A 26-year-old African patient presented with a rapidly growing lesion that expanded the mandible. There was bone destruction on the radiograph and therefore malignancy was suspected. On biopsy, the lesion was intraosseous and was cavitated. There was profuse bleeding and a small biopsy of the lining was taken. The pathologist reported osteoclast-like giant cells and granulation tissue with blood clots.

An aneurysmal bone cyst is a type of benign bone tumor that can occur in the jawbone. It is called an “aneurysmal” because it contains blood-filled spaces that can resemble the sac-like structure of an aneurysm. These cysts are relatively rare, accounting for less than 1% of all bone tumors.

Clinically, an aneurysmal bone cyst can be dramatic because it can grow rapidly and attain a large size. This can cause symptoms such as pain, swelling, and displacement of nearby teeth. When a biopsy is performed to confirm the diagnosis, bleeding can be profuse due to the presence of fragile blood vessels within the cyst. In some cases, a blood transfusion may be necessary to manage the bleeding.

It is important to note that aneurysmal bone cysts often form around an underlying primary lesion, such as a vascular malformation or bone tumor. Therefore, it is crucial to thoroughly evaluate any aneurysmal bone cyst to determine if there is an underlying primary lesion that needs to be addressed. Treatment options for aneurysmal bone cysts may include surgical excision or minimally invasive procedures such as sclerotherapy or curettage.

As a dental student, it is important to be aware of aneurysmal bone cysts as a potential differential diagnosis when evaluating patients with jaw pain, swelling, or other symptoms. If you suspect a patient may have an aneurysmal bone cyst, referring them to an oral and maxillofacial surgeon for further evaluation and management is important.