The literature is rich in case reports of intraosseous haemangioma, although most of these are actually cases of venous or capillary malformations. To illustrate this confusion in terminology, we present three cases of slow-flow vascular malformations misnamed as intraosseous haemangioma. A retrospective study of children diagnosed with intraosseous haemangioma was conducted. Clinical and radiological data were evaluated. Histopathological examinations and immunohistochemical studies were redone by three independent pathologists to classify the lesions according to the International Society for the Study of Vascular Anomalies (ISSVA) and World Health Organization (WHO) classifications. Three children who had presented with jaw haemangiomas were identified. Computed tomography scan patterns were not specific. All tumours were GLUT-1-negative and D2-40-negative. The lesions were classified as central haemangiomas according to the WHO, and as slow-flow malformations according to the ISSVA. The classification of vascular anomalies is based on clinical, radiological, and histological differences between vascular tumours and malformations. Based on this classification, the evolution of the lesion can be predicted and adequate treatment applied. The binary ISSVA classification is widely accepted and should be applied for all vascular lesions.
In 1982, Mulliken and Glowacki published a classification for vascular birthmarks, grouping them into two categories: haemangiomas and malformations. Vascular malformation was differentiated from haemangioma by clinical, radiological, and histological features ( Table 1 ).
|Gender distribution||Female > male||Equal|
|Presence at birth||No||Yes|
|Natural history||Rapid proliferation for the first several months of life and spontaneous regression||Growth proportionately with the child. May become more prominent, especially at puberty|
|Histology||Endothelial hyperplasia||Mature vascular elements|
|Large numbers of mast cells||Normal numbers of mast cells|
|Immunohistochemistry||GLUT-1-positive cells||GLUT-1-negative cells|
Haemangioma is a common tumour of infancy, with a female predisposition. This lesion appears in infancy, grows rapidly until the age of 8 months to 1 year, and then slowly involutes by adolescence. According to Boyd et al. and Kaban and Mulliken, haemangiomas do not involve the bone, although they can deform the adjacent bone or create minor osseous overgrowth. Histologically, haemangiomas have endothelial hyperplasia and a large number of mast cells. Moreover, endothelial cells within the infantile haemangioma will stain positive for glucose transporter 1 (GLUT-1).
Vascular malformations are present at birth, and have an equal sex distribution. They grow with the child and may become more prominent, especially at puberty. Histologically, vascular malformations do not show endothelial hyperplasia and demonstrate a normal number of mast cells. They consist of mature vascular elements. Vascular malformations can be subdivided according to their vascular components into slow-flow (capillary, venous, and lymphatic) and fast-flow (arteriovenous) malformations. The classification of Mulliken and Glowacki was adopted widely and became the accepted classification of the International Society for the Study of Vascular Anomalies (ISSVA) in 1996.
Despite this classification, the oral and maxillofacial and orthopaedic literature persists in classifying lesions according to the World Health Organization (WHO). In the WHO classification, haemangioma is defined as “a benign vasoformative neoplasm or developmental condition of endothelial origin”, which may relate to either haemangioma or vascular malformations. In most of the reported cases, intraosseous haemangiomas (also called cavernous or central haemangiomas) appear to be slow-flow malformations.
The WHO classification is no longer appropriate to describe vascular tumours or malformations and should be replaced by the ISSVA classification.
To illustrate this confusion, we reviewed all clinical, radiological, and pathological characteristics of some of the so-designated intraosseous haemangiomas.
Materials and methods
We conducted a retrospective study from 2006 to 2013, using the clinical records database of our maxillofacial surgery unit. Three children diagnosed histologically with an intraosseous haemangioma were identified. A chart review and computed tomography (CT) scan analysis was conducted independently by two surgeons and one radiologist. A new pathological examination was conducted by three independent pathologists, and the cases were classified according to the WHO and the ISSVA classifications ( Table 2 ).
Demographic information (age, gender), clinical data (clinical history, tumour localization, swelling, symptoms, clinical examination), and radiological characteristics (bone lysis, cortical bone invasion, soft tissue invasion, calcification, medullar bone involvement) were analyzed.
Sections 3 μm in thickness were analyzed with haematoxylin–eosin–safranin (HES). Immunohistochemical staining was performed for GLUT-1 (marker for immature haemangioma), CD34 (positive in endothelial cells), D2-40 (marker for lymphatic endothelium), and smooth muscle actin (SMA; marker for mature pericytes).
Three patients, two males and one female (mean age 8 years, range 2 months to 12 years), were included in the study. None had a lesion at birth. In one patient, the lesion was discovered during a random panoramic X-ray. The other two presented a rapidly growing swelling, one at the age of 2 months and the other at 12 years. The lesions were located in the maxilla ( n = 2) and the mandible ( n = 1). One patient had bluish skin and mucosa. A summary of the clinical, radiological, and pathological characteristics of these three patients is given in Table 3 .
|Patient 1||Patient 2||Patient 3|
|Demographic data||Age||2 months||12 years||12 years|
|Clinical data||Presence at birth||No||No||No|
|Symptoms||Rapidly growing swelling||Asymptomatic||Rapidly growing swelling|
|Radiological data||Lytic/condensing||Condensing and lytic||Lytic||Lytic|
|Radiological characteristics||Sunburst pattern||Honeycomb pattern||Soap bubble pattern|
|Soft tissue involvement||No||No||No|
|Cortical bone expansion||Yes||Yes||Yes|
|Pathological examination||HES||Thin-walled cavernous vessels||Small and medium tortuous vessels||Solid sheets and cords of endothelial cells|
|Single-layered endothelial cells||Flat endothelium||Distended vessels|
|Fibrous stroma||Loosely collagenous stroma||Fibrous stroma|
|Normal number of mast cells||Normal number of mast cells||Normal number of mast cells|
|No endothelial hyperplasia||No endothelial hyperplasia||No endothelial hyperplasia|
|CD34||Positive (endothelial cells)||Positive (endothelial cells)||Positive (endothelial cells)|
|SMA||Positive: capillary vessels and pericytes||Positive: large vessels and pericytes||Positive: endothelial aggregates and channels|
|Initial pathological diagnosis||Intraosseous haemangioma||Intraosseous haemangioma||Intraosseous haemangioma|
|WHO classification||Central haemangioma with cavernous components||Central haemangioma with capillary components||Central haemangioma with mixed cavernous and capillary components|
|ISSVA classification||Venous malformations||Capillary malformations||Mixed (venous–capillary malformations)|
CT scans showed one condensing and lytic lesion and two lytic lesions. The pattern of the tumour showed a heterogeneous distribution: sunburst ( n = 1), honeycomb ( n = 1), and soap bubble ( n = 1). There was no involvement of the soft tissues. The cortical bone was expanded in all of these cases ( Figs. 1–3 ).