Abdominal elastotic lesions. A clinicopathologic study of 23 cases

Abstract

Abdominal elastotic deposits are uncommon lesions that often presents as polyps. They show three histological patterns: fibroelastosis, angioelastosis, and elastofibroma. We describe 23 cases including rare locations, such as mesentery, greater omentum, hernia sac, spleen, peripancreatic fat, and hypodermal fat. The age of the patients ranged from 49 to 93 years (mean, 76.8 years). Most lesions were discovered incidentally in the microscopic study. The most frequent locations were peritoneal subserosa (43.5%) and mesentery∕mesocolon∕greater omentum (39.1%). The most common pattern was fibroelastosis (69.6%) followed by angioelastosis (26.1%). We observed one case of omental elastofibroma. A review of the 14 abdominal elastofibromas described including our case revealed that the age of the patients ranged from 45 to 88 years (mean, 68.5 years). Female predominance is striking (M:F, 1:12). The most common site was the stomach (50%). The greater omentum (14.3%), small intestine (7.1%), and pancreas (7.1%) are very rare sites for this lesion. Only one case before ours has been published in the greater omentum. The size of the lesions ranged from 0.7 cm to 8 cm (mean 3.2 cm). In 36.4% of the cases located in the digestive tract, the mucosa did not show alterations. Ulcerations (36.4%) or polypoid excrescences (18.2%) were mostly observed. Six (42.9%) cases were asymptomatic and six (42.9%) cases simulated a neoplasm. Two cases were associated with elastofibromas in other locations. Differential diagnosis includes amyloidoma, elastofibrolipoma, mesenteric elastic vascular sclerosis in neuroendocrine tumors, diverticular disease elastosis, pseudoxanthoma elasticum, pulse granuloma, and digestive lesions in patients treated with D-Penicillamine.

Figure 1

Fibroelastosis: (A) Finely granular, pale, eosinophilic material with fibrous component. (B) Wiry fibrillar material with pseudomyxoid change. There is accompanying fibrous tissue. Hematoxylin–Eosin (HE) staining: (A and B) ×200

Figure 2

Fibroelastosis: (A) Mixed flocculent, finely granular, and fibrillar deposit; (B) The elastic fibers that comprise the lesion are revealed with an elastic staining. Hematoxylin–Eosin (HE) staining: (A) ×200. Verhoeff’s elastic procedure (VEP): (B) ×100

Figure 3

Fibroelastosis: (A) Purely granular eosinophilic deposit in mesocolon; (B) Grayish, amphophilic, granular deposit in hernia sac; (C) The elastic special staining highlights the elastic fibers in the hernia sac; (D) Linear granular deposits in a case of fibrous peritonitis. Hematoxylin–Eosin (HE) staining: (A and D) ×200; (B) ×100. Verhoeff’s elastic procedure (VEP): (C) ×100

Figure 4

Angioelastosis: (A) Mesentery: the finely granular eosinophilic material causes thickening of the vascular wall with lumen stenosis; the vessels are surrounded by a mantle of untruncated elastic fibers with obliteration of the lumens; (B) Mesocolon; (C) Colon polyp; (D) Spleen. Hematoxylin–Eosin (HE) staining: (A) ×200. Verhoeff’s elastic procedure (VEP): (B–D) ×100

Figure 5

Elastofibroma: (A) Lesion showing paucicellular collagen bundles and coarse truncated wavy elastic fibers; (B) Elastic fibers showed prominent eosinophilia and serrated outlines; (C) Skipped lesion – presence of globules and a perivascular elastofibromatous lesion; (D) VEP confirmed the presence of fragmented fibers with serrated edges, and globules. Hematoxylin–Eosin (HE) staining: (A) ×200; (B and C) ×400. Verhoeff’s elastic procedure (VEP): (D) ×200

Figure 6

Cellular immunohistochemistry. All lesions showed in varying amount a mixture of CD34 (A, ×400), Factor XIIIa (B, ×400), calponin (C, ×400), and α-SMA (D, ×200) positive cells. These cells were spindle- or stellated-shaped and were often predominant at the periphery of the elastotic deposits. CD34: Cluster of differentiation 34; α-SMA: Alpha-smooth muscle actin