Report of a sphenoid sinus lipoma.
Sphenoid sinus opacification on computed tomography carl represent a multitude of etiologies. Such a finding can signify an infectious, inflammatory, congenital, neuronal, vascular, or neoplastic mass. In this article, we describe a case of a lipoma of the sphenoid sinus, and we discuss the differential diagnosis and management of this finding.
Although adipose tumors are common in most parts of the body, (1) they are extremely rare in the nasal cavity and paranasal sinuses. (2) We present a case of a sphenoid sinus lipoma.
A 25-year-old woman presented to an outside community hospital with a chief complaint of headache in the vertex and left retro-orbital area. She also reported fatigue, nasal drainage, and significant nasal congestion. She had a history of allergic rhinitis, for which she had undergone several years of treatment by a primary care physician with nasal steroids and second-generation antihistamines. She had also begun a course of immunotherapy, but it was discontinued when she experienced a systemic reaction.
After unsuccessful treatment of her headaches with antiallergy therapy, computed tomography (CT) was obtained. CT showed opacification and enlargement of the left sphenoid sinus. The patient was prescribed a 4-week course of moxifloxacin and a prednisone taper. However, post-treatment CT showed no change in the sphenoid sinus opacification, although it did demonstrate an intact bony architecture without evidence of a skull base defect (figure 1).
The patient was then referred to our tertiary care medical center for consultation and further evaluation of her persistent left sphenoid opacification. Further questioning revealed no change in her headache symptoms despite medical management. She also denied any history of head or nasal trauma and nasal or sinus surgery. In-office flexible nasal endoscopy revealed a healthy-appearing mucosa in the left sphenoethmoid recess. Her sphenoid os could not be visualized.
The patient underwent image-guided functional endoscopic sinus surgery. A left maxillary antrostomy and total ethmoidectomy were necessary to provide adequate access to the sphenoid sinus. A wide sphenoidotomy was then created, and the mass was partially excised with the use of curved suction and curved instrumentation (figure 2). Because there was significant aeration of the sphenoid sinus inferolaterally into the pterygoid area, and in view of the unknown histologic characteristics of the tumor, a complete resection was not performed.
On histologic examination, sections of the formalinfixed, paraffin-embedded lesion exhibited benign, mature-appearing adipose tissue, with cytologically bland adipocytes and admixed fibrous strands (figure 3). These findings led to the diagnosis of a lipoma.
Postoperatively, the patient did well and experienced a significant alleviation of her headaches. Even so, a 6-month postoperative CT showed persistent opacification of the left sphenoid sinus. In response to concerns about a recurrence of the fatty tumor, a repeat excision with more comprehensive histopathology was performed. During the revision endoscopic sinus surgery, scar tissue within the sphenoid sinus and a fair amount of lipomatous-appearing tissue were seen. An extended sphenoidotomy was performed by drilling the original sphenoidotomy down to the level of the floor of the sinus to allow for greater access to the well-aerated inferior and lateral limits of the sphenoid sinus. The mass was laterally attached to the mucosa, and this mucosa was stripped from the underlying bone to ensure a complete excision. The underlying bone appeared to be healthy, and no abnormalities were seen in the surrounding area.
Histopathology revealed a mostly reactive stroma with fibrosis, dystrophic calcification, evidence of previous hemorrhage, and areas of admixed mature adipocytes. Cytogenetics revealed a normal female karyotype. The histologic information all supported the final diagnosis of a lipoma.
[FIGURE 1 OMITTED]
Of paramount importance in this case was the authenticity of the diagnosis of a lipoma. In the absence of a macroscopic capsule, fat and lipoma are histologically indistinguishable since they are composed of identical mature fibroadipose elements. A diagnosis of low-grade liposarcoma was excluded in our case on the basis of an absence of several elements: lipoblasts, nonlobular architecture, a spindle-cell component, mitotic activity, and cellular pleomorphism. Although a significant reactive component with a mixed population of inflammatory and myofibroblastic cells was present in the re-excision specimen, there were no architectural or cytologic features suggestive of a sarcoma.
In 1977, Fu and Perzin reported a case of a maxillary sinus lipoma in a 34-year-old woman, and they also referenced reports of 2 other maxillary sinus lipomas dating back to 1915 and 1938. (2) More recently, Lanisnik and Didanovic reported a case of sphenoclival intraos seous lipoma. (3) They also successfully treated this benign lesion with endoscopic surgery. Lipomas have been described in several other unusual locations, including the pericardium, (4) spinal cord, (5) tonsil, (6) and pancreas. (7)
[FIGURE 2 OMITTED]
Aside from adipose-type tumors, the differential diagnosis of a sphenoid sinus mass includes many benign and malignant lesions. Benign processes include nasal polyps, mucoceles, meningoencephaloceles, chrondromas, osteomas, ossifying fibromas, and cementomas. Vascular anomalies, including an internal carotid artery aneurysm, should also be considered, especially in the sphenoid sinus. Intermediate neoplasms include inverted papillomas, meningiomas, chordomas, gliomas, hemangiomas, and hemangiopericytomas. Finally, malignant lesions to consider include squamous cell carcinomas, malignant melanomas, craniopharyngiomas, lymphomas, adenocarcinomas, adenoid cystic carcinomas, osteosarcomas, chondrosarcomas, nasopharyngeal carcinomas, and esthesioneuroblastomas.
[FIGURE 3 OMITTED]
Proper imaging and biopsy are necessary to make the diagnosis and determine treatment for patients with a sphenoid sinus mass. In addition, thorough follow-up to confirm resolution of symptoms and the accuracy of the pathologic findings is important when rare findings are encountered.
(1.) Rosenberg A. Bones, joints, and soft tissue tumors. In: Cotran RS, Kumar V, Collins T, eds. Robbins Pathologic Basis of Disease. 6th ed. Philadelphia: W.B. Saunders; 1999.
(2.) Fu YS, Perzin KH. Non-epithelial tumors of the nasal cavity, paranasal sinuses and nasopharynx: A clinicopathologic study. VIII. Adipose tissue tumors (lipoma and liposarcoma). Cancer 1977;40(3):1314-17.
(3.) Lanisnik B, Didanovic V. Sphenoclival intraosseus [sic] lipoma: Case report and literature review. Skull Base 2007;17(3):211-14.
(4.) Durak D, Eren B. Pericardial lipoma: An autopsy case and review of the literature. J Forensic Sci 2007;52(4):949-50.
(5.) Blount JP, Elton S. Spinallipomas. Neurosurg Focus 2001;10(1):e3.
(6.) Wang CP, Kwan PC, Ho CY. Lipoma of the palatine tonsil. J Formos Med Assoc 2007;106(8):673-5.
(7.) Sato K, Takagi H, Ishibashi A, et al. Small pancreatic lipoma: Case report and literature review. Hepatogastroenterology 2007;54(77): 1582-4.
Greg Eldon Davis, MD, MPH; Lauren Elaine Kernochan, MD; Lawrence D. True, MD
From the Department of Otolaryngology-Head and Neck Surgery (Dr. Davis) and the Department of Pathology (Dr. True), University of Washington School of Medicine, Seattle; and the Department of Pathology, Cottage Hospital, Santa Barbara, Calif. (Dr. Kernochan).
Corresponding author: Greg E. Davis, MD, MPH, Box 356515, 1959 NE Pacific St., Seattle, WA 98195. Email: email@example.com
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|Title Annotation:||ORIGINAL ARTICLE|
|Author:||Davis, Greg Eldon; Kernochan, Lauren Elaine; True, Lawrence D.|
|Publication:||Ear, Nose and Throat Journal|
|Article Type:||Case study|
|Date:||Feb 1, 2012|
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