Jože Pižem

Zika Virus-Associated Micrencephaly: A Thorough Description of Neuropathologic Findings in the Fetal Central Nervous System.

CONTEXT -The 2015 outbreak of Zika virus in Brazil resulted in a 20-times increased prevalence of congenital microcephaly in stillborns and neonates and was instrumental in raising the suspicion of a causal association between Zika virus and microcephaly. OBJECTIVE -To provide a comprehensive description of the neuropathologic features of congenital Zika virus infection. DESIGN -Autopsy evaluation of the brain from a fetus of 32 weeks and 6 days of gestation, with a prenatal diagnosis of microcephaly associated with polymerase chain reaction-confirmed, fetal, Zika virus infection. RESULTS -Multiple severe pathology findings were present. These included lissencephaly, except for the occipital lobes, where some pachygyria was observed. Also present was reduction and thinning of white matter, ventriculomegaly of the lateral ventricles, and coalescent calcifications in the cortical-subcortical white matter border associated with glioneuronal outbursting into the subarachnoid space above and heterotopias below. There were small, scattered calcifications in the basal ganglia, with fewer in the white matter and germinal matrix, and none in the cerebellum and brainstem. The cerebellum and pontine base were atrophic because of Wallerian degeneration or maldevelopment of descending tracts and pontocerebellar connections. CONCLUSION -Our findings are in agreement with neuroimaging of Zika virus-associated fetal and infant micrencephalic brains and, to some extent, with neuroimaging of other intrauterine infections causing microcephaly.

Proliferative and apoptotic activity in hepatocellular carcinoma and surrounding non-neoplastic liver tissue

Abstract The aim of the study was to determine the proliferative and apoptotic activity of neoplastic and non-neoplastic hepatocytes, to ascertain whether there was a correlation between the histopathological characteristics of hepatocellular carcinoma (HCC) and its proliferative or apoptotic activity. Methods. One tumour sample and one sample of non-neoplastic liver from 16 patients with HCC were analysed. The proliferative activity was established by immunohistochemical staining against PCNA (proliferating cell nuclear antigen) and Ki-67. Apoptotic activity was determined by morphological and TUNEL methods. Bcl-2 immunoreactivity was analysed. Results. A positive correlation between PCNA and Ki-67 proliferative indexes was found in HCC (p<0.01). The PCNA index was 0.21%± 0.80% (Mean ± SD) in non-neoplastic liver and 7.41%± 8.22% in HCC, while the Ki-67 index was 0.19%± 0.26% in non-neoplastic liver and 9.67%± 7.70% in HCC. The differences between HCC and non-neoplastic liver were significant (p<0.05). The PCNA index differed significantly between different HCC grades (p<0.05). In HCC and non-neoplastic liver samples, apoptotic indexes (AI) assessed morphologically were higher than AI determined by the TUNEL method. Differences in AI (irrespective of the method used) between different HCC grades were not significant. Bcl-2 staining was positive in one non-neoplastic liver sample (6.3%) and in 4 HCC samples (25%). Conclusions. PCNA and Ki-67 were useful for proliferative activity assessment of hepatocytes. There were no differences in apoptotic activity between HCC and non-neoplastic tissue, so it seems that uncontrolled tumour cell division plays an important role in HCC growth. In the regulation of the apoptotic process in HCC, Bcl-2 could be important.

Cutaneous Pseudolymphoma Following Tattoo Application: Report of Two New Cases of a Potential Lymphoma Mimicker

The authors report 2 cases of cutaneous pseudolymphoma that occurred in 2 young adult patients who referred for relentlessly growing nodules that appeared within 4 to 5 months after the application of a mercury-based tattoo. Systemic symptoms were not present and there was no evidence of lymph node enlargement. Clinically, both lesions were limited to the red, mercury-based areas of the tattoo. Microscopic examination featured a dense cellular infiltrate composed of polytypic T cells in the upper to mid-dermis, coupled with focal interface tissue reaction. Scattered macrophages contained finely granular particles in their cytoplasm. In addition, extracellular pigment particles were also recognized. Collections of epithelioid macrophages were present in both cases and were reminiscent of epithelioid granulomas. This study confirms evidence that, among skin diseases featuring a dense lymphoid infiltrate, cutaneous pseudolymphoma secondary to tattooing is a rare but not exceptional source of diagnostic challenges.

Melanocytic differentiation is present in a significant proportion of nonpigmented diffuse neurofibromas: A potential diagnostic pitfall

Whereas the pigmented (melanotic) variant of diffuse neurofibroma (DNF) with positivity for melanocytic markers is well recognized, expression of melanocytic markers in nonpigmented DNF has not been systematically studied. We analyzed 28 unselected consecutive DNFs for expression of melanocytic markers, including melan A, microphthalmia transcription factor (MITF), and HMB-45 antigen. For comparison, we also analyzed 40 localized skin neurofibromas and 7 intraneural neurofibromas. One case of nonpigmented DNF was analyzed by electron microscopy. Of the 28 DNFs studied by immunohistochemistry, 3 were pigmented and 25 nonpigmented. The 3 pigmented DNFs and 9 of 25 (36%) nonpigmented DNFs expressed melan A, MITF, and HMB-45 antigen. These markers were expressed either focally or more diffusely, typically in a minority of the lesional cells, and usually both in the dermal and subcutaneous portion of the DNF. Melan A was expressed in the largest number of the lesional cells (up to 50%), whereas only a small fraction of the melan A-positive cells (from 5% to 10% in most cases) also expressed HMB-45 antigen. None of the 47 non-DNFs expressed these markers. Ultrastructurally, melanosomes were present in some cells in nonpigmented DNF that expressed the melanocytic markers. Twenty-three of 28 (82%) DNFs, including 10 of 12 (83%) DNFs with melanocytic differentiation, were associated with neurofibromatosis type 1. Expression of melanocytic markers, including melan A, HMB-45 antigen, and MITF in DNF is a potential pitfall in differential diagnosis with melanocytic lesions that may clinically or histopathologically resemble DNF, in particular congenital melanocytic nevus with neurotization and neurofibroma-like melanoma.

Immunohistochemical analysis of pro- and active-caspase 3 in laryngeal squamous cell carcinoma.

Active caspase 3 is considered to be the main executioner caspase in apoptotic process. The mechanisms of apoptosis in laryngeal squamous cell carcinoma (LSCC) have been investigated by examining the expression profiles of pro-caspase 3 and active-caspase 3. The correlation between the two forms of caspase 3 and the p53 status was also determined. LSCCs (n=65) were studied using immunohistochemistry with antibodies to pro-caspase 3, active-caspase 3 and p53. The expression of pro-caspase 3 was absent or weak in 16 (24.6%), moderate in 21 (32.3%) and strong in 28 (43.1%) cases. Survival curves for different levels of pro-caspase 3 differed, but the differences were not statistically significant. An apoptotic index (AI) was determined by quantifying the active-caspase 3-positive cells. The AI ranged from 0.2% to 9.4% and did not differ among the different levels of pro-caspase 3 expression. Even in cases in which the expression of pro-caspase 3 was considered negative, caspase 3-positive apoptotic cells were found. The AIs were significantly higher in supraglottic tumours compared with glottic counterparts (P=0.008) and were higher in poorly differentiated tumours compared with well-differentiated and moderately differentiated LSCC (P=0.06). No correlation between AI and p53 expression was found, although pro-caspase 3 expression trended to be higher in the p53-positive group of LSCC. Our results suggest that the expression of pro-caspase 3, a key executioner caspase in apoptosis, is downregulated in a proportion of LSCC, but this is not associated with decreased apoptotic activity, measured by active-caspase 3 labelling.

Morphological characteristics of conjunctival squamous papillomas in relation to human papillomavirus infection

Objective To determine the prevalence of a broad spectrum of human papillomavirus (HPV) types in conjunctival papillomas and a possible difference in clinical and histopathological presentation of HPV-positive and HPV-negative papillomas. Methods Formalin-fixed, paraffin-embedded papilloma tissue specimens obtained from 25 patients were analysed using six different PCR-based methods targeting 87 HPV types from four different papillomavirus (PV) genera: α-PV, β-PV, γ-PV and µ-PV, and in situ hybridisation for HPV-6/HPV-11. Slides were reviewed for pedunculated or sessile growth, the presence of goblet cells, keratinising or non-keratinising epithelium, elastosis, atypia and koilocytes. Results α-PV types HPV-6 and HPV-11 were detected in 19/25 (76%) conjunctival papilloma tissue specimens, 9 (47%) of which were also HPV-6/HPV-11 positive with in situ hybridisation. Six different β-PV types—HPV-9, HPV-12, HPV-20, HPV-21, HPV-22, HPV-24—were additionally detected in four cases, all of which were also HPV-6/HPV-11 positive. No γ-PVs or µ-PVs were found in any of the tested tissues samples. Extralimbal location (p=0.021), presence of goblet cells (p=0.005), non-keratinising squamous epithelium (p=0.005), and absence of elastosis (p=0.005) were associated with the presence of HPV-6/HPV-11. Conclusions We demonstrated that certain clinical and histological features are more frequently associated with HPV infection and that HPV genera other than α-PV are most probably not significant factors in conjunctival papilloma occurrence.

Melanocytic lesions with eczematous reaction (Meyerson's phenomenon) - a histopathologic analysis of 64 cases.

Eczematous (spongiotic) reaction in melanocytic lesions (Meyersons phenomenon) has not been systematically analyzed and has not been convincingly documented in melanoma.

Is survivin expression prognostic or predictive in malignant pleural mesothelioma

Malignant pleural mesothelioma is an incurable cancer strongly associated with asbestos exposure and characterised by poor response to treatment. The inhibitor-of-apoptosis protein family member survivin is involved in apoptosis and proliferation and is expressed in cancer cells only. The aims of the present study were to elucidate whether survivin expression is associated with tumour cell apoptosis and proliferation and to assess the prognostic and predictive value of survivin expression in malignant pleural mesothelioma. Archival pleural mesothelioma tissue samples from 101 patients were immunohistochemically analysed for nuclear expression of survivin, for proliferation with the use of Ki-67 as marker and for apoptosis using active caspase-3 as a marker. Staining results and clinical data were included in a survival analysis. Survivin was highly expressed in tumour cell nuclei in all samples and this correlated positively with both apoptosis and proliferation, but did not have a significant prognostic value. We found significantly higher survivin expression in patients who responded to chemotherapy compared to patients with progressive disease. Survivin expression might contribute to treatment response prediction, but survivin expression in malignant pleural mesothelioma did not have prognostic significance.

SAT0283 The Incidence of GIANT Cell Arteritis in Slovenia

Background Giant cell arteritis (GCA) is the most common systemic vasculitis in adults aged 50 years or above. Annual incidence rates vary widely from 6.9–76.6 per 105 of adults in this age group, depending on the region.1 Objectives To determine the incidence rate of GCA in our population. Methods We prospectively collected incident cases of GCA from January 1st 2011 to December 31st 2012 at our department of rheumatology which is a part of an integrated secondary/tertiary university teaching hospital that is the only referral center serving a region representing approximately a quarter of the national adult population. Additionally, newly diagnosed cases of GCA between January 1st 2009 and December 31st 2010 were retrospectively identified by searching the electronic patient records for ICD-10 codes M31.5 and M31.6 at our department. The retrospective approach and search strategy was also applied on electronic medical records at the departments of infectious diseases and ophthalmology between January 1st 2009 and December 31st 2012. To further reduce possibility of underreporting, the attached medical facultys Institute of Pathology provided a list of all temporal artery biopsies examined during the observation period which were then cross-referenced with the hospitals electronic medical records. Annual incidence rate for GCA was then calculated. Results During the four year observation period we identified 97 new cases of GCA (68% female; mean (SD) age 75.6 (8.1) years) from a well-defined adult white Caucasian population of 232,041 inhabitants aged 50 or above. The temporal artery biopsy was consistent with GCA, negative or not performed in 75.3%, 18.6, and 6.2% of cases, respectively. Thus, the annual incidence of GCA in our population is 10.5 (95% CI 8.5–12.7), and 4.7 (95% CI 3.8–5.7) per 105 adults aged 50, and 20 years or above, respectively. Conclusions The annual incidence rate of 10.5 per 105 adults aged 50 or above makes GCA the most common systemic vasculitis in this age group of our population. Although the GCA almost exclusively affects adults over 50 years of age, the incidence rate of 4.7 per 105 adults aged 20 and above, also makes it the most common systemic vasculitis in the adult population overall, with IgA vasculitis coming a close second with 3.7 per 105 adults aged 20 years or above. References Gonzalez-Gay MA, Vazquez-Rodriguez TR, Lopez-Diaz MJ et al. Epidemiology of Giant Cell Arteritis and Polymyalgia Rheumatica. Arthritis Rheum 2009;61:1454-61. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1968

Primary aneurysmal bone cyst with a novel SPARC-USP6 translocation identified by next-generation sequencing

Aneurysmal bone cyst (ABC) is a benign but locally aggressive, mostly pediatric neoplasm, with characteristic USP6 gene rearrangement that distinguishes it from a secondary ABC and other primary bone tumors. With the advent of next-generation sequencing (NGS) technology, several hitherto unknown USP6 fusion partners have been identified in ABC. Accordingly, we present a case of an 18-year-old male with a solid sub-periosteal primary ABC in the diaphysis of the left femur. Using an NGS-based assay, we identified SPARC-USP6 fusion, which has not previously been described in ABC. Including our case, the list of currently known USP6 fusion partners in primary ABC include: CDH11, CNBP, COL1A1, CTNNB1, EIF1, FOSL2, OMD, PAFAH1B1, RUNX2, SEC31A, SPARC, STAT3 and THRAP3.