The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
Brief Clinical Studies
5. Choi HJ, Kim MS, Lee YM. The endoscopic treatment of blow-out fracture. J Korean Cleft Palate Craniofac Assoc 2002;3:173–178 6. Saunders CJ, Whetzel TP, Stokes RB, et al. Transantral endoscopic orbital floor exploration: a cadaver and clinical study. Plast Reconstr Surg 1997;100:575–581 7. Smith B, Regan WF Jr. Blow out fracture of the orbit: mechanism and correction of internal orbital fracture. Am J Ophthalmol 1957; 44:733–739 8. Park MS, Kim YJ, Kim H, et al. Prevalence of diplopia and extraocular movement limitation according to the location of isolated pure blowout fractures. Arch Plast Surg 2012;39:204–208 9. Glassman RD, Manson PN, Vanderkolk CA, et al. Rigid fixation of internal orbital fractures. Plast Reconstr Surg 1990;86:1103–1106 10. Polley JW, Ringler SL. The use of Teflon in orbital floor reconstruction following blunt facial trauma: a 20-year experience. Plast Reconstr Surg 1987;79:39–42 11. Rubin PAD, Bilyk RJ, Shore JW. Orbital reconstruction using porous polyethylene sheets. Ophthalmology 1994;101:1697–1704 12. Geer AJ, Lokeh A, Aldridge JH, et al. Safety of titanium mesh for orbital reconstruction. Ann Plast Surg 2002;48:1–7 13. Dougherty WR, Wellisz T. The natural history of alloplastic implant in orbital floor reconstruction: an animal model. J Craniofac Surg 1994;5:26–30 14. Eun SC, Heo CY, Baek RM, et al. Survey and review of blow out fracture. J Korean Soc Plast Reconstr Surg 2007;34:600–605 15. Ali SN, Gill P, Oikonomou D, et al. The combination of fibrin glue and quilting reduces drainage in the extended latissimus dorsi flap donorsite. Plast Reconstr Surg 2010;125:1615–1619 16. Man D, Plosker H, Winland-Brown JE. The use of autologous platelet-rich plasma (platelet gel) and autologous platelet-poor plasma (fibrin glue) in cosmetic surgery. Plast Reconstr Surg 2001; 107:229–237 17. Radosevich M, Goubran HI, Burnouf T. Fibrin sealant: scientific rationale, production methods, properties, and current clinical use. Vox Sang 1997;72:133–143
Osteoplastic Flap Approach Versus Orbitotomy in Case of Orbitofrontal Cholesterol Granuloma Abdulkadir Imre, MD,* Ercan Pinar, MD,* Irem Paker, MD,† Seher Saritepe Imre, MD,‡ Ridvan Duran, MD,* Sedat Ozturkcan, MD* Abstract: A 44-year-old man developed a slow-growing painless left superolateral orbital mass that extended into the frontal sinus with a complaint of ptosis. Magnetic resonance imaging revealed a heterogenous hyperintense lesion confined to the left frontal bone From the Departments of *Otorhinolaryngology, †Pathology, ‡Ophtalmology, Izmir Katip Çelebi University Ataturk Training and Research Hospital, Izmir, Turkey. Received July 4, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Abdulkadir Imre, MD, Department of Otorhinolaryngology, Izmir Katip Çelebi University Ataturk Training and Research Hospital, 9200/1 sk No. 5 D:10 Camlikent Sitesi Karabaglar/Izmir, 35150 Turkey; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001296
e36
and superior orbit. The osteoplastic frontal sinus approach was performed to drain supraorbital cholesterol granuloma cyst and for curetting the capsule. Orbitofrontal cholesterol granuloma characteristically arises in the diploe of the superolateral frontal bone. The traditional approach for a primarily orbitofrontal cholesterol granuloma is the transorbital approach including anterior orbitotomy or lateral orbitotomy.However, the osteoplastic approach should be kept in mind as an alternative aprroach for the management of supraorbital lesions in patients with well-pneumatized frontal sinus. Key Words: Cholesterol granuloma, pneumosinus dilatans, frontal sinus, osteoplastic flap, orbitotomy
C
holesterol granuloma is a chronic inflammatory process associated with foreign body reaction to hemorrhage-related cholesterol crystals. In the head and neck region, cholesterol granuloma most frequently arises in the pneumatized air cell of temporal bone, particularly in the petrous apex and middle ear cavity. However, it has been reported less frequently in several locations, such as the paranasal sinuses, orbit, frontal bone, breast, lungs, and peritoneum.1 Cholesterol granuloma is a benign lesion, but lesions involving the frontal bone erode adjacent facial skeleton and this slowly expanding lesion eventually breaks into the orbit, frontal sinus, skull base, or intracranial structures.2 Significant percentage of these lesions are treated by the ophthalmologist alone as other orbital tumors. However, collaboration with a neurosurgeon or a surgeon of eyes, nose, and throat may be required for larger and intracranial extended tumors. Here, we present a case of orbitofrontal cholesterol granuloma in a patient with pneumosinus dilatans frontalis, which enables surgical access to the orbital roof through an osteoplastic flap approach. The diagnosis and management of this lesion were discussed.
CASE REPORT A 44-year-old man was referred to our clinic with a complaint of left supraorbital mass and ptosis for the past 3 months. The patient reported a 2-year history of left upper eyelid fullness. His vision was 20/20, right eye and left eye, respectively. Ptosis and inferior vertical dystopia were noted on the left eye (Fig. 1). Ocular movement was completely restricted in the superior direction, whereas it is normal in other directions. There was no proptosis or enophthalmos noted. A 2 2-cm firm mass was palpable in the superolateral orbital region. The remaining ophthalmologic and otolaryngologic examinations were unremarkable. A computed tomographic scan revealed a well-defined supraorbital mass measuring 2.7 2.8 3.7 cm in the well-aerated frontal sinus with superior orbital wall erosion. Magnetic resonance imaging (MRI) demonstrated a predominantly hyperintense and heterogenous lesion on both T1-weighted and T2-weighted images, with inferior displacement of the ocular globe and intraconal contents. In T2 sequences, a thick hypointense ring around the lesion was noted
FIGURE 1. Preoperative and postoperative view of the patient. Ptosis and inferior vertical dystopia of the globe (left) as well as the scar of the brow incision at postoperative 1 month (right) are shown.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
FIGURE 2. Computed tomographic (A) and T2-weighted MRI (B) images show hyperintense and heterogenous supraorbital lesion in the well-aerated frontal sinus. C, Postoperative T2-weighted MRI at the 12-month follow-up.
(Fig. 2). The patient underwent an osteoplastic frontal sinus surgery through a left brow incision. Caldwell view radiograph of the patient was trimmed and sterilized as well as used as a template. A drill was used to create osteotomies, and osteoplastic flap was elevated. The left supraorbital lesion was exposed. The anterior and middle part of the orbital roof had been eroded, and the cyst wall adhered tightly to the periorbit. The bone in the superotemporal orbital area was substantially destroyed by the tumor, but orbital rim was intact. The viscous yellowish content was aspirated, pseudocapsule was curetted, cyst wall adhered to the periorbit was removed by sharp dissection as far as possible, and surrounding intact bone was scarified by using drill. The operative field was closed in a routine fashion, and fat obliteration of the frontal sinus was not performed. Histopathologic examination revealed numerous cholesterol clefts surrounded by granulomatous inflammation containing giant cells with hemosiderin deposition, which confirmed cholesterol granuloma (Fig. 3). The next day of the operation, the ocular movement and inferior displacement of his left eye were improved. However, the globe had completely returned to the normal position 2 weeks later. Magnetic resonance imaging evaluation showed no recurrence at the 12-month follow-up (Fig. 2C).
Brief Clinical Studies
hemosiderin, within a fibrous connective tissue, characterizes a cholesterol granuloma.6 The definitive management of cholesterol granuloma is drainage of the content, curettage or total removal of the cyst wall, and drilling of the tumor bed and surrounding intact bone.9 Surgical approaches to orbital tumors depend on tumoral relationships, size, location, goal of the surgery (biopsy or total excision), and possible nature of the lesion. In general, anterior lesions are treated via transorbital approaches, whereas lesions of the posterior third are best managed via extraorbital approaches. The anterior and lateral orbitotomies are the most preferred approaches to superolateral extraconal orbital lesions.10–12 Transcranial approach targets intraorbital lesions through the roof and lateral walls of the orbit. This approach is ideally suited for apical and superior orbital fissure lesions.12 In our case, pneumosinus dilatans was diagnosed through computed tomography. Pneumosinus dilatans is an abnormal enlargement of the sinus with extension beyond the normal boundaries of the bone.13 In the current case, pneumatization of the frontal sinus was extended to the supraorbital region and orbital roof because of pneumosinus dilatans. Frontal bossing and prominence of the supraorbital ridge were observed because of outward expansion of the sinus as well. Therefore, the frontal sinus osteoplastic approach was preferred. Contrary to the anterior orbitotomy approach, osteoplastic flap provided wide exposure without retracting the orbit in this case. The rationale for our proposed method of surgical management is that, if the frontal sinus pneumatization extends through the supraorbital region and orbital roof, osteoplastic flap approach provides wide exposure for supraorbital lesions.
REFERENCES
DISCUSSION Orbitofrontal cholesterol granuloma is a rare entity that is most frequently observed in middle-aged men and typically occurs within the frontal bone overlying the lacrimal fossa. The most common presenting symptoms are inferomedial displacement of the globe and proptosis.3 Diagnosis is based on radiologic imaging findings, which are paramount in the preoperative evaluation and differential diagnosis of cholesterol granuloma. Computed tomography usually shows an osteolytic extraconal lesion in the superolateral orbit. Magnetic resonance imaging can be of most value in the diagnosis of cholesterol granuloma and typically shows high signal intensity on both T1- and T2-weighted images owing to the its high lipid cholesterol content. The differential diagnosis of orbitofrontal cholesterol granuloma includes lacrimal gland neoplasms, metastatic tumors, aneurysmal bone cysts, epidermoid cysts, and mucoceles.7,8 The pathogenesis of cholesterol granuloma is stil unclear. Several possible mechanisms of pathogenesis have been suggested, including the obstruction-vacuum theory and exposed marrow theory.4,5 Hemorrhages into a bony cavity with hemolysis may lead to cholesterol precipitation. Microscopically, the encompassing of cholesterol clefts by foreign body giant cells in the presence of
FIGURE 3. Cholesterol clefts surrounded by granulomatous inflammation containing giant cells with hemosiderin deposition (hematoxylin-eosin stain).
1. McNab AA, Wright JE. Orbitofrontal cholesterol granuloma. Ophthalmology 1990;97:28–32 2. Ochiai H, Yamakawa Y, Fukushima T, et al. Large cholesterol granuloma arising from the frontal sinus: case report. Neurol Med Chir (Tokyo) 2001;41:283–287 3. Sia Dl, Davis G, Selva D. Recurrent orbitofrontal cholesterol granuloma: case report. Orbit 2012;31:184–186 4. Selva D, Phipps SE, O'Connell JX, et al. Pathogenesis of orbital cholesterol granuloma. Clin Experiment Ophthalmol 2003; 31:78–82 5. Jackler RK, Cho M. A new theory to explain the genesis of petrous apex cholesterol granuloma. Otol Neurotol 2003;24:96–106 6. Ko MT, Hwang CF, Kao YF, et al. Cholesterol granuloma of the maxillary sinus presenting as sinonasal polyp. Am J Otolaryngol 2006;27:370–372 7. Chow LP, McNab AA. Orbitofrontal cholesterol granuloma. J Clin Neurosci 2005;12:206–209 8. Arat YO, Chaudhry IA, Boniuk M. Orbitofrontal cholesterol granuloma: distinct diagnostic features and management. Ophthal Plast Reconstr Surg 2003;19:382–387 9. Aferzon M, Millman B, O'Donnell TR, et al. Cholesterol granuloma of the frontal bone. Otolaryngol Head Neck Surg 2002;127: 578–581 10. Okay O, Daglioglu E, Akdemir G, et al. Lateral orbitotomy approach to orbital tumors: report of 10 cases. Turk Neurosurg 2010;20:167–172 11. Prabhakaran VC, Hsuan J, Selva D. Endoscopic-assisted removal of orbital roof lesions via a skin crease approach. Skull Base 2007;17:341–345 12. Bejjani GK, Cockerham KP, Kennerdel JS, et al. A reappraisal of surgery for orbital tumors. Part I: extraorbital approaches. Neurosurg Focus 2001;10:E2 13. Desai NS, Sabo SS, Khandelwal A, et al. Pneumosinus dilatans: is it more than an aesthetic concern? J Craniofac Surg 2014;25:418–421
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
e37
Brief Clinical Studies
5. Choi HJ, Kim MS, Lee YM. The endoscopic treatment of blow-out fracture. J Korean Cleft Palate Craniofac Assoc 2002;3:173–178 6. Saunders CJ, Whetzel TP, Stokes RB, et al. Transantral endoscopic orbital floor exploration: a cadaver and clinical study. Plast Reconstr Surg 1997;100:575–581 7. Smith B, Regan WF Jr. Blow out fracture of the orbit: mechanism and correction of internal orbital fracture. Am J Ophthalmol 1957; 44:733–739 8. Park MS, Kim YJ, Kim H, et al. Prevalence of diplopia and extraocular movement limitation according to the location of isolated pure blowout fractures. Arch Plast Surg 2012;39:204–208 9. Glassman RD, Manson PN, Vanderkolk CA, et al. Rigid fixation of internal orbital fractures. Plast Reconstr Surg 1990;86:1103–1106 10. Polley JW, Ringler SL. The use of Teflon in orbital floor reconstruction following blunt facial trauma: a 20-year experience. Plast Reconstr Surg 1987;79:39–42 11. Rubin PAD, Bilyk RJ, Shore JW. Orbital reconstruction using porous polyethylene sheets. Ophthalmology 1994;101:1697–1704 12. Geer AJ, Lokeh A, Aldridge JH, et al. Safety of titanium mesh for orbital reconstruction. Ann Plast Surg 2002;48:1–7 13. Dougherty WR, Wellisz T. The natural history of alloplastic implant in orbital floor reconstruction: an animal model. J Craniofac Surg 1994;5:26–30 14. Eun SC, Heo CY, Baek RM, et al. Survey and review of blow out fracture. J Korean Soc Plast Reconstr Surg 2007;34:600–605 15. Ali SN, Gill P, Oikonomou D, et al. The combination of fibrin glue and quilting reduces drainage in the extended latissimus dorsi flap donorsite. Plast Reconstr Surg 2010;125:1615–1619 16. Man D, Plosker H, Winland-Brown JE. The use of autologous platelet-rich plasma (platelet gel) and autologous platelet-poor plasma (fibrin glue) in cosmetic surgery. Plast Reconstr Surg 2001; 107:229–237 17. Radosevich M, Goubran HI, Burnouf T. Fibrin sealant: scientific rationale, production methods, properties, and current clinical use. Vox Sang 1997;72:133–143
Osteoplastic Flap Approach Versus Orbitotomy in Case of Orbitofrontal Cholesterol Granuloma Abdulkadir Imre, MD,* Ercan Pinar, MD,* Irem Paker, MD,† Seher Saritepe Imre, MD,‡ Ridvan Duran, MD,* Sedat Ozturkcan, MD* Abstract: A 44-year-old man developed a slow-growing painless left superolateral orbital mass that extended into the frontal sinus with a complaint of ptosis. Magnetic resonance imaging revealed a heterogenous hyperintense lesion confined to the left frontal bone From the Departments of *Otorhinolaryngology, †Pathology, ‡Ophtalmology, Izmir Katip Çelebi University Ataturk Training and Research Hospital, Izmir, Turkey. Received July 4, 2014. Accepted for publication August 19, 2014. Address correspondence and reprint requests to Abdulkadir Imre, MD, Department of Otorhinolaryngology, Izmir Katip Çelebi University Ataturk Training and Research Hospital, 9200/1 sk No. 5 D:10 Camlikent Sitesi Karabaglar/Izmir, 35150 Turkey; E-mail: [email protected] The authors report no conflicts of interest. Copyright © 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000001296
e36
and superior orbit. The osteoplastic frontal sinus approach was performed to drain supraorbital cholesterol granuloma cyst and for curetting the capsule. Orbitofrontal cholesterol granuloma characteristically arises in the diploe of the superolateral frontal bone. The traditional approach for a primarily orbitofrontal cholesterol granuloma is the transorbital approach including anterior orbitotomy or lateral orbitotomy.However, the osteoplastic approach should be kept in mind as an alternative aprroach for the management of supraorbital lesions in patients with well-pneumatized frontal sinus. Key Words: Cholesterol granuloma, pneumosinus dilatans, frontal sinus, osteoplastic flap, orbitotomy
C
holesterol granuloma is a chronic inflammatory process associated with foreign body reaction to hemorrhage-related cholesterol crystals. In the head and neck region, cholesterol granuloma most frequently arises in the pneumatized air cell of temporal bone, particularly in the petrous apex and middle ear cavity. However, it has been reported less frequently in several locations, such as the paranasal sinuses, orbit, frontal bone, breast, lungs, and peritoneum.1 Cholesterol granuloma is a benign lesion, but lesions involving the frontal bone erode adjacent facial skeleton and this slowly expanding lesion eventually breaks into the orbit, frontal sinus, skull base, or intracranial structures.2 Significant percentage of these lesions are treated by the ophthalmologist alone as other orbital tumors. However, collaboration with a neurosurgeon or a surgeon of eyes, nose, and throat may be required for larger and intracranial extended tumors. Here, we present a case of orbitofrontal cholesterol granuloma in a patient with pneumosinus dilatans frontalis, which enables surgical access to the orbital roof through an osteoplastic flap approach. The diagnosis and management of this lesion were discussed.
CASE REPORT A 44-year-old man was referred to our clinic with a complaint of left supraorbital mass and ptosis for the past 3 months. The patient reported a 2-year history of left upper eyelid fullness. His vision was 20/20, right eye and left eye, respectively. Ptosis and inferior vertical dystopia were noted on the left eye (Fig. 1). Ocular movement was completely restricted in the superior direction, whereas it is normal in other directions. There was no proptosis or enophthalmos noted. A 2 2-cm firm mass was palpable in the superolateral orbital region. The remaining ophthalmologic and otolaryngologic examinations were unremarkable. A computed tomographic scan revealed a well-defined supraorbital mass measuring 2.7 2.8 3.7 cm in the well-aerated frontal sinus with superior orbital wall erosion. Magnetic resonance imaging (MRI) demonstrated a predominantly hyperintense and heterogenous lesion on both T1-weighted and T2-weighted images, with inferior displacement of the ocular globe and intraconal contents. In T2 sequences, a thick hypointense ring around the lesion was noted
FIGURE 1. Preoperative and postoperative view of the patient. Ptosis and inferior vertical dystopia of the globe (left) as well as the scar of the brow incision at postoperative 1 month (right) are shown.
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery • Volume 26, Number 1, January 2015
FIGURE 2. Computed tomographic (A) and T2-weighted MRI (B) images show hyperintense and heterogenous supraorbital lesion in the well-aerated frontal sinus. C, Postoperative T2-weighted MRI at the 12-month follow-up.
(Fig. 2). The patient underwent an osteoplastic frontal sinus surgery through a left brow incision. Caldwell view radiograph of the patient was trimmed and sterilized as well as used as a template. A drill was used to create osteotomies, and osteoplastic flap was elevated. The left supraorbital lesion was exposed. The anterior and middle part of the orbital roof had been eroded, and the cyst wall adhered tightly to the periorbit. The bone in the superotemporal orbital area was substantially destroyed by the tumor, but orbital rim was intact. The viscous yellowish content was aspirated, pseudocapsule was curetted, cyst wall adhered to the periorbit was removed by sharp dissection as far as possible, and surrounding intact bone was scarified by using drill. The operative field was closed in a routine fashion, and fat obliteration of the frontal sinus was not performed. Histopathologic examination revealed numerous cholesterol clefts surrounded by granulomatous inflammation containing giant cells with hemosiderin deposition, which confirmed cholesterol granuloma (Fig. 3). The next day of the operation, the ocular movement and inferior displacement of his left eye were improved. However, the globe had completely returned to the normal position 2 weeks later. Magnetic resonance imaging evaluation showed no recurrence at the 12-month follow-up (Fig. 2C).
Brief Clinical Studies
hemosiderin, within a fibrous connective tissue, characterizes a cholesterol granuloma.6 The definitive management of cholesterol granuloma is drainage of the content, curettage or total removal of the cyst wall, and drilling of the tumor bed and surrounding intact bone.9 Surgical approaches to orbital tumors depend on tumoral relationships, size, location, goal of the surgery (biopsy or total excision), and possible nature of the lesion. In general, anterior lesions are treated via transorbital approaches, whereas lesions of the posterior third are best managed via extraorbital approaches. The anterior and lateral orbitotomies are the most preferred approaches to superolateral extraconal orbital lesions.10–12 Transcranial approach targets intraorbital lesions through the roof and lateral walls of the orbit. This approach is ideally suited for apical and superior orbital fissure lesions.12 In our case, pneumosinus dilatans was diagnosed through computed tomography. Pneumosinus dilatans is an abnormal enlargement of the sinus with extension beyond the normal boundaries of the bone.13 In the current case, pneumatization of the frontal sinus was extended to the supraorbital region and orbital roof because of pneumosinus dilatans. Frontal bossing and prominence of the supraorbital ridge were observed because of outward expansion of the sinus as well. Therefore, the frontal sinus osteoplastic approach was preferred. Contrary to the anterior orbitotomy approach, osteoplastic flap provided wide exposure without retracting the orbit in this case. The rationale for our proposed method of surgical management is that, if the frontal sinus pneumatization extends through the supraorbital region and orbital roof, osteoplastic flap approach provides wide exposure for supraorbital lesions.
REFERENCES
DISCUSSION Orbitofrontal cholesterol granuloma is a rare entity that is most frequently observed in middle-aged men and typically occurs within the frontal bone overlying the lacrimal fossa. The most common presenting symptoms are inferomedial displacement of the globe and proptosis.3 Diagnosis is based on radiologic imaging findings, which are paramount in the preoperative evaluation and differential diagnosis of cholesterol granuloma. Computed tomography usually shows an osteolytic extraconal lesion in the superolateral orbit. Magnetic resonance imaging can be of most value in the diagnosis of cholesterol granuloma and typically shows high signal intensity on both T1- and T2-weighted images owing to the its high lipid cholesterol content. The differential diagnosis of orbitofrontal cholesterol granuloma includes lacrimal gland neoplasms, metastatic tumors, aneurysmal bone cysts, epidermoid cysts, and mucoceles.7,8 The pathogenesis of cholesterol granuloma is stil unclear. Several possible mechanisms of pathogenesis have been suggested, including the obstruction-vacuum theory and exposed marrow theory.4,5 Hemorrhages into a bony cavity with hemolysis may lead to cholesterol precipitation. Microscopically, the encompassing of cholesterol clefts by foreign body giant cells in the presence of
FIGURE 3. Cholesterol clefts surrounded by granulomatous inflammation containing giant cells with hemosiderin deposition (hematoxylin-eosin stain).
1. McNab AA, Wright JE. Orbitofrontal cholesterol granuloma. Ophthalmology 1990;97:28–32 2. Ochiai H, Yamakawa Y, Fukushima T, et al. Large cholesterol granuloma arising from the frontal sinus: case report. Neurol Med Chir (Tokyo) 2001;41:283–287 3. Sia Dl, Davis G, Selva D. Recurrent orbitofrontal cholesterol granuloma: case report. Orbit 2012;31:184–186 4. Selva D, Phipps SE, O'Connell JX, et al. Pathogenesis of orbital cholesterol granuloma. Clin Experiment Ophthalmol 2003; 31:78–82 5. Jackler RK, Cho M. A new theory to explain the genesis of petrous apex cholesterol granuloma. Otol Neurotol 2003;24:96–106 6. Ko MT, Hwang CF, Kao YF, et al. Cholesterol granuloma of the maxillary sinus presenting as sinonasal polyp. Am J Otolaryngol 2006;27:370–372 7. Chow LP, McNab AA. Orbitofrontal cholesterol granuloma. J Clin Neurosci 2005;12:206–209 8. Arat YO, Chaudhry IA, Boniuk M. Orbitofrontal cholesterol granuloma: distinct diagnostic features and management. Ophthal Plast Reconstr Surg 2003;19:382–387 9. Aferzon M, Millman B, O'Donnell TR, et al. Cholesterol granuloma of the frontal bone. Otolaryngol Head Neck Surg 2002;127: 578–581 10. Okay O, Daglioglu E, Akdemir G, et al. Lateral orbitotomy approach to orbital tumors: report of 10 cases. Turk Neurosurg 2010;20:167–172 11. Prabhakaran VC, Hsuan J, Selva D. Endoscopic-assisted removal of orbital roof lesions via a skin crease approach. Skull Base 2007;17:341–345 12. Bejjani GK, Cockerham KP, Kennerdel JS, et al. A reappraisal of surgery for orbital tumors. Part I: extraorbital approaches. Neurosurg Focus 2001;10:E2 13. Desai NS, Sabo SS, Khandelwal A, et al. Pneumosinus dilatans: is it more than an aesthetic concern? J Craniofac Surg 2014;25:418–421
© 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
e37
