Hepatic sclerosing cavernous haemangioma can mimic the nodular elastosis stage of segmental atrophy

Aims: Segmental atrophy (SA) of the liver is a recently described pseudotumour that can show a broad spectrum of histological changes. The previously described histological differential diagnosis of SA has included cystic disease of the liver, amyloid, cancer-associated elastosis, and epithelioid haemangioendothelioma. We have observed that sclerosing cavernous haemangiomas (SCHs) can mimic the nodular elastosis stage of SA; the aim of this study was to explore this differential diagnosis. Methods and results: We identified 20 SCHs and 12 SAs, excluding haemangiomas with treatment effect. Several clinical and morphologic characteristics were examined, and elastin and CD34 staining was performed on cases with available tissue. SA was always asymptomatic, whereas SCH caused symptoms in 56% of patients (P = 0.026); SCH also tended to be larger (mean size: SCH, 47 mm; SA, 16 mm; P = 0.027). Thick-walled blood vessels were more common in SA than in SCH (92% versus 45%, P = 0.011), as was ductular reaction (50% versus 5%, P = 0.0057). The two lesions had similar rates of border irregularity, residual entrapped hepatocytes, matrix oedema, and at least mild elastic fibrosis as seen on special staining, although staining was typically dense and diffuse in SA. CD34 immunostaining demonstrated at least scattered vessels in all cases of SA and SCH. Conclusions: SCH can mimic SA, although it is generally larger and more often symptomatic. Elastin staining provides a useful adjunct to standard haematoxylin and eosin histological examination in resolving this differential diagnosis.