Elsevier

Human Pathology

Volume 39, Issue 4, April 2008, Pages 514-526
Human Pathology

Original contribution
Aortitis and ascending aortic aneurysm: description of 52 cases and proposal of a histologic classification

https://doi.org/10.1016/j.humpath.2007.08.018Get rights and content

Summary

Noninfectious aortitis typically involves the ascending aorta and causes aneurysms that result in aortic root repair. Aortitis is clinically categorized into groups that include Takayasu disease, giant cell aortitis, and isolated aortitis. We present a histopathologic classification of 52 patients with aortitis, without reference to clinical findings, which are often unknown to the diagnostic pathologist. The largest group (43 patients) was designated necrotizing aortitis (NA), characterized by zonal medial laminar necrosis, rimmed by giant cells. Healed areas were common and were characterized by extracellular accumulation of proteoglycans imparting the appearance of medial degeneration. NA had a bimodal age distribution with a separation at age 65 (adult NA versus elderly NA). Adult NA (24 patients; 50% female; age range, 24-60) was generally isolated, but 2 patients had associated autoimmune disease (Crohn disease and lupus erythematosus, respectively). Elderly NA (19 patients; 94% female; age range, 68-80) was likewise usually isolated, but 1 patient had temporal giant cell arteritis and 1 seronegative arthritis. Subsequent complete rheumatologic workup on 17 patients with NA was negative. Adult NA differed significantly from elderly NA (fewer women, P = .002; greater adventitial scarring, P = .007). The second group of aortitis was designated non-NA (NNA), characterized by the absence of necrosis, with diffuse medial inflammation. The NNA group was composed of 3 men and 6 women, all older than 65 years (mean, 72 ± 6 years). Four had a history of temporal arteritis. NNA patients differed from elderly NA (more frequent temporal arteritis, P = .03; less medial destruction and proteoglycan deposits, P < .01; increased medial T-lymphocytes, P = .05; and more frequent dissection, P = .002). We conclude that NA is usually isolated, has distinct histologic features based on age less than or more than 65 years, and is clinicopathologically distinct from NNA. NNA is less often isolated and best classified as giant cell aortitis. Adult NA has histologic features classically associated with Takayasu disease but is limited primarily to the ascending aorta and has no sex predominance.

Introduction

Noninfectious aortitis is a heterogeneous group of diseases. There is a predilection for the proximal aorta and formation of aneurysms. Noninfectious aortitis is typically classified as Takayasu disease or giant cell aortitis, largely dependent on patient age and other nonspecific clinical criteria [1]. It has been stated, based on relatively few cases, that histologic features of Takayasu disease and giant cell aortitis are sufficiently similar that histologic criteria cannot separate the two. Because many patients with noninfectious aortitis are young and have no extra-aortic manifestations of Takayasu disease, a variety of synonymous overlapping terms have been used, including nonspecific aorto-arteritis and granulomatous aortitis [2], [3], [4]. The most recent series proposes a classification of aortitis that relies entirely on clinical features [5], [6].

The purpose of the current study is to retrospectively analyze a series of aortitis, with an attempt at histologic classification that will enable the surgical pathologist to provide a descriptive diagnosis that will aid in the eventual clinical subclassification of the patient's rheumatologic disease. The use of a 50-year cutoff point was analyzed by histogram, and the presence of medial zonal necrosis is a starting point for histologic subclassification, adding other histologic and immunohistochemical findings.

Section snippets

Case selection

A retrospective search for aortitis was performed at 3 institutions, and cases were retrieved from 1989 to 2005. Fifty-seven cases were initially retrieved. Inclusion criteria were diagnoses with the term “aortitis,” with histopathologic verification of the sections demonstrating primary noninfectious aortitis and excluding mycotic aneurysm, syphilitic aortitis, and inflammation secondary to atherosclerosis or organizing dissection. Five aortitis with predominant adventitial fibrosis and

Results

Based on light microscopic features, cases of aortitis were separated into NA and NNA. There were 43 patients with NA; these patients were separated into 2 groups: those older than 65 years and those younger than 65 years. There were 24 patients younger than 65 years and 18 patients older than 65 years (elderly NA). There was no sex predilection for adult NA; however, women predominated in the group older than 65 years (P = .003 versus adult NA) (Table 1). There was a higher proportion of

Discussion

The current study shows a spectrum of pathologic stages in aortitis that include necrosis, inflammation, regenerative changes, and fibrosis. However, 2 basic types emerge: NNA, which does not result in medial laminar necrosis or elastic loss, and NA. NNA has several features that immediately separate it from NA: exclusive occurrence in the elderly, higher association with giant cell arteritis, a higher rate of dissection, and several histologic features. Significant intimal and adventitial

References (28)

  • I. Yamada et al.

    Pulmonary artery disease in Takayasu's arteritis: angiographic findings

    AJR Am J Roentgenol

    (1992)
  • M. Hotchi

    Pathological studies on Takayasu arteritis

    Heart Vessels Suppl

    (1992)
  • O. Matsubara et al.

    Pathological features of the pulmonary artery in Takayasu arteritis

    Heart Vessels Suppl

    (1992)
  • H.A. Heggtveit

    Syphilitic aortitis. A clinicopathologic autopsy study of 100 cases, 1950-1960

    Circulation

    (1964)
  • Cited by (65)

    • Long-Term Outcome and Prognosis of Noninfectious Thoracic Aortitis

      2023, Journal of the American College of Cardiology
    • Comparison of the damage to aorta wall in aortitis versus noninflammatory degenerative aortic diseases

      2021, Cardiovascular Pathology
      Citation Excerpt :

      The latter discussion emphasizes difficulties in the histological diagnosis of aortitis in cases with tiny or patchy inflammation and prominent degenerative changes. From our analysis of the correlation between inflammatory activity and degenerative changes, it is remarkable that mucoid changes (MEMA-T and MEMA-I) are associated with lower inflammation scores which can be considered as the healing phase in the inflammatory injury [13]. This terminal stage of inflammatory injury results in a pattern (proteoglycan accumulation) which is lacking pathophysiologic specificity.

    View all citing articles on Scopus
    View full text