Skin nontumor
Dermal collagen and elastic tissue alterations and metabolic disorders
Pseudoxanthoma elasticum
Last author update: 1 August 2011
Last staff update: 5 August 2020
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PubMed Search: Pseudoxanthoma elasticum [title]
Table of Contents
Definition / general | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Electron microscopy description | Differential diagnosis | Additional referencesCite this page: Hamodat M. Pseudoxanthoma elasticum. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorpseudoxanthoma.html. Accessed December 4th, 2024.
Definition / general
- Genetic disorder with ocular, vascular and skin lesions due to mutations of ABCC / MRP6 gene at 16p13.1, coding for ATP binding protein, and causing degeneration of elastic fibers
- Variable penetrance, even within the same family
- Autosomal dominant or recessive, usually women
- Skin: yellow streaks and plaques, particularly in creases of axillae, groin and neck; appear before puberty
- Eyes: angioid streaks in retina, causing hemorrhage and visual loss
- Vessels: degenerative changes in arteries causing mineralization, occlusion or rupture
Case reports
- 26 year old with sudden death while dancing, due to intramyocardial arteriolar involvement (Hum Pathol 2000;31:1002)
- 32 year old man with multiply, yellowish, waxy papules on neck (Case #332)
- 51 year old man with plaques on arm (Dermatol Online J 2001;7:16)
Microscopic (histologic) description
- Affected elastic fibers are basophilic and irregular, appearing as widely dispersed granular material amidst normal collagen fibers; may have a bizarre appearance reminiscent of a bishop's crook
- Abnormal fibers are bright pink with an altered architecture, as they have lost their normal interlacing pattern but may be faintly basophilic due to calcium
- Increased dermal mucin may be evident
- Vascular involvement consists of fragmentation of the internal and external elastic laminae, accompanied by intimal thickening, resulting in weakness of the vessel wall and a tendency towards rupture and aneurysm formation
- Eye: calcifications of Bruch’s membrane, which separates the choroid from the pigment epithelium of the retina
Microscopic (histologic) images
Case #332
Verhoeff Van Gieson stain for elastic fibers
Positive stains
- Verhoeff Van Gieson stain for elastic fibers shows marked degeneration of fibers with a short and curled appearance
- Von Kossa stain reveals calcium deposition
- Fibers also stain positive with Alizarin red calcium stain
Electron microscopy description
- Fragmented and polymorphic elastic fibers in reticular dermis
- Fibers may contain finely disbursed, mineral crystals
- Similar changes in carriers
Differential diagnosis
- Cutis laxa: loss of elastic tissue in the papillary and reticular dermis; fibers are shortened, tapered and degenerate (Arch Dermatol 1965;92:373)
- Late onset focal dermal elastosis: normal elastic fibers in the mid and deep dermis, with no evidence of calcification (Am J Dermatopathol 1999;21:381)
- Manifestations of pseudoxanthoma elasticum, including cutaneous lesions, angioid streaks and vascular calcification, have been identified in many hemolytic conditions including beta thalassemia, sickle cell disease and hereditary spherocytosis (Br J Haematol 2003;122:852)
- Penicillamine therapy: similar skin lesions but also produces elastosis perforans, serpingiosa and collagen defects
- Pseudoxanthoma elasticum-like papillary dermal elastolysis occurs in elderly females, systemic lesions are absent; partial or complete elastolysis in the papillary dermis but calcification is typically absent with normal collagen fibers (Br J Dermatol 1998;139:141)
- Saltpeter: similar dermal changes histologically and ultrastructurally
Additional references
