Atypical finding of intra- and retroperitoneal haemangiomata

The patient was referred to the urology clinic with a two-week history of haematuria. CT IVU revealed incidental abdominal lesions resembling soft tissue masses associated with the liver, left hemidiaphragm and left iliopsoas muscle.

CT IVU (and subsequent CT abdomen) showed arterially enhancing soft tissue lesions; one 2.3 cm lesion adjacent to the posterosuperior aspect of the left iliopsoas muscle and another 4.5 cm lesion adjacent to the left hemidiaphragm. A thickened gastric diverticulum was seen in the posterior fundus with an associated 12 mm left gastric lymph node.

There were also multiple hypodense lesions in both liver lobes; MRI showed four T2 hyperintense liver lesions in segments II, IVb, V/VIII and VII (largest lesion 1.5 cm) which all demonstrated arterial enhancement. The lesions within segment V and VII demonstrated classical complete centripetal filling in, whilst the smaller lesions did not demonstrate complete fill-in on delayed phase post-contrast sequences.

Background: Haemangiomata are non-epithelial vascular tumours that most commonly arise in childhood. While often found in the liver (prevalence being as high as 20% of the general population [1]), they rarely involve retroperitoneal organs, largely originating from the kidneys when they do [2]. Here we present an interesting case; the occurrence of retroperitoneal and intraperitoneal haemangiomata together is unusual, and finding them in combination with hepatic haemangiomata is rarer still, raising the possibility of a haemangiomatosis syndrome (though there were no overt features of known conditions such as Klippel-Trenaunay, Proteus or blue rubber bleb naevus syndromes [3])

Clinical and imaging perspectives: Haemangiomata generally remain asymptomatic unless they grow large enough to compress surrounding structures and/or rupture [2, 4], or increase in size rapidly to cause systemic haematological disturbance (consumptive coagulopathy) in the form of the rarely seen Kasabach-Merritt syndrome [5].  Retro- and intraperitoneal haemangiomata can be difficult to diagnose; not only can they appear in atypical locations with unusual features, they can also mimic soft tissue malignancies such as liposarcoma, neuroendocrine tumour or metastatic peritoneal deposits.

This was particularly relevant in this case given the thickened stomach wall seen on CT. Oesophagogastroduodenoscopy (OGD), however, found no abnormalities in the upper gastrointestinal tract consistent with malignancy, and on CT imaging the lungs were unremarkable. The histology from the iliopsoas mass, obtained via CT-guided biopsy, showed dilated vascular channels with no cytological atypia. Immunohistochemistry showed positive staining for CD31 and negative staining for D2-40 and calretinin. These findings, together with the classical enhancement characteristics of all the lesions (peripheral nodular enhancement and central in-filling), suggest with a very high degree of a certainty that hepatic lesions are benign liver haemangiomata.

Outcome: The patient remained asymptomatic and multidisciplinary team discussion outcome was to perform CT imaging in 3-6 months to assess stability/interval growth.

Take Home Message, Teaching Points:

• Haemangiomata are a common incidental finding; though most common in the intraperitoneal compartment, they can also be found in the retroperitoneum.
• Haemangiomas can appear as soft tissue masses. Imaging and biopsy is needed to differentiate the two and characterise malignant potential.

Verbal informed patient consent for publication has been obtained.