Equine pastern vasculitis: a clinical and histopathological study.

Equine pastern vasculitis is clinically challenging and the underlying aetiopathogenesis is unclear. The aims of this retrospective study were to establish histopathological criteria for pastern vasculitis, to look for an underlying cause, to investigate whether the histopathological lesions are associated with a distinct clinical picture, to assess if and how the clinical picture varies, and to determine the treatment response. Skin biopsies and clinical data from 20 horses with a diagnosis of vasculitis of the distal extremities were investigated and histology was compared to biopsies from healthy horses. It was concluded that intramural inflammatory cells, leukocytoclasia with nuclear dust, thickening and oedema of the vessel walls, and microhaemorrhages are highly specific histological findings in equine pastern vasculitis. Based on the feedback from the clinicians, the lesions were mostly seen on the lateral and medial aspects of un-pigmented legs. Lesions in white skin were characterised by exudation and crusts, whereas those in pigmented skin were alopecic and characterised by scaling. The response to treatment was poor and the prognosis guarded. No association was found between any of the histopathological findings and a distinct clinical picture. An underlying cause of equine pastern vasculitis could not be identified. Considering the large number of confounding factors, the causative agents are difficult to identify, but may involve drugs or a hypersensitivity reactions to yet unknown antigens.

Interim endoscopy results during neoadjuvant therapy for gastric cancer correlate with histopathological response and prognosis

BACKGROUND Neoadjuvant chemotherapy for locally advanced gastric cancer leads to major histopathological response in less than 30 % of patients. Data on interim endoscopic response assessment do not exist. This exploratory prospective study evaluates early endoscopy after 50 % of the chemotherapy as predictor for later response and prognosis. METHODS Forty-seven consecutive patients were included (45 resected; 33 R0 resections). All patients received baseline endoscopy and CT scans, after 50 % of their chemotherapy (EGD-1, CT-1) and after completion of chemotherapy (EGD-2, CT-2). Interim endoscopic response (EGD-1) was assessed after having received 50 % (6 weeks) of the planned 12 weeks of neoadjuvant chemotherapy. Post-chemotherapy response was clinically assessed by a combination of CT scan (CT-2) and endoscopy (EGD-2). Histopathological response was determined by a standardized scoring system (Becker criteria). Endoscopic response was defined as a reduction of >75 % of the tumor mass. RESULTS Twelve patients were responders at EGD-1 and 13 at EGD-2. Nine patients (19.1 %) were clinical responders and 7 patients (15.6 %) were histopathological responders after chemotherapy. Specificity, accuracy, and negative predictive value of the interim EGD-1 for subsequent histopathological response were 31/38 (82 %), 36/47 (76 %), and 31/33 (93 %); and for recurrence or death, 28/30 (93.3 %), 38/47 (80.9 %), and 28/35 (80.0 %). Response at EGD-1 was significantly associated with histopathological response (p = 0.010), survival (p < 0.001), and recurrence-free survival (p = 0.009). CONCLUSIONS Interim endoscopy after 6 weeks predicts response and prognosis. Therefore, tailoring treatment according to interim endoscopic assessment could be feasible, but the findings of this study should be validated in a larger patient cohort.

Pulsed versus continuous wave CO2 laser excisions of 100 oral fibrous hyperplasias: a randomized controlled clinical and histopathological study

BACKGROUND In experimental animal studies, pulsing the CO2 laser beam has been shown to reduce the thermal damage zone of excised oral mucosal tissue. However, there is still controversy over whether this is borne out under clinical conditions. OBJECTIVE To compare the outcome following excisional biopsies of fibrous hyperplasias using a pulsed (cf) versus a continuous wave (cw) CO2 laser mode regarding the thermal damage zone, duration of surgeries, intra- and postoperative complications, postoperative pain sensation, scarring and/or relapse during the initial 6 months. MATERIALS AND METHODS One hundred Swiss-resident patients with a fibrous hyperplasia in their buccal mucosa were randomly assigned to the cw mode (5 W) or the cf mode (140 Hz, 400 microseconds, 33 mJ, 4.62 W) group. All excisions were performed by one single oral surgeon. Postoperative pain (2 weeks) was recorded by visual analogue scale (VAS; ranging from 0 to 100). Intake of analgesics and postoperative complications were recorded in a standardized study form. The maximum width of the collateral thermal damage zone was measured (µm) in excision specimens by one pathologist. Intraoral photographs at 6-month follow-up examinations were evaluated regarding scarring (yes/no). RESULTS Median duration of the excision was 65 seconds in the cw and 81 seconds in the cf group (P = 0.13). Intraoperative bleeding occurred in 16.3% of the patients in the cw and 17.7% of the cf group. The median value of the thermal damage zone was 161(±228) μm in the cw and 152(± 105) μm in the cf group (P = 0.68). The reported postoperative complications included swelling in 19% and minor bleeding in 6% without significant differences between the two laser modes. When comparing each day separately or the combined mean VAS scores of both groups between Days 1-3, 1-7, and 1-15, there were no significant differences. However, more patients of the cw group (25%) took analgesics than patients of the cf group (9.8%) resulting in a borderline significance (P = 0.04). Scarring at the excision site was found in 50.6% of 77 patients after 6 months, and more scars were identified in cases treated with the cf mode (P = 0.03). CONCLUSIONS Excision of fibrous hyperplasias performed with a CO2 laser demonstrated a good clinical outcome and long-term predictability with a low risk of recurrence regardless of the laser mode (cf or cw) used. Scarring after 6 months was only seen in 50.6% of the cases and was slightly more frequent in the cf mode group. Based on the findings of the present study, a safety border of 1 mm appears sufficient for both laser modes especially when performing a biopsy of a suspicious soft tissue lesion to ensure a proper histopathological examination.

Prognostic value of histopathological regression in 850 neoadjuvantly treated oesophagogastric adenocarcinomas.

BACKGROUND Recently, histopathological tumour regression, prevalence of signet ring cells, and localisation were reported as prognostic factors in neoadjuvantly treated oesophagogastric (junctional and gastric) cancer. This exploratory retrospective study analyses independent prognostic factors within a large patient cohort after preoperative chemotherapy including clinical and histopathological factors. METHODS In all, 850 patients presenting with oesophagogastric cancer staged cT3/4 Nany cM0/x were treated with neoadjuvant chemotherapy followed by resection in two academic centres. Patient data were documented in a prospective database and retrospectively analysed. RESULTS Of all factors prognostic on univariate analysis, only clinical response, complications, ypTNM stage, and R category were independently prognostic (P<0.01) on multivariate analysis. Tumour localisation and signet ring cells were independently prognostic only when investigator-dependent clinical response evaluation was excluded from the multivariate model. Histopathological tumour regression correlates with tumour grading, Laurén classification, clinical response, ypT, ypN, and R categories but was not identified as an independent prognostic factor. Within R0-resected patients only surgical complications and ypTNM stage were independent prognostic factors. CONCLUSIONS Only established prognostic factors like ypTNM stage, R category, and complications were identified as independent prognostic factors in resected patients after neoadjuvant chemotherapy. In contrast, histopathological tumour regression was not found as an independent prognostic marker.

Dermatopathology in sub-Saharan Africa: a systematic 5-year analysis of all histopathological diagnoses from the Regional Dermatology Training Centre (RDTC) in Moshi, Tanzania.

BACKGROUND Proper diagnosis of skin diseases relies on dermatopathology, the most important diagnostic technique in dermatology. Unfortunately, there are few dermatopathology institutions in sub-Saharan Africa, where little is known about the spectrum of histopathological features observed. OBJECTIVES To investigate the spectrum of dermatopathological diagnoses made in a sub-Saharan African reference centre of a large, mainly rural area. PATIENTS/METHODS To retrospectively evaluate all dermatopathological diagnoses made over a period of 5 years at the Regional Dermatology Training Centre (RDTC) in Moshi, Tanzania. RESULTS There were a total of 1554 skin biopsy specimens. In 45% of cases, there were inflammatory diseases, most frequently lichenoid conditions. Cutaneous neoplasms represented 30.4% of all diagnoses, with Kaposi's sarcoma (KS) and, less frequently, squamous cell carcinoma (SCC) being the two most common neoplastic conditions. The latter also reflected the intensive management of persons with albinism in the RDTC. The distribution of histological diagnoses seemed to correlate with the overall clinical spectrum of cutaneous diseases managed in the RDTC. CONCLUSIONS In this African study inflammatory conditions are the main burden of skin diseases leading to a diagnostic biopsy. Our findings provide further evidence that KS, primarily related to the high prevalence of HIV infection is an epidemiological problem. Both SCC and basal cell carcinoma represent another relatively common malignant cutaneous neoplasms, reflecting the presence of specific populations at risk. The challenging spectrum of histological diagnoses observed in this specific African setting with basic working conditions shows that development of laboratory services of good standards and specific training in dermatopathology are urgently needed.

Molecular Classification of Ependymal Tumors across All CNS Compartments, Histopathological Grades, and Age Groups

Ependymal tumors across age groups are currently classified and graded solely by histopathology. It is, however, commonly accepted that this classification scheme has limited clinical utility based on its lack of reproducibility in predicting patients' outcome. We aimed at establishing a uniform molecular classification using DNA methylation profiling. Nine molecular subgroups were identified in a large cohort of 500 tumors, 3 in each anatomical compartment of the CNS, spine, posterior fossa, supratentorial. Two supratentorial subgroups are characterized by prototypic fusion genes involving RELA and YAP1, respectively. Regarding clinical associations, the molecular classification proposed herein outperforms the current histopathological classification and thus might serve as a basis for the next World Health Organization classification of CNS tumors.

Very Late Scaffold Thrombosis: Intracoronary Imaging and Histopathological and Spectroscopic Findings.

BACKGROUND Bioresorbable scaffolds provide transient lumen support followed by complete resorption. OBJECTIVES This study examined whether very late scaffold thrombosis (VLScT) occurs when resorption is presumed to be nearly complete. METHODS Patients with VLScT at 3 tertiary care centers underwent thrombus aspiration followed by optical coherence tomography (OCT). Thrombus aspirates were analyzed by histopathological and spectroscopic examination. RESULTS Between March 2014 and February 2015, 4 patients presented with VLScT at 44 (case 1), 19 (cases 2 and 4), and 21 (case 3) months, respectively, after implantation of an Absorb Bioresorbable Vascular Scaffold 1.1 (Abbott Laboratories, Abbott Park, Illinois). At the time of VLScT, all patients were taking low-dose aspirin, and 2 patients were also taking prasugrel. OCT showed malapposed scaffold struts surrounded by thrombus in 7.1%, 9.0%, and 8.9% of struts in cases 1, 2, and 4, respectively. Scaffold discontinuity with struts in the lumen center was the cause of malapposition in cases 2 and 4. Uncovered scaffold struts with superimposed thrombus were the predominant findings in case 3. OCT percent area stenosis at the time of VLScT was high in case 1 (74.8%) and case 2 (70.9%) without evidence of excessive neointimal hyperplasia. Spectroscopic thrombus aspirate analysis showed persistence of intracoronary polymer fragments in case 1. CONCLUSIONS VLScT may occur at advanced stages of scaffold resorption. Potential mechanisms specific for VLScT include scaffold discontinuity and restenosis during the resorption process, which appear delayed in humans; these findings suggest an extended period of vulnerability for thrombotic events.

Behavioural and histopathological alterations in mice with cerebral malaria.

Different features of sensorimotor function and behaviour were studied in murine cerebral malaria (CM) and malaria without cerebral involvement (non-CM) applying the primary screen of the SHIRPA protocol. Histopathological analysis of distinct brain regions was performed and the relative size of haemorrhages and plugging of blood cells to brain vasculature was analysed. Animals suffering from CM develop a wide range of behavioural and functional alterations in the progressive course of the disease with a statistically significant impairment in all functional categories assessed 36 h prior to death when compared with control animals. Early functional indicators of cerebral phenotype are impairments in reflex and sensory system and in neuropsychiatric state. Deterioration in function is paralleled by the degree of histopathological changes with a statistically significant correlation between the SHIRPA score of CM animals and the mean size of brain haemorrhage. Furthermore, image analysis yielded that the relative area of the brain lesions was significantly larger in the forebrain and brainstem compared with the other regions of interest. Our results indicate that assessment of sensory and motor tasks by the SHIRPA primary screen is appropriate for the early in vivo discrimination of cerebral involvement in experimental murine malaria. Our findings also suggest a correlation between the degree of functional impairment and the size of the brain lesions as indicated by parenchymal haemorrhage. Applying the SHIRPA protocol in the functional characterization of animals suffering from CM might prove useful in the preclinical assessment of new antimalarial and potential neuroprotective therapies.