Endoscopic View of Cholesterol Granuloma of the Maxillary Sinus

A 70-year-old woman was referred to our hospital for evaluation of chronic cough, with mucopurulent rhinorrhea for 6 months. She had no history of underlying systemic disease or relevant facial trauma. She had undergone left sinus surgery at a private clinic 6 years before.

Endoscopic examination revealed a small amount of purulent bilateral nasal discharge from the middle meatus. Computed tomography (CT) of the nose and paranasal sinuses showed soft tissue densities in the left ethmoid and maxillary sinuses (Figure 1). A soft tissue density with calcification was seen in the right maxillary sinus (Figure 1).

Figure 1.

Coronal CT of the nose and paranasal sinuses shows soft tissue densities in the left ethmoid and maxillary sinuses. A soft tissue density with calcification (arrow) is seen in the right maxillary sinus. CT indicates computed tomography.

With a provisional diagnosis of left chronic sinusitis and right fungal sinusitis, bilateral endoscopic sinus surgeries (ESS) were performed under general anesthesia. A right uncinectomy and middle meatal antrostomy were performed. A polypoid mass was found in the inferior portion of the maxillary sinus, which was removed with giraffe forceps using a 45° angled endoscope (Figure 2). Thereafter, left ESS was performed. Histopathologic examination confirmed that the mass was composed of numerous sharp-pointed cholesterol clefts and was bounded by multinucleated giant cells and inflammatory cells; the findings were consistent with those of cholesterol granuloma (CG). The postoperative period was uneventful, and there was marked improvement in the patient’s symptoms approximately 3 months after the ESS.

Figure 2.

A and B, A polypoid mass is found in the inferior portion of the right maxillary sinus. C and D, The mass is removed with giraffe forceps using a 45° angled endoscope.

Cholesterol granuloma usually occurs in middle ear or temporal bone diseases. The presence of CG in the sinonasal region is uncommon. Several possible mechanisms of pathogenesis have been suggested; the favored hypotheses underlying the development of CG include impairment of drainage, obstructed ventilation, and hemorrhage into a bony cavity with hemolysis, which may lead to cholesterol precipitation. ¹

Cholesterol granuloma of the maxillary sinus usually manifests as yellowish rhinorrhea. Nasal obstruction is not common as an initial symptom. ² Common intraoperative findings of CG of the maxillary sinus are a totally cystic or partially cystic and solid mass, with bluish, yellowish, or brownish colors. ¹ However, a completely solid, polyp-like mass has rarely been reported.

Characteristic CT findings include a homogeneous, well-circumscribed, and opacified paranasal sinus, with accompanying bone erosion. Adjacent bone resorption may be due to expansion in an enclosed space, but may also be initiated by prostaglandins produced by platelets in a hematoma. ³ The most frequent findings of CG in the maxillary sinus on imaging studies are an opaque antrum or cystic-appearing lesion. An opaque antrum with expansion would be seen if the lesions were present for a long time. The differential diagnosis of sinonasal CG includes a mucocele, cyst, or neoplasm.

Because intrasinus calcifications on CT in patients with sinonasal fungus balls are commonly seen, ⁴ we preoperatively diagnosed our case as having a right maxillary sinus fungus ball. In our case, preoperative CT was unable to identify any definitive findings to verify the diagnosis of a CG, but the diagnosis was made on the basis of histological findings.