**2. Atypical case**

A 14-year-old male patient presented with chief complaint of right-sided nasal blockage and bulging of the right eye of 6-month duration. The patient was medically free. He was in his usual state of health till 6 months prior to presentation to our clinic when he started to have nasal obstruction in the right side along with right eye proptosis. Local examination of the face showed right proptosis, with bulging around the right medial canthus and lateral wall of the nose. Nasal endoscopy by 00 rigid telescope showed poorly defined swelling in the right nasal cavity. Magnetic resonance imaging (MRI) of the nose and paranasal sinuses revealed multiple fluid-fluid levels of varying signal intensities ranging from very bright signal to a very low signal on T2-weighted image, suggestive of aneurysmal bone cyst (**Figures 1** and **2**). The patient was admitted and cleared by the ophthalmologist. Endoscopic sinus surgery

**Figure 1.** *MRI, coronal view showing multicystic lesion with varying intensity.*

**93**

*Aneurysmal Bone Cyst in Sino-nasal Region DOI: http://dx.doi.org/10.5772/intechopen.84939*

**3. Aneurysmal bone cyst in general**

*Endoscopic intraoperative view of static blood inside the lesion.*

**3.2 Characteristics of aneurysmal bone cyst**

**3.3 The name of aneurysmal bone cyst**

**3.4 Demographics of aneurysmal bone cyst**

**3.1 History**

**Figure 3.**

fluid blood [5].

was carried out to remove the nasal swelling, which showed multiple cystic swellings that were filled with blood (**Figure 3**), and tissue specimens were sent for histopathology. The histopathological specimens, on gross appearance, consist of friable hemorrhagic material that is often gritty. In en bloc resections, cyst and cortical destruction was appreciated. Microscopical results showed stroma composed of fibroblasts, multinucleate giant cells, and bone, as well as cystic spaces often filled with blood with an increased number of giant cells lining the cavity. The final histopathological diagnosis was ABC. The patient had smooth recovery postoperatively and was asymptomatic in

6 months of follow-up but unfortunately lost for subsequent follow-up after.

Aneurysmal bone cysts (ABCs) were first described in 1942, by Drs. Jaffe and Lichtenstein. Typically, the described lesion was thin-walled, involving the pelvic and spine region, and they were confronted underneath large hole containing much

ABC is considered as uncommon benign nonneoplastic vascular lesion of the

ABC is misnomer, as these lesions are neither aneurysmal in origin nor truly cystic in histopathology, with no endothelial wall. Instead, these are benign expansile lesions, within the bone, forming cavities that are filled with blood and lined by

It is found mostly during childhood and adolescence, with median age of 13 years. About 90% of the ABCs lesions are found prior to age of 30. ABCs are more

bones characterized by the presence of numerous blood-filled, usually nonepithelized cystic cavities. It is rapidly expanding and locally destructive [6].

proliferative fibroblasts, giant cells, and trabecular bone [7].

common in female patients, with male to female ratio of 1:1.6 [7, 8].

**Figure 2.** *MRI, axial view showing fluid-fluid levels in the lesion.*

*Aneurysmal Bone Cyst in Sino-nasal Region DOI: http://dx.doi.org/10.5772/intechopen.84939*

*Rhinosinusitis*

**2. Atypical case**

A 14-year-old male patient presented with chief complaint of right-sided nasal blockage and bulging of the right eye of 6-month duration. The patient was medically free. He was in his usual state of health till 6 months prior to presentation to our clinic when he started to have nasal obstruction in the right side along with right eye proptosis. Local examination of the face showed right proptosis, with bulging around the right medial canthus and lateral wall of the nose. Nasal endoscopy by 00 rigid telescope showed poorly defined swelling in the right nasal cavity. Magnetic resonance imaging (MRI) of the nose and paranasal sinuses revealed multiple fluid-fluid levels of varying signal intensities ranging from very bright signal to a very low signal on T2-weighted image, suggestive of aneurysmal bone cyst (**Figures 1** and **2**). The patient was admitted and cleared by the ophthalmologist. Endoscopic sinus surgery

**92**

**Figure 2.**

**Figure 1.**

*MRI, axial view showing fluid-fluid levels in the lesion.*

*MRI, coronal view showing multicystic lesion with varying intensity.*

**Figure 3.** *Endoscopic intraoperative view of static blood inside the lesion.*

was carried out to remove the nasal swelling, which showed multiple cystic swellings that were filled with blood (**Figure 3**), and tissue specimens were sent for histopathology. The histopathological specimens, on gross appearance, consist of friable hemorrhagic material that is often gritty. In en bloc resections, cyst and cortical destruction was appreciated. Microscopical results showed stroma composed of fibroblasts, multinucleate giant cells, and bone, as well as cystic spaces often filled with blood with an increased number of giant cells lining the cavity. The final histopathological diagnosis was ABC. The patient had smooth recovery postoperatively and was asymptomatic in 6 months of follow-up but unfortunately lost for subsequent follow-up after.
