Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases

Inflammatory diseases of the aorta include routine atherosclerosis, aortitis, periaortitis, and atherosclerosis with excessive inflammatory responses, such as inflammatory atherosclerotic aneurysms. The nomenclature and histologic features of these disorders are reviewed and discussed. In addition, diagnostic criteria are provided to distinguish between these disorders in surgical pathology specimens. An initial classification scheme is provided for aortitis and periaortitis based on the pattern of the inflammatory infiltrate: granulomatous/giant cell pattern, lymphoplasmacytic pattern, mixed inflammatory pattern, and the suppurative pattern. These inflammatory patterns are discussed in relation to specific systemic diseases including giant cell arteritis, Takayasu arteritis, granulomatosis with polyangiitis (Wegener's), rheumatoid arthritis, sarcoidosis, ankylosing spondylitis, Cogan syndrome, Behçet's disease, relapsing polychondritis, syphilitic aortitis, and bacterial and fungal infections.

An update of the Mayo Clinic cohort of patients with adult primary central nervous system vasculitis: description of 163 patients

Primary central nervous system vasculitis (PCNSV) is an uncommon condition in which lesions are limited to vessels of the brain and spinal cord. Because the clinical manifestations are not specific, the diagnosis is often difficult, and permanent disability and death are frequent outcomes. This study is based on a cohort of 163 consecutive patients with PCNSV who were examined at the Mayo Clinic over a 29-year period from 1983 to 2011. The aim of the study was to define the characteristics of these patients, which represents the largest series in adults reported to date. A total of 105 patients were diagnosed by angiographic findings and 58 by biopsy results. The patients diagnosed by biopsy more frequently had at presentation cognitive dysfunction, greater cerebrospinal fluid total protein concentrations, less frequent cerebral infarcts, and more frequent leptomeningeal gadolinium-enhanced lesions on magnetic resonance imaging (MRI), along with less mortality and disability at last follow-up. The patients diagnosed by angiograms more frequently had at presentation hemiparesis or a persistent neurologic deficit or stroke, more frequent infarcts on MRI and an increased mortality. These differences were mainly related to the different size of the vessels involved in the 2 groups. Although most patients responded to therapy with glucocorticoids alone or in conjunction with cyclophosphamide and tended to improve during the follow-up period, an overall increased mortality rate was observed. Relapses occurred in one-quarter of the patients and were less frequent in patients treated with prednisone and cyclophosphamide compared with those treated with prednisone alone. The mortality rate and degree of disability at last follow-up were greater in those with increasing age, cerebral infarctions on MRI, angiographic large vessel involvement, and diagnosis made by angiography alone, but were lower in those with gadolinium-enhanced lesions on MRI and in those with cerebral amyloid angiopathy. The annual incidence rate of PCNSV was estimated at 2.4 cases per 1,000,000 person-years. PCNSV appears to consist of several subsets defined by the size of the vessels involved, the clinical characteristics at presentation, MRI findings, and histopathological patterns on biopsy. Early recognition and treatment may reduce poor outcomes.

Comparing velour versus silicone interfaces at the driveline exit site of HeartMate II devices: infection rates, histopathology, and ultrastructural aspects

BACKGROUND

Driveline exit site (DLES) infection is a major complication of ventricular assist devices (VADs). Differences in the sheath material interfacing with exit site tissue appear to affect healing time and infection risk more than site hygiene, but the mechanistic basis for this is not clear.

METHODS

Health record data from Utah Artificial Heart Program patients with HeartMate II (HMII) devices implanted from 2008 to 2012 were retrospectively reviewed, with particular attention to interface type, incorporation (healing) time, and infections. Tissue samples from the DLES were collected at the time of VAD removal in a small subset. These samples were examined by routine histology and environmental scanning electron microscopy (ESEM).

RESULTS

Among 57 patients with sufficient data, 15 had velour interfaces and 42 had silicone. Indications for and duration of support were similar between the groups. The silicone group had shorter incorporation time (45 ±22 vs. 56 ±34 days, P=.17) and fewer DLES infections (20% vs. 1.7%, P=.026, for patient infections and 0.0340 vs. 0.166, P=.16, for infections per patient-year). Tissues from five patients, three with velour, were examined. Velour interfaces demonstrated more hyperkeratosis, hypergranulosis, and dermal inflammation. By ESEM, the silicone driveline tracts appeared relatively smooth and flat, whereas the velour interface samples were irregular with deep fissures and globular material adhering to the surface.

CONCLUSIONS

Using the silicone portion of the HMII driveline at the DLES was associated with fewer infections and a trend toward faster healing in this small retrospective series. Whether the intriguing microscopic differences directly account for this needs further study on a larger scale.

Abstract P3-05-03: HER2-CONNECT® pathologist-assisted image analysis algorithm for HER2 IHC interpretation improves correlation with HER2 FISH results

Background: HER2 testing by immunohistochemistry (IHC) is prone to inter-observer variability and subjective interpretation. Pathologist-assisted digital image analysis is recommended in the CAP/ASCO guidelines to improve interpretive consistency. As a quality benchmark, HER2 IHC results should correlate with HER2 fluorescence in-situ hybridization (FISH) in >95% of positive and negative cases. HER2-CONNECT® (Visiopharm, Hoersholm Denmark) is a digital analysis algorithm that scores stained membrane interconnectivity rather than relying solely on staining of individual cells. As such, it can be thought of as a surrogate for the so-called “chickenwire” pattern characteristic of true HER2 positive tumors. In this study we applied HER2-CONNECT® analysis with pathologist quantitative interpretation (HC+PQI) to a set of breast tumors with known HER2 FISH status to assess concordance.

Design: Breast carcinoma tissue sections previously stained with HER2 IHC (HercepTest) and interpreted manually were retrospectively re-submitted for HC+PQI. These included core and excisional biopsies from primary and metastatic sites. Fixation times were documented within recommended guidelines. HER2 FISH (PathVysion) was performed on all cases. Using connectivity scores on a scale of 0 - 1.0 from the analyzed regions, a pathologist determined the overall% of HER2 positive tumor cells in the sample (since HER2-CONNECT reports connectivity, but not tumor cell quantitation) and reported a final score per CAP/ASCO guidelines (<10% = 1+, 10-30% = 2+, >30% = 3+).

Results: 190 cases comprised the analysis set, including 77 3+, 73 2+, and 40 0/1+ as scored in the original reports. 66 cases were HER2 FISH amplified (64/77, 83% of the original 3+ cases and 2/73, 2.7% of 2+ cases) and 6 cases were FISH equivocal. None of the 0/1+ cases were HER2 FISH amplified. Using HC+PQI, the new scores were 67 3+, 68 2+, and 55 1+. Correlation between HC+PQI and HER2 FISH was 95.5% (64/67) for 3+/amplified and 100% (55/55) for <2+/nonamplified (overall concordance 97.5%). Using FISH as the gold standard, the HC+PQI interpretation reduced the false positive rate from 13% (15/108) to 3% (4/108). 17 of 63 HER2 nonamplified samples originally scored 2+ were changed to 1+ on HC+PQI (i.e. reduction of FISH testing by 27% (17/63)).

Conclusions: Relative to the original report scores, HC+PQI improved correlation with HER2 FISH and reduced the overall number of 2+ results (potentially reducing the number of FISH tests required). These data also objectively highlight the importance of the “chickenwire” pattern in positive result interpretation for HER2.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-05-03.

Surgical pathology of atrial appendages removed during the cox-maze procedure: a review of 86 cases (2004 to 2005) with implications for prognosis

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Some patients are managed surgically (Cox-maze procedure) with removal of 1 or both atrial appendages. A retrospective review was performed on surgically excised atrial appendages from 86 consecutive patients with AF (2004 to 2005), at Mayo Clinic in Rochester, MN. These were compared with atrial appendages removed from 2 autopsy control groups without a history of AF (26 without heart disease, and 20 with heart disease). Compared with the 2 control groups, appendages from patients with AF contained more myocyte vacuolization, fatty infiltration, and myocardial inflammation. Among the AF patients, left atrial appendages (LAA) were larger and more likely to show fatty infiltration, endocardial fibroelastosis, and mural thrombus than were right atrial appendages (RAA); in contrast, RAA were more likely to show myocyte hypertrophy and interstitial fibrosis than were LAA. In the LAA, myocyte hypertrophy and interstitial fibrosis were more often seen in patients with long-term AF recurrence than were those who remained in normal sinus rhythm postoperatively (P=0.045 and 0.036, respectively). Given the potential clinical relevance of these findings, it is recommended that the presence or absence of hypertrophy and fibrosis, and their extent, be incorporated into the surgical pathology report of all patients undergoing resection of an atrial appendage.

Effect of ventriculotomy on right-ventricular remodeling in hypoplastic left heart syndrome: a histopathological and echocardiography correlation study

The objective of this study was to compare histopathological changes in hypoplastic left heart syndrome right ventricles (RV) of patients undergoing Sano and modified Blalock-Taussig (MBT) shunt and correlate them with echocardiographic findings. Myocardial tissue samples were obtained from hearts with Sano or MBT shunts after transplantation or at autopsy. Histologic sections were reviewed manually and by automated digital image analysis. Velocity vector imaging was performed on echocardiogram images obtained before transplant or death. All of these parameters were compared between the Sano and MBT shunt cohorts. A total of 14 specimens (7 Sano and 7 MBT shunt) were studied. Median age at transplant/death of Sano and MBT shunt cohorts was 11 (range 2-41) and 8 months (range 2-200), respectively. All Sano specimens had a scar at ventriculotomy site, and the mean scar area was 6.2 ± 3.3 cm(2). Compared with remote RV free wall, myocardium bordering the scar showed increased fibrosis (34 ± 16 % vs. 28 ± 14 %, p = 0.04) and thinning (0.8 ± 0.9 vs. 5.3 ± 0.8 mm; p < 0.001), which did not regress with time. The Sano ventriculotomy site showed significantly decreased velocity, strain, and strain rate compared with the corresponding contralateral segment. No focal scarring or regional hypokinesia was seen in the MBT shunt cohort. This is the first study to demonstrate histopathological features of ventriculotomy-associated RV myocardial scarring and myocardial thinning. The scarred ventriculotomy site showed decreased segmental myocardial deformation after Norwood with Sano shunt.

Metastatic melanoma to the heart

Melanoma is a common neoplasm with a propensity to metastasize to the heart. Although cardiac metastasis is rarely diagnosed ante mortem, using a multimodality approach, several imaging findings may be seen. Echocardiography is often the initial imaging method used to detect cardiac metastases and their complications. On computed tomography, intraluminal filling defects and myocardial/pericardial nodules may be seen. On magnetic resonance imaging, metastatic melanoma is classically hyperintense on T1 images and hypointense on T2 images, a result of the T1 shortening of melanin; however, this is seen in a minority of cases. As melanoma metastases are fluorine-18-fluorodeoxyglucose avid, fluorine-18-fluorodeoxyglucose positron emission tomography may also be used to detect cardiac metastases.

A longitudinal study of the course of asymptomatic antibody-mediated rejection in heart transplantation

BACKGROUND

Growing evidence suggests worse cardiac allograft vasculopathy and mortality in patients with asymptomatic antibody-mediated rejection (AMR). Debate continues about whether therapeutic intervention is warranted to avoid adverse outcomes. In this study we examine the course of individual episodes of untreated asymptomatic AMR on follow-up endomyocardial biopsy (EMB).

METHODS

The U.T.A.H. Cardiac Transplant Program database was queried for transplant recipients between 1985 and 2009 who survived beyond 1 year and had at least 1 episode of lone AMR with a follow-up EMB. All EMBs were screened for AMR by immunofluorescence and graded for severity. Data were analyzed based on time from transplant (early, ≤12 months; late, >12 months).

RESULTS

Nine hundred fifty-eight patients with a total of 15,448 biopsies qualified for the study. Average age at transplant was 46.7 years; 13% of the patients were female. Within the first year post-transplant, asymptomatic AMR was diagnosed in 13.6% of biopsies compared with 5.2% beyond 1 year. AMR resolved in 65% (early) vs 75% (late) on follow-up EMB. More severe AMR was less likely to improve regardless of time from transplant. Furthermore, after an episode of AMR had resolved, the recurrence rate at 3, 6 and 12 months was 44%, 50.1% and 56.2%, respectively.

CONCLUSIONS

The incidence of AMR is higher in the first year post-transplant and the likelihood of resolution is less on follow-up EMB, especially when more severe. A small but significant number of cases became worse or did not change. These new findings may be helpful in planning future studies that test whether therapeutic interventions on asymptomatic AMR favorably impact outcomes.

Cardiac Tumors

Cardiac neoplasms and other mass-forming lesions are not commonly encountered in surgical pathology practice. Fortunately, for the most part, these fall into a small group of well characterized and readily-recognized entities, although they are not without diagnostic dilemmas. A brief and practical synopsis of cardiac tumors is presented in this section with attention to more frequently encountered and clinically significant diagnostic challenges as well as pertinent clinical associations and prognostic information.

Horses and Zebras: complex cardiac anatomy in a patient with out-of-hospital cardiac arrest

This case report describes a woman presenting after out-of-hospital cardiac arrest with several cardiac anomalies, including a form fruste of Ebstein's anomaly complicated by a large tricuspid valve vegetation. On autopsy, she proved to have unstable plaques in epicardial vessels that likely caused arrhythmic sudden cardiac death, a reminder that even in the presence of rare anomalies, common things are common.

The pathology of large-vessel vasculitides

Vasculitis affecting large elastic arteries, including the aorta and major proximal branches, encompasses various diseases including Takayasu arteritis, giant cell (or temporal) arteritis, and tertiary syphilis, but also may occur as a rare complication of Behçet's disease, rheumatoid arthritis, sarcoidosis, Cogan syndrome, Kawasaki disease, ankylosing spondylitis, systemic lupus erythematosus and Wegener's granulomatosis. Recent reports have also established a link between inflammatory abdominal aortic aneurysm as well as lymphoplasmacytic thoracic aortitis with an overabundance of IgG4-producing plasma cells and the burgeoning constellation of 'Hyper-IgG4' syndromes. This review focuses on morphologic aspects of large-vessel vasculitis pathology associated with giant cell arteritis, Takayasu arteritis, idiopathic or isolated aortitis, lymphoplasmacytic thoracic and ascending aortitis, and the inflammatory aneurysm/retroperitoneal fibrosis syndrome.

Vasculitis of the gastrointestinal tract in chronic periaortitis

The term "chronic periaortitis" (CP), proposed by Mitchinson in 1984, comprises 3 main entities: idiopathic retroperitoneal fibrosis (IRF), inflammatory abdominal aortic aneurysms (IAAAs), and perianeurysmal retroperitoneal fibrosis (PRF).The presence of constitutional symptoms, high acute-phase reactants, positive autoantibodies, and associated autoimmune diseases suggests a systemic inflammatory process. Histopathologic findings show vasculitis with fibrinoid necrosis involving the aortic vasa vasorum as well as the small and medium retroperitoneal vessels.We reviewed the medical records of 608 patients with a diagnosis of vasculitis involving the gastrointestinal (GI) tract at the Mayo Clinic between January 1996 and December 2007. Only patients with biopsy-proven or typical angiographic findings of vasculitis localized to the GI tract were included.Five patients were identified with evidence of CP (1 patient with PRF, 1 with IRF, and 3 with IAAAs). Three patients were men, and the median age at diagnosis was 49 years. The diagnosis of GI vasculitis and CP was made simultaneously in 4 patients. At the time of onset, all patients had abdominal pain and constitutional manifestations; the median erythrocyte sedimentation rate was 62.5 mm/1 h (range, 20-86 mm/1 h). All patients had evidence of mesenteric vasculitis at angiography. Three patients also had associated renal artery stenoses. Abdominal computed tomography showed spleen infarcts in 2 patients, bowel wall thickening in 1, and liver infarction in 1. Two patients underwent surgical intervention for acute abdomen; there was histologic evidence of small bowel infarcts and infarction of the spleen and liver in 1. Oral prednisone was administered to all 5 patients (median starting dose, 60 mg/d; range, 25-80 mg/d). Three patients also received immunosuppressive agents, 1 tamoxifen, and 1 anti-tumor necrosis factor therapy. All patients had at least 1 relapse or recurrence of vasculitis, but at last visit, GI vasculitis and CP were in remission in all 5 patients.This study provides evidence that GI manifestations due to mesenteric vasculitis may be associated with CP. Vasculitic involvement of the renal arteries is also frequently present in these patients. Aggressive immunosuppressive treatment should be promptly initiated to forestall abdominal complications. These findings reinforce the hypothesis that a vasculitic process plays an important role in the pathogenesis of CP.

Detection of C4d deposition in cardiac allografts: a comparative study of immunofluorescence and immunoperoxidase methods

CONTEXT

Complement activation, evidenced by deposition of C4d, is important in the diagnosis of antibody-mediated rejection of cardiac allografts. C4d deposition can be assessed by either immunofluorescence (IF)- or immunoperoxidase (IP)-based methods. The use of methods varies considerably among institutions, but there are few data addressing their diagnostic equivalence.

OBJECTIVE

To compare IF and IP C4d staining on paired endomyocardial biopsy samples from a large number of heart transplant patients.

DESIGN

Retrospectively selected paired frozen and paraffin-embedded samples from the same biopsy were stained for C4d by IF and IP methods. Capillary staining was scored by using a 0, 1+, 2+, 3+ scale.

RESULTS

A total of 296 biopsy pairs from 70 patients were studied. There were two hundred forty-three cases that were scored 0, twenty-four scored 1+, sixteen scored 2+, and thirteen scored 3+ by IF. Two hundred thirty-one cases scored 0, forty scored 1+, ten scored 2+, and fifteen scored 3+ by IP. Complete agreement was seen in 81% of cases. Among discrepant cases, 89% (n  =  51) were minor (±1) and 11% (n  =  6) were major (±2). Five of the 6 major discrepancy biopsies came from 2 patients, both of whom had concordant (IF and IP) 3+ results on prior biopsies. The weighted κ value for the entire sample set was 0.78 and for the first biopsy only set (to correct for bias introduced by multiple biopsies from the same patient) the weighted κ value was 0.88.

CONCLUSIONS

Immunofluorescence and IP C4d staining methods are highly comparable and are both viable options for antibody-mediated rejection surveillance in transplant heart biopsies.

Rapidly progressive primary central nervous system vasculitis

OBJECTIVE

To describe a subset of cases in a large cohort of patients with primary CNS vasculitis (PCNSV) who appear to have a rapidly progressive clinical course.

METHOD

In the present study, we use our updated cohort of 131 consecutive patients with PCNSV seen over the 25-year period of 1983-2007 at Mayo Clinic, Rochester, MN, USA. The diagnosis of PCNSV was based on brain/spinal cord biopsy or cerebral angiography. The modified Rankin scale was used to identify rapidly progressive disease and included patients with Rankin scores indicating severe disability or death at diagnosis or within 6 months after the diagnosis. We compared patients with rapidly progressive disease to those without.

RESULTS

Compared with the 120 patients without rapidly progressive vasculitis, the 11 patients with rapidly progressive vasculitis more frequently had paraparesis/quadriparesis at presentation, angiographic presence of bilateral, large-vessel vasculitis and MRI evidence of cerebral infarctions; those infarctions were more frequently multiple and bilateral, and more frequently involved both the cortex and subcortical regions on initial MRI. Granulomatous and/or necrotizing histopathological patterns of vasculitis were observed in patients with positive biopsies.

CONCLUSION

Rapidly progressive PCNSV appears to form a subset of PCNSV at the worst end of the clinical spectrum of this vasculitis, characterized by bilateral, multiple, large cerebral vessel lesions and multiple CNS infarctions.

Dense deposit disease associated with monoclonal gammopathy of undetermined significance

Dense deposit disease (DDD) is a rare glomerular disease that typically affects children, young adults, and much less commonly, older patients. The pathophysiologic process underlying DDD is uncontrolled activation of the alternative pathway (AP) of complement cascade, most frequently secondary to an autoantibody to C3 convertase called C3 nephritic factor, although mutations in factor H and autoantibodies to this protein can impair its function and also cause DDD. Since 1995, we have diagnosed DDD in 14 patients aged 49 years or older; 10 of these patients (71.4%) carry a concomitant diagnosis of monoclonal gammopathy of undetermined significance (MGUS). In 1 of these 10 patients, the index case described here, we evaluated the AP and showed low serum AP protein levels consistent with complement activity, heterozygosity for the H402 allele of factor H, and low levels of factor H autoantibodies, which can affect the ability of factor H to regulate AP activity. In aggregate, these findings suggest that in some adults with MGUS, DDD may develop as a result of autoantibodies to factor H (or other complement proteins) that on a permissive genetic background (the H402 allele of factor H) lead to dysregulation of the AP with subsequent glomerular damage. Thus, DDD in some older patients may be a distinct clinicopathologic entity that represents an uncommon complication of MGUS.