Diverse imaging characteristics of a mandibular intraosseous vascular lesion
A 30-year-old female patient presented with a painful swelling in the left mandibular anterior region. The swelling had been enlarging gradually and had been symptomatic for 2 months. No history of trauma preceded the swelling. The patient's physical examination revealed no abnormality, and the vital signs were within the normal range. Facial asymmetry due to a solitary diffuse swelling measuring about 3 cm×2 cm on the left side of the mandible was evident. Tenderness and a local rise in temperature were noted, and the swelling was soft in consistency. Intraorally, the oval-shaped swelling was 3 cm×3 cm in size, extending from the left mandibular canine to the distal side of the left mandibular second premolar. The overlying mucosa appeared to be slightly bluish with a smooth and shiny surface (). On palpation, the swelling was soft and fluctuant in the buccal aspect. The adjacent left mandibular canine and the first premolar revealed grade I mobility. The clinical differential diagnoses considered were dentigerous cyst, unicystic ameloblastoma, adenomatoid odontogenic tumour, central giant-cell granuloma, aneurysmal bone cyst, and intraosseous vascular malformation and/or intraosseous hemangioma.\nA routine radiographic examination was performed. The resulting panoramic radiograph revealed a well-defined multilocular radiolucency extending from the left mandibular canine to the left mandibular second premolar with the presence of small loculations and fine trabeculae (). The roots of the left mandibular premolars were displaced laterally and showed no resorption. The mandibular occlusal radiograph showed bone spicules radiating from the buccal margins of the lesion, resembling a "sunburst" appearance (). On the intraoral periapical radiograph, a radiolucent lesion with small loculations and a fine trabecular pattern, and having a honeycomb appearance, was clearly appreciable (). The radiographic differential diagnosis of a multilocular lesion of the jawbone with a honeycomb pattern includes ameloblastoma, odontogenic myxoma, central giant-cell granuloma, multiple myeloma, aneurysmal bone cyst, and fibrous dysplasia. The multicystic (solid) variant of ameloblastoma typically appears multiloculated with internal septations manifested as a honeycomb or soap-bubble appearance. Odontogenic myxoma might present itself as an expansile, multilocular lesion with a tennis-racket or honeycomb-like pattern. Central giant-cell granuloma might appear as a poorly defined unilocular radiolucency or multilocular radiolucency with scalloped borders and is characterized by wispy ill-defined trabeculation. An aneurysmal bone cyst presents itself as a ballooned-out multilocular radiolucency with a honeycomb or soap-bubble appearance. These lesions show tooth displacement more commonly than root resorption. In our case, the "sunburst" appearance helped differentiate among the abovementioned lesions, all of which had a multilocular honeycomb appearance. Osteosarcoma also produces a sunburst appearance in addition to many different periosteal reactions, including an onion-skin appearance and asymmetric broadening of the periodontal ligament space. Fibrous dysplasia might also present itself with indistinct borders and a ground-glass appearance, while multiple myeloma might present itself with multiple lesions rather than multilocular lesions restricted to one jawbone.\nNeedle aspiration was performed on the buccal aspect of the lesion in the second premolar region, and the process yielded 3 mL of frank blood (). The presence of blood, demonstrated by the large number of erythrocytes, was confirmed through cytology, and a strong likelihood of the existence of a vascular lesion was established. Aneurysmal bone cyst, intraosseous vascular malformation, or intraosseous hemangioma was considered in the differential diagnosis following needle aspiration.\nMagnetic resonance imaging (MRI) and computed tomographic angiography (CTA) with three-dimensional (3D) reconstruction were performed. The computed tomography (CT) images showed an expansile multiocular lesion with an indistinct periosteal reaction on the buccal cortex. Internal loculations were not clearly evident in the CT scan. The axial CT scan images showed a trabeculated lesion in the left hemi-mandible, with feeder vessels supplying the vascular lesion. A CT angiogram was obtained; it showed that the branches of the right external carotid and the facial artery were in close proximity to the lesion. However, the peripheral feeder vessel was not determined, and therefore, we considered the left inferior alveolar artery to be the feeder (). Three-dimensional CT angiogram images showed a vascular lesion and the peripheral feeder vessel. The CT angiogram did not reveal any areas of nidus formation or entangled focus of blood vessels, as normally noted in the case of vascular malformations ().\nThe T1-weighted MR images (T1WI) obtained using fat suppression (FS) showed a lesion with an iso-intense signal. Signal voids were not detected, suggesting a slow flow lesion. Internal loculations were noted in the coronal plane and the axial plane, suggesting multilocularity. The coronal T1WI () and the axial T1WI () showed an expansile low-intensity lesion in the marrow of the left hemi-mandible with a cortical break. The T2-weighted images (T2WI) showed hyperintense signals, thus confirming a vascular lesion (). Axial T2WI showed high signal intensity and an expansile lesion in the marrow of the left hemi-mandible with a cortical break. MRI revealed the fluid-fluid levels in the aneurysmal bone cyst in T1WI, thus helping to differentiate it from vascular malformation. Further, Gd-T1WI showed heterogeneous signal intensity in the osteosarcoma, which was absent in vascular malformations. A slow flow malformation in the Gd-T1WI might sometimes present a "bubbly" appearance, which was seen in aneurysmal bone cyst (ABC) as well.,\nThe lesion was excised, and on microscopic examination (), numerous small and a few dilated capillaries lined with plump endothelial cells were noted; a few areas showed active endothelial proliferation forming an indistinct vascular lamina. The final diagnosis was given as intraosseous vascular malformation of the left mandibular region based on the clinical, imaging and histological features. The 12-month follow-up did not reveal any recurrence.