Huge Cholesterol Granuloma in Nasoseptal Region

A 55-year-old male patient was presented with the complaints of nasal obstruction, anosmia, epiphora, and midfacial pressure perception persisting for past 5 months. His past history revealed a traumatic facial airbag crash during a car accident approximately 9 years ago. Rigid nasal endoscopic examination showed a smooth submucosal midline mass involving the both sides of the nasal septum. Noncontrast paranasal sinus computed tomography (CT) exhibited a well-demarcated and centrally located cystic lesion of 5.2 cm × 3.8 cm in the nasal septum with evident cartilage and bone destruction. The lesion was extending cranially to both frontal sinuses with apparent erosion of the inferior and posterior sinus walls (Figure 1A-C). Affirming the CT findings, T1- and T2-weighted magnetic resonance imaging (MRI) scans exhibited a hyperintense and heterogeneous cystic mass. Frontal dural contrast enhancement was evident but no communication between the bilateral frontal regions and related epidural spaces was reported (Figure 1D-F). Then, we performed a transnasal endoscopic surgery with a radiological diagnosis of an unspecified cystic mass. The yellowish viscous cyst fluid was evacuated, trailed by a microdebrider-assisted marsupialization procedure (Figure 2). Histopathological examination indicated a final diagnosis of cholesterol granuloma (CG). No complication was observed with a well-healed nasal cavity on endoscopic examination (Figure 3). The patient was in good condition with no recurrences at the 18 months of follow-up.

Figure 1.

Axial and coronal computerized tomography images (A-C) showing a cystic lesion, filling the nasal cavity, and expanding into the both frontal sinuses with apparent erosion of the posterior tables of the frontal bones (arrow). Postcontrast-enhanced, axial T2-weighted (D-F) magnetic resonance imaging scans displaying a hyperintense and heterogeneous cystic lesion without any communication with the frontal epidural space.

Figure 2.

Demonstration of the patient’s right nasal cavity during the endoscopic nasal surgery: (A) Cholesterol granuloma cyst compressing the middle turbinate and embedding in to the lamina papricea. B and C, Aspiration of the viscous yellowish cyst fluid from the cavity and dissection of the anterior and lateral walls of the cyst. D, Endoscopic view of the cyst following the aspiration of cyst fluid and the remaining debris. MT indicates middle turbinate; *, viscous yellowish cyst fluid; **, posterior wall of the cyst.

Figure 3.

Endoscopic view of the nasal cavity at postoperative first month. MT indicates middle turbinate; *, posterior choanae.

The precise pathogenesis of CG has not been fully elucidated yet, but 2 explanatory hypotheses have been proposed, namely the obstruction-vacuum- and the exposed marrow hypotheses, respectively. ¹ Both hypotheses proposed that the trapped blood in the closed cavities undergoes degeneration, which triggers an inflammatory macrophage-mediated granulomatous foreign body reaction against the hemosiderin that emerges during the breakdown process of hemorrhagic blood products. ^2,3 Cholesterol granuloma may be precipitated by trauma, surgery, or recurrent sinusitis attacks leading to bleeding into a closed bony cavity and accumulation of blood in a space with interrupted ventilation. ^1,2,4 The CGs are more common in the fifth decade of life with a male predominance, and triggering previous trauma or surgery history is present in 14% and 11% of all cases, respectively. ⁵ The most frequently reported location of CG is frontal sinuses. ⁵ Although the CG-related symptoms may vary widely depending on the primary site of involvement and its local extensions, yet most cases present with nonspecific symptoms. Our present case had a history of facial trauma which might have triggered the advancement of a septal hematoma, which might have enlarged and destroyed the cartilaginous and bony structures during the past 9 years.

Although nasal cavity and paranasal sinus CGs are exceedingly rare, yet, they share some radiographic and pathological characteristics which serve useful for accurate diagnosis and treatment guidance. Diagnosis of the CG mainly relies upon the radiologic findings. But, sadly, CT findings are usually nonexplicit, although a relatively homogenous and well-circumscribed cystic mass with deaeration of the involved sinus and destruction of bony structures are typically demonstrable in most cases. The MRI scans show characteristic high signal intensity on both T1- and T2-weighted images owing to its high-lipid cholesterol content, except for the walls of the cyst due to the accumulation of paramagnetic methemoglobin. ^{4 -6} The differential diagnoses of CGs for the most part include the=mucoceles and meningoceles. Mucoceles show low- and high-signal intensities on T1- and T2-weighted images, but signal characteristics may vary depending on their fluid contents. ⁴ Meningoceles are easily diagnosed by MRI with its respective hypo- and hyperintense characteristics on T1- and T2-weighted images and presence of demonstrable bone defects. Importantly, presence of bone erosion mandates the exclusion of malignant causes. Final diagnosis of CG is always confirmed by the pathological examination. Since the CG represents an inflammatory response against the hemosiderin produced by breakdown of the extravasated hemoglobin, histological examinations typically show abundant cholesterol clefts surrounded by inflammatory cells, multinucleated foreign body giant cells, and macrophages filled with hemosiderin in the fibrous granulation tissue. ^6,7

The broadly acknowledged definitive treatment of CG is complete surgical resection, which reestablishes the drainage and ventilation problems in the influenced territory. Albeit various surgical approaches have been described for CGs with regard to the variations in their primary locations and local extensions, ^3,6,8,9 yet, endoscopic nasal approach is adequate for most occasions, and recurrences are rarely reported after this approach. ⁵

In conclusion, to our best knowledge, this is the second nasoseptal CG report in the literature. Our observation presented here suggested that, irrespective of their locally destructive nature, CGs are benign conditions, which might be cured with local surgical resections.