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Ultrastructual morphology of juvenile psammomatoid ossifying fibroma
Auris Nasus Larynx 39 (2012) 314–316
Contents lists available at SciVerse ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Ultrastructual morphology of juvenile psammomatoid ossifying fibroma Sutthiphol Ariyasathitman a, Atsunobu Tsunoda b,*, Takao Tokumaru b, Kou Kayamori c, Shinichi Hirooka d, Seiji Kishimoto a a
Department of Head & Neck surgery, Tokyo Medical and Dental University, Japan Department of Otolaryngology, Tokyo Medical and Dental University, Japan c Department of Diagnostic Oral Pathology, Tokyo Medical and Dental University, Japan d Department of Human Pathology, Tokyo Medical and Dental University, Japan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 20 December 2010 Accepted 29 July 2011 Available online 31 August 2011
We investigated the ultrastructural morphology of the hard tissue in a fibro-osseous lesion. Bone samples were obtained from a juvenile psammomatoid ossifying fibroma and were observed under a scanning electron microscope. The lesion had a spongy lamellar structure containing bony tissue. On histological examination, resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed. Scanning electron microscopy revealed the bony material to have a cribriform structure and to indicate resorption related to osteoclasts throughout the tumor. These characteristic findings revealed the presence of active bony reconstruction and destruction in this lesion. The spongy calcified structure observed by scanning electron microscopy expressed the characteristic ground glass appearance in computed tomography of this patient. This remarkable activation of osteoclasts may deeply relate to characteristic calcified structure in this lesion. Observation of hard tissue structure under a scanning electron microscope may shed light on the pathology of fibroosseous lesions in the head and neck. ß 2011 Elsevier Ireland Ltd. All rights reserved.
Keywords: Cathepsin K Computed tomography Magnetic resonance imaging Ossifying fibroma Osteoclasts Scanning electron microscopy
1. Introduction
2. Case report
Benign fibro-osseous lesions are among the rare diseases of the head and neck region [1]. These lesions, such as fibrous dysplasia and ossifying fibroma, overlap in terms of clinical, radiological, and histopathological findings. Juvenile psammomatoid ossifying fibroma is a subtype of aggressive ossifying fibroma and is an uncommon, benign neoplasm of bone that typically presents in children and adolescents [2,3]. These ossifying fibromas have two histopathological variants: psammamatous and trabecular. The former type mainly involves the bones of the orbit and paranasal sinuses and sometimes causes severe clinical problems. We present a case of psammomatoid ossifying fibroma and describe its ultrastructural bony pathology as observed by scanning electron microscopy (SEM).
A 10-year-old boy experienced nasal obstruction for one year. Epistaxis, diplopia, and proptosis occurred subsequently on the left side. He was sent to a regional hospital and a large, hemorrhagic nasal tumor was found. A biopsy was performed and an osteoma was diagnosed, after which the boy was referred to our hospital. Computed tomography (CT) showed a huge wellcircumscribed, round tumor occupying both sides of the nasal cavity and extending to the left orbit and anterior skull base (Fig. 1a). The lesion had a slightly heterogenous, ground glass appearance. Its density was low when compared with that of the cortical bones. T1- and T2-weighted magnetic resonance imaging (MRI) revealed slightly heterogenous, intermediate-to-high signal intensity (Fig. 1b). The patient underwent resection of the tumor by anterior skull base surgery under an anterior craniotomy with nasal endoscopic guidance. Macroscopic examination demonstrated a hemorrhagic tumor with a spongy and bony lamellar structure (Fig. 2a and b). The entire tumor was removed except for a tiny residual lesion contiguous to the optic canal. Ophthalmic symptoms subsided gradually after the surgery. On histological examination, the tumor tissues are composed of dense fibroblastic stroma containing many round basophilic cement-like ossificles resembling psammoma bodies (Fig. 3a).
* Corresponding author at: Department of Otolaryngology and Head and Neck Surgery, Tokyo Medical and Dental University, Bunkyo-ku, Yushima 1-5-45, Tokyo 113-8519, Japan. Fax: +81 3 3813 2134. E-mail addresses: [email protected], [email protected] (A. Tsunoda). 0385-8146/$ – see front matter ß 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.anl.2011.07.019
[(Fig._1)TD$IG]
S. Ariyasathitman et al. / Auris Nasus Larynx 39 (2012) 314–316
315
Fig. 1. Computed tomography (a) and magnetic resonance imaging (b) findings in this patient. Computed tomography shows a huge well-circumscribed, round tumor occupying both sides of the nasal cavity and extending to the left orbit and anterior skull base (a). This lesion shows a ground-glass-like appearance, which indicates a mixture of ossified and non-ossified segments. Fat suppression T1-weighted magnetic resonance imaging with gadolinium DTPA enhancement also shows this huge tumor. This lesion shows intermediate slightly heterogenous signal density compared with the cortical bone or brain (b).
Immunohistochemical analysis for cathepsin K using mouse anti-human monoclonal antibody was subsequently performed according to a previously reported method [4]. Osteoclasts were detected in the specimen, especially in the margin of the tumor tissue, and resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed (Fig. 3b). To observe the hard tissue structure, soft tissue was removed from the surgical specimen by 5% hydrochloride solution for 24 h. The specimen was then rinsed in water, dried thoroughly, and finally coated with gold at a 20-nm thickness by an ion coater. The morphology of the hard tissue structure was examined under a vacuum with a scanning electron microscope (SEM; Hitachi S-4500 cFEG SEM, Tokyo, Japan). On SEM observation, the tumor specimen showed a spongy osseous structure (Fig. 3c). In this osseous cribriform structure, resorption pits of various sizes that are related to osteoclasts were observed throughout the tumor (Fig. 3c and d). The cribriform structure was thought to have housed osteoclasts, fibroblast-like cells, and vessels. These findings seemed to indicate the presence of active bone destruction and formation in the tumor. Such a spongy calcified structure was also consistent with the preoperative CT and MRI findings. A diagnosis of juvenile psammomatoid ossifying fibroma was accordingly made.
[(Fig._2)TD$IG]
3. Discussion Various disorders such as inflammation, cysts, and benign and malignant tumors exhibit various patterns of bony lesions characterized by erosion, invasion, or destruction. These changes occurring in the bone are clinically quite different from each other; however, the microscopic and molecular mechanisms of bony changes are thought to be similar. In such lesions, osteoclasts play a major role in these osteolytic processes and activation of these cells is induced by a common mechanism: the RANK–RANKL pathway, which is also observed in both squamous cell carcinoma and cholesteatoma [4,5]. The ossifying fibroma is a relatively rare benign neoplasm that predominantly develops in the jaw [6]. This tumor shows characteristic bony pathology, although its etiology is still unclear. The juvenile ossifying fibroma is an aggressive variety of ossifying fibroma and shows a destructive nature. It sometimes causes severe clinical symptoms; however, it is identical to the routine ossifying fibroma consisting of fibrous tissue that contains various amounts of irregular bony trabeculae on histological findings. From the viewpoint of its characteristic findings, the bony pathology of an ossifying fibroma seems to be different from other common bone pathologies such as erosion. In this report, we used a different method of evaluating the bony lesion. First, we investigated this lesion by immunohistology.
Fig. 2. This hemorrhagic tumor consisted of multiple lamellar structures. This tumor could be peeled off using a nasal elevatorium (a). The lamellar specimen is soft and shows a spongy form (b).
[(Fig._3)TD$IG]
316
S. Ariyasathitman et al. / Auris Nasus Larynx 39 (2012) 314–316
Fig. 3. Histology of this specimen. The tumor tissues are composed of dense fibloblastic storma containing many round basophilic cement-like ossificles resembling psammoma bodies (a: HE 100). In the margin of the tumor tissue, resorbing preexsinting lamellar bone associated with a large number of cathepsin K positive osteoclasts (arrows) was confirmed (b: 100). On SEM, the tumor specimen showed a spongy, calcified structure (c: 130). This spongy calcification represents ground glass like appearance on image studies. Resorption pits (*) of various size, related to osteoclasts, are observed throughout the tumor (d: 1000).
Numerous cathepsin K-positive osteoclasts were observed in the margin of the tumor tissue. This reflects an actively growing destructive bony lesion of this tumor deeply related to the activation of the osteoclasts. In addition to this, we observed the calcified structure of this lesion by SEM. This method completely removes the proteins and nucleic acids and is not suitable for the investigation of molecular mechanisms. However, it does enable the precise evaluation of hard tissue, particularly structural changes in bone [7]. In the present case, the presence of numerous pits suggested increased osteoclast activity and was consistent with the findings obtained from immunohistology. The characteristic spongy calcified structure observed on SEM was also related to the radiological findings. The spongy bone was present in the medium density lesion with a slightly heterogenous, ground glass appearance on CT and medium signal intensity on both T1- and T2weighted MRI. The mechanism of the diffuse and remarkable activation of osteoclasts may deeply relate to the characteristic calcified structure in juvenile psammomatoid ossifying fibroma; however, the etiology of this distinct activation is still unclear. Further examination of the molecular mechanism of ossifying fibromas is necessary. However, our investigation may offer an insight into the pathological process of this disease. 4. Conclusion The ultrastructural morphology of the hard tissue of the juvenile psammomatoid ossifying fibroma is reported, with particular reference to the immunohistopathology and imaging findings.
The combination of this SEM technique with those of molecular histopathology has played an important role in the investigation of this bony lesion. Observation of the hard tissue structure under SEM may also shed light on the pathology of fibro-osseus lesions in the head and neck. Acknowledgement Authors greatly appreciated the cooperation of Dr. Shizuko Ichinose in scanning electron microscopy and also appreciated Drs. Ichiro Yamada, Kazuchika Ohno and Taro Fujikawa for manuscript preparation. References [1] Naresh K, Panda MS. A clinicoradiologic analysis of symptomatic craniofacial fibro-osseous lesions. Otolaryngol Head Neck Surg 2007;136:928–33. [2] Commins DJ, Tolley NS, Milford CA. Fibrous dysplasia and ossifying fibroma of the paranasal sinuses. J Laryngol Otol 1998;112:964–5. [3] Smith SF, Newman L, Walker DM, et al. Juvenile aggressive psammomatoid ossifying fibroma: an interesting, challenging, and unusual case report and review of the literature. J Oral Maxillofac Surg 2009;67:200–6. [4] Ishikuro M, Sakamoto K, Kayamori K, et al. Significance of the fibrous stroma in bone invasion by human gingival squamous cell carcinomas. Bone 2008;43:621–7. [5] Jeong J-H, Park C-W, Tae K, et al. Expression of RANKL and OPG in middle ear cholesteatoma tissue. Laryngoscope 2006;116:1180–4. [6] Weber AL, Scrivani SJ. Mandible: anatomy cysts, tumors, and nontumourous lesions. In: Som PM, Curtin HD, editors. Head and neck imaging. 3rd ed., St. Louis: Mosby; 1996. p. 319–49. [7] Tsunoda A, Terasaki O. Dehiscence of the bone in the middle cranial fossa over the superior semicircular canal. J Laryngol Otol 2002;116:514–8.
Contents lists available at SciVerse ScienceDirect
Auris Nasus Larynx journal homepage: www.elsevier.com/locate/anl
Ultrastructual morphology of juvenile psammomatoid ossifying fibroma Sutthiphol Ariyasathitman a, Atsunobu Tsunoda b,*, Takao Tokumaru b, Kou Kayamori c, Shinichi Hirooka d, Seiji Kishimoto a a
Department of Head & Neck surgery, Tokyo Medical and Dental University, Japan Department of Otolaryngology, Tokyo Medical and Dental University, Japan c Department of Diagnostic Oral Pathology, Tokyo Medical and Dental University, Japan d Department of Human Pathology, Tokyo Medical and Dental University, Japan b
A R T I C L E I N F O
A B S T R A C T
Article history: Received 20 December 2010 Accepted 29 July 2011 Available online 31 August 2011
We investigated the ultrastructural morphology of the hard tissue in a fibro-osseous lesion. Bone samples were obtained from a juvenile psammomatoid ossifying fibroma and were observed under a scanning electron microscope. The lesion had a spongy lamellar structure containing bony tissue. On histological examination, resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed. Scanning electron microscopy revealed the bony material to have a cribriform structure and to indicate resorption related to osteoclasts throughout the tumor. These characteristic findings revealed the presence of active bony reconstruction and destruction in this lesion. The spongy calcified structure observed by scanning electron microscopy expressed the characteristic ground glass appearance in computed tomography of this patient. This remarkable activation of osteoclasts may deeply relate to characteristic calcified structure in this lesion. Observation of hard tissue structure under a scanning electron microscope may shed light on the pathology of fibroosseous lesions in the head and neck. ß 2011 Elsevier Ireland Ltd. All rights reserved.
Keywords: Cathepsin K Computed tomography Magnetic resonance imaging Ossifying fibroma Osteoclasts Scanning electron microscopy
1. Introduction
2. Case report
Benign fibro-osseous lesions are among the rare diseases of the head and neck region [1]. These lesions, such as fibrous dysplasia and ossifying fibroma, overlap in terms of clinical, radiological, and histopathological findings. Juvenile psammomatoid ossifying fibroma is a subtype of aggressive ossifying fibroma and is an uncommon, benign neoplasm of bone that typically presents in children and adolescents [2,3]. These ossifying fibromas have two histopathological variants: psammamatous and trabecular. The former type mainly involves the bones of the orbit and paranasal sinuses and sometimes causes severe clinical problems. We present a case of psammomatoid ossifying fibroma and describe its ultrastructural bony pathology as observed by scanning electron microscopy (SEM).
A 10-year-old boy experienced nasal obstruction for one year. Epistaxis, diplopia, and proptosis occurred subsequently on the left side. He was sent to a regional hospital and a large, hemorrhagic nasal tumor was found. A biopsy was performed and an osteoma was diagnosed, after which the boy was referred to our hospital. Computed tomography (CT) showed a huge wellcircumscribed, round tumor occupying both sides of the nasal cavity and extending to the left orbit and anterior skull base (Fig. 1a). The lesion had a slightly heterogenous, ground glass appearance. Its density was low when compared with that of the cortical bones. T1- and T2-weighted magnetic resonance imaging (MRI) revealed slightly heterogenous, intermediate-to-high signal intensity (Fig. 1b). The patient underwent resection of the tumor by anterior skull base surgery under an anterior craniotomy with nasal endoscopic guidance. Macroscopic examination demonstrated a hemorrhagic tumor with a spongy and bony lamellar structure (Fig. 2a and b). The entire tumor was removed except for a tiny residual lesion contiguous to the optic canal. Ophthalmic symptoms subsided gradually after the surgery. On histological examination, the tumor tissues are composed of dense fibroblastic stroma containing many round basophilic cement-like ossificles resembling psammoma bodies (Fig. 3a).
* Corresponding author at: Department of Otolaryngology and Head and Neck Surgery, Tokyo Medical and Dental University, Bunkyo-ku, Yushima 1-5-45, Tokyo 113-8519, Japan. Fax: +81 3 3813 2134. E-mail addresses: [email protected], [email protected] (A. Tsunoda). 0385-8146/$ – see front matter ß 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.anl.2011.07.019
[(Fig._1)TD$IG]
S. Ariyasathitman et al. / Auris Nasus Larynx 39 (2012) 314–316
315
Fig. 1. Computed tomography (a) and magnetic resonance imaging (b) findings in this patient. Computed tomography shows a huge well-circumscribed, round tumor occupying both sides of the nasal cavity and extending to the left orbit and anterior skull base (a). This lesion shows a ground-glass-like appearance, which indicates a mixture of ossified and non-ossified segments. Fat suppression T1-weighted magnetic resonance imaging with gadolinium DTPA enhancement also shows this huge tumor. This lesion shows intermediate slightly heterogenous signal density compared with the cortical bone or brain (b).
Immunohistochemical analysis for cathepsin K using mouse anti-human monoclonal antibody was subsequently performed according to a previously reported method [4]. Osteoclasts were detected in the specimen, especially in the margin of the tumor tissue, and resorbing preexisting lamellar bone associated with a large number of cathepsin K-positive osteoclasts was confirmed (Fig. 3b). To observe the hard tissue structure, soft tissue was removed from the surgical specimen by 5% hydrochloride solution for 24 h. The specimen was then rinsed in water, dried thoroughly, and finally coated with gold at a 20-nm thickness by an ion coater. The morphology of the hard tissue structure was examined under a vacuum with a scanning electron microscope (SEM; Hitachi S-4500 cFEG SEM, Tokyo, Japan). On SEM observation, the tumor specimen showed a spongy osseous structure (Fig. 3c). In this osseous cribriform structure, resorption pits of various sizes that are related to osteoclasts were observed throughout the tumor (Fig. 3c and d). The cribriform structure was thought to have housed osteoclasts, fibroblast-like cells, and vessels. These findings seemed to indicate the presence of active bone destruction and formation in the tumor. Such a spongy calcified structure was also consistent with the preoperative CT and MRI findings. A diagnosis of juvenile psammomatoid ossifying fibroma was accordingly made.
[(Fig._2)TD$IG]
3. Discussion Various disorders such as inflammation, cysts, and benign and malignant tumors exhibit various patterns of bony lesions characterized by erosion, invasion, or destruction. These changes occurring in the bone are clinically quite different from each other; however, the microscopic and molecular mechanisms of bony changes are thought to be similar. In such lesions, osteoclasts play a major role in these osteolytic processes and activation of these cells is induced by a common mechanism: the RANK–RANKL pathway, which is also observed in both squamous cell carcinoma and cholesteatoma [4,5]. The ossifying fibroma is a relatively rare benign neoplasm that predominantly develops in the jaw [6]. This tumor shows characteristic bony pathology, although its etiology is still unclear. The juvenile ossifying fibroma is an aggressive variety of ossifying fibroma and shows a destructive nature. It sometimes causes severe clinical symptoms; however, it is identical to the routine ossifying fibroma consisting of fibrous tissue that contains various amounts of irregular bony trabeculae on histological findings. From the viewpoint of its characteristic findings, the bony pathology of an ossifying fibroma seems to be different from other common bone pathologies such as erosion. In this report, we used a different method of evaluating the bony lesion. First, we investigated this lesion by immunohistology.
Fig. 2. This hemorrhagic tumor consisted of multiple lamellar structures. This tumor could be peeled off using a nasal elevatorium (a). The lamellar specimen is soft and shows a spongy form (b).
[(Fig._3)TD$IG]
316
S. Ariyasathitman et al. / Auris Nasus Larynx 39 (2012) 314–316
Fig. 3. Histology of this specimen. The tumor tissues are composed of dense fibloblastic storma containing many round basophilic cement-like ossificles resembling psammoma bodies (a: HE 100). In the margin of the tumor tissue, resorbing preexsinting lamellar bone associated with a large number of cathepsin K positive osteoclasts (arrows) was confirmed (b: 100). On SEM, the tumor specimen showed a spongy, calcified structure (c: 130). This spongy calcification represents ground glass like appearance on image studies. Resorption pits (*) of various size, related to osteoclasts, are observed throughout the tumor (d: 1000).
Numerous cathepsin K-positive osteoclasts were observed in the margin of the tumor tissue. This reflects an actively growing destructive bony lesion of this tumor deeply related to the activation of the osteoclasts. In addition to this, we observed the calcified structure of this lesion by SEM. This method completely removes the proteins and nucleic acids and is not suitable for the investigation of molecular mechanisms. However, it does enable the precise evaluation of hard tissue, particularly structural changes in bone [7]. In the present case, the presence of numerous pits suggested increased osteoclast activity and was consistent with the findings obtained from immunohistology. The characteristic spongy calcified structure observed on SEM was also related to the radiological findings. The spongy bone was present in the medium density lesion with a slightly heterogenous, ground glass appearance on CT and medium signal intensity on both T1- and T2weighted MRI. The mechanism of the diffuse and remarkable activation of osteoclasts may deeply relate to the characteristic calcified structure in juvenile psammomatoid ossifying fibroma; however, the etiology of this distinct activation is still unclear. Further examination of the molecular mechanism of ossifying fibromas is necessary. However, our investigation may offer an insight into the pathological process of this disease. 4. Conclusion The ultrastructural morphology of the hard tissue of the juvenile psammomatoid ossifying fibroma is reported, with particular reference to the immunohistopathology and imaging findings.
The combination of this SEM technique with those of molecular histopathology has played an important role in the investigation of this bony lesion. Observation of the hard tissue structure under SEM may also shed light on the pathology of fibro-osseus lesions in the head and neck. Acknowledgement Authors greatly appreciated the cooperation of Dr. Shizuko Ichinose in scanning electron microscopy and also appreciated Drs. Ichiro Yamada, Kazuchika Ohno and Taro Fujikawa for manuscript preparation. References [1] Naresh K, Panda MS. A clinicoradiologic analysis of symptomatic craniofacial fibro-osseous lesions. Otolaryngol Head Neck Surg 2007;136:928–33. [2] Commins DJ, Tolley NS, Milford CA. Fibrous dysplasia and ossifying fibroma of the paranasal sinuses. J Laryngol Otol 1998;112:964–5. [3] Smith SF, Newman L, Walker DM, et al. Juvenile aggressive psammomatoid ossifying fibroma: an interesting, challenging, and unusual case report and review of the literature. J Oral Maxillofac Surg 2009;67:200–6. [4] Ishikuro M, Sakamoto K, Kayamori K, et al. Significance of the fibrous stroma in bone invasion by human gingival squamous cell carcinomas. Bone 2008;43:621–7. [5] Jeong J-H, Park C-W, Tae K, et al. Expression of RANKL and OPG in middle ear cholesteatoma tissue. Laryngoscope 2006;116:1180–4. [6] Weber AL, Scrivani SJ. Mandible: anatomy cysts, tumors, and nontumourous lesions. In: Som PM, Curtin HD, editors. Head and neck imaging. 3rd ed., St. Louis: Mosby; 1996. p. 319–49. [7] Tsunoda A, Terasaki O. Dehiscence of the bone in the middle cranial fossa over the superior semicircular canal. J Laryngol Otol 2002;116:514–8.