A Clinicoimmunohistopathologic Study of Anetoderma: Is Protruding Type More Advanced in Stage Than Indented Type?

Abstract

Background. The clinical and histopathologic classification of anetoderma are not well characterized. Objective. We aimed to investigate the clinical and histopathologic characteristics of anetoderma and to correlate clinical phenotypes with immunohistopathologic findings. Methods. We retrospectively reviewed the medical records of 30 patients with anetoderma and performed immunohistochemistry for elastin, fibrillin-1, metalloproteinase- (MMP-) 2, MMP-7, MMP-9, and MMP-12, and tissue inhibitor of metalloproteinase- (TIMP-) 1 and TIMP-2. Results. Protruding type (n = 17) had a longer disease duration and more severe loss of elastin, without changes in fibrillin, than indented type (n = 13). MMP-2 and MMP-9 showed significantly higher expressions in the dermis compared with controls (p < 0.05). MMP-7 and MMP-12 showed little expressions in both anetoderma and control tissue. TIMP-1 was highly expressed in anetoderma lesions and controls. TIMP-2 expression was variable. Conclusions. Our findings suggest that protruding type anetoderma may represent a more advanced stage and that MMP-2 and MMP-9 could be responsible for elastic fiber degradation in anetoderma.

Figure 1

(a) Clinical photo of protruding anetoderma lesions, (b) indented anetoderma lesions, (c) protruding anetoderma lesions of another patient, and (d) indented anetoderma lesions simultaneously found in the same patients who had the protruding lesions shown in (c).

Figure 2

The degree of destruction of elastic fibers was greater in the protruding type than the indented type. (a) Protruding anetoderma lesions; (b) indented anetoderma lesions (elastin, original magnification: ×100).

Figure 3

(a) Most MMP-9-expressing spindle shape cells in the dermis showed immunopositivity for (b) CD-68 or (c) CD45 (magnification: ×100).

Figure 4

Immunohistochemical study results for elastogenesis and degradation markers in protruding and indented type anetoderma (cases 1 and 2: protruding anetoderma lesions, case 3: indented anetoderma lesion, and control 1: control of case 1) (magnification: ×100).

Figure 5

The mean optical density for elastogenesis and degradation markers in the dermis of protruding and indented type anetoderma. (a) Elastin, (b) fibrillin, (c) MMP-2, (d) MMP-9, and (e) TIMP-1 (P1: protruding lesion from case 1, C1: nonlesional control from case 1, P2: protruding lesion from case 2, C2: nonlesional control from case 2, I: indented lesion from case 3, C: nonlesional control from case 3, and N: control from normal patient) ^∗p < 0.05: t-test, between two groups.