Abstract: SA-PO853

The Specificity of Histologic Findings in Calciphylaxis

Session Information

  • Vascular Calcification
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Mineral Disease

  • 1205 Vascular Calcification

Author

  • O'Neill, W. Charles, Emory University, Atlanta, Georgia, United States
Background

The diagnosis of calciphylaxis, also known as calcific uremic arteriolopathy (CUA), usually depends on a skin biopsy but data on the specificity of histopathologic criteria are limited. To assess this, histolology was compared in skin biopsies performed for a suspicion of CUA and in skin obtained from healthy margins of amputations in ESRD patients without CUA.

Methods

Skin biopsies in 38 patients with a clinical suspicion of CUA and 43 amputations from ESRD patients without CUA were identified retrospectively. Patients with skin biopsies were assigned a low (16), moderate (6), or high (16) suspicion for CUA based on review of the medical record by a nephrologist unaware of the biopsy results. This determination was based largely on the impression of the consulting dermatologist. Hematoxylin and eosin and von Kossa stains were examined for medial calcification, intimal hyperplasia, or thrombosis of small arteries or arterioles, and for extravascular soft tissue calcification by a pathologist unaware of the clinical information.

Results

Lesions in small arteries or arterioles were present in 35% of amputation specimens and 55% of skin biopsies, but in 87% of skin biopsies from patients with a high suspicion of CUA. Comparison of amputations and high-suspicion skin biopsies is shown in the table. The combination of vessel calcification and thrombosis showed the greatest difference, being 6-fold more prevalent in high-suspicion skin biopsies. The combination of vessel calcification and intimal hyperplasia was not seen in any specimen. There were no significant differences between the findings in amputations and those in the skin biopsies from patients without a high clinical suspicion for CUA.

Conclusion

Histopathologic findings historically associated with calciphylaxis also occur in viable tissue from unaffected ESRD patients. This calls into question the specificity of individual histologic findings for calciphylaxis. However, the combination of vessel calcification and thrombosis may provide more specificity.

 Skin biopsies (%)Amputations (%)p
Vessel calcification63210.004
Thrombosis47140.013
Intimal hyperplasia1312 
Calcif + thrombosis3150.013
Calcif + intimal hyperplasia00 
Non-vasc calcif1940 
Vessel + non-vasc calcif139 

Funding

  • Clinical Revenue Support