique impressions (potential tweet-views) over a 13-day time span encompassing the dates of the annual meeting. Herein we document the successful implementation of the first official USCAP annual meeting live-tweet group, including the pros/cons of live-tweeting and other experiences of the original #InSituPathologists group members. No prior peer-reviewed publications to our knowledge have described in depth the use of an organized group to "live-tweet" a pathology meeting. We believe our group to be the first of its kind in the field of pathology.

Primary cutaneous perivascular epithelioid cell tumor (PEComa): Five new cases and review of the literature.

PEComas represent a family of uncommon mesenchymal tumors composed of "perivascular epithelioid cells" with a distinct immunophenotype that typically shows both myogenic and melanocytic differentiation. The PEComa family includes angiomyolipoma (AML), clear cell "sugar" tumor of the lung and extra pulmonary sites, lymphangioleiomyomatosis and clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres. Very rarely, PEComas may arise in the skin. Primary cutaneous PEComas typically display a dermal proliferation of epithelioid cells with pale, clear, or granular pink cytoplasm arranged in nests and trabecula with an intervening arborizing network of delicate capillaries. Primary cutaneous PEComas have a lower frequency of myogenic marker expression than their deep soft tissue and visceral counterparts. They also often express strong diffuse CD10, leading to potential confusion with metastatic renal cell carcinoma. Most cases behave indolently. We report 5 additional cases of this rare entity. All showed classic histologic features and expression of either HMB-45 and/or Melan-A/MART-1. Four cases were tested for myogenic markers (2 were positive & 2 were negative). Three cases were tested for CD10 (all 3 were positive). All of our cases with clinical follow-up behaved indolently. Table 1 provides a summary of findings for all 5 cases in our series.

Discordance of histopathologic parameters in cutaneous melanoma: Clinical implications.

BACKGROUND: Histopathologic analysis remains the gold standard for the diagnosis of melanoma, however previous studies have shown a substantial rate of interobserver variability in the evaluation of melanocytic lesions. OBJECTIVE: We sought to evaluate discordance in the histopathological diagnosis and microstaging parameters of melanoma and subsequent impact on clinical management. METHODS: This was a retrospective review of 588 cases of cutaneous melanoma and melanoma in situ from January 2009 to December 2014 that were referred to Emory University Hospital, Atlanta, GA, for treatment. Per institutional policy, all outside melanoma biopsy specimens were reviewed internally. Outside and institutional reports were compared. RESULTS: Disagreement between outside and internal reports resulted in a change in American Joint Committee on Cancer pathologic stage in 114/588 (19%) cases, resulting in a change in management based on National Comprehensive Cancer Network guidelines in 105/588 (18%) cases. LIMITATIONS: Given the retrospective nature of data collection and the bias of a tertiary care referral center, cases in this study may not be representative of all melanoma diagnoses. CONCLUSION: These findings confirm consistent subjectivity in the histopathologic interpretation of melanoma. This study emphasizes that a review of the primary biopsy specimen may lead to significant changes in tumor classification, resulting in meaningful changes in clinical management.

Benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma: A case report expanding the clinical and histopathologic features of a recently described entity.

Benign cutaneous plexiform hybrid tumor of perineurioma and cellular neurothekeoma (BCPHTPCN) is a recently described entity that presents as a solitary papule in the perioral area. As implied by its name, BCPHTPCN displays microscopic features of both perineurioma and cellular neurothekeoma arranged in a plexiform pattern. We report a case of nonplexiform benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma in a 36-year-old woman, who presented with a 4-year history of a firm, flesh-colored left ankle nodule. Histologically, there was a biphasic, well-circumscribed unencapsulated dermal mesenchymal proliferation with no connection to the epidermis, which exhibited mild acanthosis with slightly pigmented basal keratinocytes and overlying parakeratosis. The proliferation consisted of uniform bland spindle cells with bipolar cytoplasmic processes arranged in whorls with interspersed islands of epithelioid cells. Immunohistochemically, the spindle cell component was positive for CD34, EMA, and GLUT-1, consistent with perineurial differentiation, whereas the epithelioid nests were positive for NKI/C3 and MiTF, as expected in neurothekeoma. Stains for S100 protein, SOX10, desmin, claudin, pan-melanoma markers, and NSE were negative. We believe this case expands the histopathologic spectrum of BCPHTPCN showing that it can be grown in a nonplexiform pattern, and we suggest the term benign cutaneous biphasic hybrid tumor of perineurioma and cellular neurothekeoma as a more precise name. It is also, to the best of our knowledge, the first case reported outside the head and neck area.

Blastic Plasmacytoid Dendritic Cell Neoplasm in the Pediatric Population: A Case Series and Review of the Literature.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive hematologic malignancy primarily found in adults, often carrying a poor prognosis. There are only 33 reported pediatric cases of BPDCN in the literature. Although standard treatment is not yet established for children, current literature recommends the use of high-risk acute lymphoblastic leukemia (ALL)-type chemotherapy. Recent studies, however, have explored the benefits of combining chemotherapy with stem-cell transplantation. Here, the authors present 2 cases of pediatric BPDCN treated with different modalities. The first case is a 13-year-old girl who presented with a 3-month history of an initially asymptomatic firm nodule on her left shin. The second case is a 15-year-old boy who presented with a 4-month history of an enlarging subcutaneous nodule on the lower leg. Immunohistochemical staining of both patients was positive for markers consistent with BPDCN. The latter patient received ALL-type therapy alone, whereas the former received ALL-type chemotherapy and stem-cell transplantation. Since initial treatment, both patients remain disease-free. These cases contribute to the limited number of pediatric BPDCN cases, thus helping to advance our knowledge toward an optimal treatment protocol for clinical remission.

Utility of additional tissue sections in dermatopathology: diagnostic, clinical and financial implications.

BACKGROUND: As histopathologic assessment is subject to sampling error, some institutions 'preorder' deeper sections on some or all cases (hereafter referred to as prospective deeper sections), while others order additional sections only when needed (hereafter referred to as retrospective deeper sections). We investigated how often additional sections changed a diagnosis and/or clinical management. Given the recent decrease in reimbursement for CPT-code 88305, we also considered the financial implications of ordering additional sections. METHODS: Cases (n = 204) were assigned a preliminary diagnosis, based on review of the initial slide, and a final diagnosis, after reviewing additional sections. Cases with discordant diagnoses were assessed by two dermatologists, who indicated whether the change in diagnosis altered clinical management. Expenses were estimated for three scenarios: (a) no additional sections, (b) prospective deeper sections and (c) retrospective deeper sections. RESULTS: Diagnoses were modified in 9% of cases, which changed clinical management in 56% of these cases. Lesions obtained by punch-biopsy and inflammatory lesions were disproportionately overrepresented amongst cases with changed diagnoses (p < 0.001, p = 0.12, respectively). The cost of prospective deeper sections and retrospective deeper sections represented a 56% and 115% increase over base costs, respectively. Labor costs, particularly the cost of dermatopathologist evaluation, were the most significant cost-drivers. CONCLUSIONS: While additional sections improve diagnostic accuracy, they delay turn-around-time and increase expenditures. In our practice, prospective deeper sections are cost effective, however, this may vary by institution.

Production and Purification of Antibodies in Chinese Hamster Ovary Cells.

Antibodies are versatile biological molecules with widespread applications in research and medicine. This protocol outlines the generation of monoclonal IgG antibodies from Chinese hamster ovary cells. It includes steps for cell maintenance, transient transfection, and antibody purification via protein A affinity chromatography. The methods described are intended for the production of milligram amounts of protein but can be adapted for most small- to mid-scale applications.

Hyperdiluted Botulinum Toxin and Intense Pulsed Light Treatment: A Case Series to Illustrate a Novel Protocol for Hypertrophic Scar Reduction.

Hypertrophic scars can have significant and far-reaching effects on patients that range from itching to creating difficulty with mobility, all of which can negatively impact the individual's quality of life. A recent study showed that many patients with recent scars report pain, burning, pruritus, erythema, in combination with psychological difficulties that impact bodily movement, choice of clothing, and participation in leisure activities. Botulinum toxin Type A (BoNTA) and intense pulsed light (IPL) have shown promise in treating such scars. We propose a novel treatment protocol involving a 4-week intervention with hyperdiluted BoNTA injections and supplemental treatment with IPL for erythema, and a 6-month scar scale assessment and photographic documentation that occurs before and 6 months after treatment. We report four cases where using hyperdiluted BoNTA, either alone or in conjunction with IPL, substantially reduced scar size, improved overall scar appearance, and diminished erythema in areas on the face and the breasts. Although this report suggests that a schedule of alternating treatments with BoNTA and IPL may be beneficial in reducing scar size and enhancing appearance, further research is necessary to better understand the most effective dosages, the relationship between BoNTA and IPL, and the optimal management of scarring.

Antibodies targeting Crimean-Congo hemorrhagic fever virus GP38 limit vascular leak and viral spread.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a priority pathogen transmitted by tick bites, with no vaccines or specific therapeutics approved to date. Severe disease manifestations include hemorrhage, endothelial dysfunction, and multiorgan failure. Infected cells secrete the viral glycoprotein GP38, whose extracellular function is presently unknown. GP38 is considered an important target for vaccine and therapeutic design as GP38-specific antibodies can protect against severe disease in animal models, albeit through a currently unknown mechanism of action. Here, we show that GP38 induces endothelial barrier dysfunction in vitro, and that CCHFV infection, and GP38 alone, can trigger vascular leak in a mouse model. Protective antibodies that recognize specific antigenic sites on GP38, but not a protective neutralizing antibody binding the structural protein Gc, potently inhibit endothelial hyperpermeability in vitro and vascular leak in vivo during CCHFV infection. This work uncovers a function of the secreted viral protein GP38 as a viral toxin in CCHFV pathogenesis and elucidates the mode of action of non-neutralizing GP38-specific antibodies.

Therapeutic administration of a cross-reactive mAb targeting the fusion glycoprotein of Nipah virus protects nonhuman primates.

No licensed vaccines or therapies exist for patients infected with Nipah virus (NiV), although an experimental human monoclonal antibody (mAb) cross-reactive to the NiV and Hendra virus (HeV) G glycoprotein, m102.4, has been tested in a phase 1 trial and has been provided under compassionate use for both HeV and NiV exposures. NiV is a highly pathogenic zoonotic paramyxovirus causing regular outbreaks in humans and animals in South and Southeast Asia. The mortality rate of NiV infection in humans ranges from 40% to more than 90%, making it a substantial public health concern. The NiV G glycoprotein mediates host cell attachment, and the F glycoprotein facilitates membrane fusion and infection. We hypothesized that a mAb against the prefusion conformation of the F glycoprotein may confer better protection than m102.4. To test this, two potent neutralizing mAbs against NiV F protein, hu1F5 and hu12B2, were compared in a hamster model. Hu1F5 provided superior protection to hu12B2 and was selected for comparison with m102.4 for the ability to protect African green monkeys (AGMs) from a stringent NiV challenge. AGMs were exposed intranasally to the Bangladesh strain of NiV and treated 5 days after exposure with either mAb (25 milligrams per kilogram). Whereas only one of six AGMs treated with m102.4 survived until the study end point, all six AGMs treated with hu1F5 were protected. Furthermore, a reduced 10 milligrams per kilogram dose of hu1F5 also provided complete protection against NiV challenge, supporting the upcoming clinical advancement of this mAb for postexposure prophylaxis and therapy.

Epithelioid sarcoma-like (pseudomyogenic) hemangioendothelioma, clinically mimicking dermatofibroma, diagnosed by skin biopsy in a 30-year-old man.

Epithelioid sarcoma-like (pseudomyogenic) hemangioendothelioma (ESHE) represents a rare soft tissue and bone tumor that typically presents as nodule(s) in the distal extremities of young adults. The nodules traverse several tissue planes simultaneously and can involve the dermis, subcutis, skeletal muscle and bone. ESHE shares clinical and microscopic features with epithelioid sarcoma (ES), and, accordingly, is commonly misdiagnosed as ES. However, unlike ES, which has a poor prognosis, ESHE commonly follows an indolent course. Herein, we report a case of ESHE diagnosed by skin biopsy that clinically mimicked a dermatofibroma. We also provide clinical photographs of the lesions in various stages of development, representing information that has not been previously published, to our knowledge.

Reversion of Ebolavirus Disease from a Single Intramuscular Injection of a Pan-Ebolavirus Immunotherapeutic.

Intravenous (IV) administration of antiviral monoclonal antibodies (mAbs) can be challenging, particularly during an ongoing epidemic, due to the considerable resources required for performing infusions. An ebolavirus therapeutic administered via intramuscular (IM) injection would reduce the burdens associated with IV infusion and allow rapid treatment of exposed individuals during an outbreak. Here, we demonstrate how MBP134, a cocktail of two pan-ebolavirus mAbs, reverses the course of Sudan ebolavirus disease (Gulu variant) with a single IV or IM dose in non-human primates (NHPs) as late as five days post-exposure. We also investigate the utility of adding half-life extension mutations to the MBP134 mAbs, ultimately creating a half-life extended cocktail designated MBP431. When delivered as a post-exposure prophylactic or therapeutic, a single IM dose of MBP431 offered complete or significant protection in NHPs challenged with Zaire ebolavirus. In conjunction with previous studies, these results support the use of MBP431 as a rapidly deployable IM medical countermeasure against every known species of ebolavirus.

Cutaneous myoepithelial carcinoma with disseminated metastases.

Primary cutaneous neoplasms of myoepithelial differentiation are uncommon. Cutaneous myoepithelial carcinomas are rare. We report a case of cutaneous myoepithelial carcinoma in a 47-year-old man with a history of end-stage renal disease and renal transplant 19 years prior who presented to the hospital with a 3-month history of diffuse bone pain and an ulcerated scalp mass with multiple satellite lesions. This case illustrates a rare instance of metastatic disease from primary cutaneous myoepithelial carcinoma.

Analytic Validation of Immunohistochemistry Assays: New Benchmark Data From a Survey of 1085 Laboratories.

CONTEXT: - A cooperative agreement between the College of American Pathologists (CAP) and the United States Centers for Disease Control and Prevention was undertaken to measure laboratories' awareness and implementation of an evidence-based laboratory practice guideline (LPG) on immunohistochemical (IHC) validation practices published in 2014. OBJECTIVE: - To establish new benchmark data on IHC laboratory practices. DESIGN: - A 2015 survey on IHC assay validation practices was sent to laboratories subscribed to specific CAP proficiency testing programs and to additional nonsubscribing laboratories that perform IHC testing. Specific questions were designed to capture laboratory practices not addressed in a 2010 survey. RESULTS: - The analysis was based on responses from 1085 laboratories that perform IHC staining. Ninety-six percent (809 of 844) always documented validation of IHC assays. Sixty percent (648 of 1078) had separate procedures for predictive and nonpredictive markers, 42.7% (220 of 515) had procedures for laboratory-developed tests, 50% (349 of 697) had procedures for testing cytologic specimens, and 46.2% (363 of 785) had procedures for testing decalcified specimens. Minimum case numbers were specified by 85.9% (720 of 838) of laboratories for nonpredictive markers and 76% (584 of 768) for predictive markers. Median concordance requirements were 95% for both types. For initial validation, 75.4% (538 of 714) of laboratories adopted the 20-case minimum for nonpredictive markers and 45.9% (266 of 579) adopted the 40-case minimum for predictive markers as outlined in the 2014 LPG. The most common method for validation was correlation with morphology and expected results. Laboratories also reported which assay changes necessitated revalidation and their minimum case requirements. CONCLUSIONS: - Benchmark data on current IHC validation practices and procedures may help laboratories understand the issues and influence further refinement of LPG recommendations.

Analytic Validation of Immunohistochemical Assays: A Comparison of Laboratory Practices Before and After Introduction of an Evidence-Based Guideline.

CONTEXT: - Laboratories must demonstrate analytic validity before any test can be used clinically, but studies have shown inconsistent practices in immunohistochemical assay validation. OBJECTIVE: - To assess changes in immunohistochemistry analytic validation practices after publication of an evidence-based laboratory practice guideline. DESIGN: - A survey on current immunohistochemistry assay validation practices and on the awareness and adoption of a recently published guideline was sent to subscribers enrolled in one of 3 relevant College of American Pathologists proficiency testing programs and to additional nonsubscribing laboratories that perform immunohistochemical testing. The results were compared with an earlier survey of validation practices. RESULTS: - Analysis was based on responses from 1085 laboratories that perform immunohistochemical staining. Of 1057 responses, 65.4% (691) were aware of the guideline recommendations before this survey was sent and 79.9% (550 of 688) of those have already adopted some or all of the recommendations. Compared with the 2010 survey, a significant number of laboratories now have written validation procedures for both predictive and nonpredictive marker assays and specifications for the minimum numbers of cases needed for validation. There was also significant improvement in compliance with validation requirements, with 99% (100 of 102) having validated their most recently introduced predictive marker assay, compared with 74.9% (326 of 435) in 2010. The difficulty in finding validation cases for rare antigens and resource limitations were cited as the biggest challenges in implementing the guideline. CONCLUSIONS: - Dissemination of the 2014 evidence-based guideline validation practices had a positive impact on laboratory performance; some or all of the recommendations have been adopted by nearly 80% of respondents.

Cytologic features of angiosarcoma: A review of 26 cases diagnosed on FNA.

BACKGROUND: This study describes the cytologic features of 26 angiosarcomas diagnosed on fine-needle aspiration. METHODS: Twenty-six angiosarcomas from 20 patients were confirmed by cytomorphology and immunocytochemical (immunohistochemistry) positivity for at least 2 of 3 vascular markers. Specimens were examined for spindled/epithelioid/plasmacytoid single cells, 3-dimensional clusters, multiple prominent/bar-shaped nucleoli (5 times longer than their width), chromatin strands, abnormal mitoses, necrosis, and vasoformative features. RESULTS: Eight males and 12 females with a mean age of 52 years (range, 2-94 years) underwent aspiration of tumors in the following: soft tissue or skin/subcutis (n = 10), bone (n = 4), nodes (n = 5), lung (n = 2), liver (n = 2), heart (n = 1), parotid gland (n = 1), and pleural fluid (n = 1). An angiosarcoma diagnosis was rendered for 24 of the 26 cases (92%); 1 was diagnosed as "atypical cells, cannot exclude angiosarcoma," and another was diagnosed as a malignant vascular neoplasm. Abnormal mitoses were most frequent (85%), and they were followed by single malignant cells (81%: epithelioid [69%], spindled [62%], and plasmacytoid [19%]), 3-dimensional clusters (54%), multiple prominent (62%) or bar-shaped nucleoli (54%), and chromatin strands (31%). Vasoformative features, including hemophagocytosis (54%), cytoplasmic lumina/vacuoles (69%) containing red blood cells (54%)/neutrophils (31%), and endothelial wrapping (69%), were seen in 88%; 23% had all vasoformative features, 88% had at least 1, and 12% had none. CONCLUSIONS: Angiosarcomas show a range of cytomorphologic features that make them potentially recognizable on cytology. Although vasoformative features are highly suggestive, they are not specific for angiosarcoma and may be seen in some nonvascular neoplasms. Immunohistochemistry and a high index of suspicion are required for an accurate diagnosis. Cancer Cytopathol 2016;124:659-68. © 2016 American Cancer Society.

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.