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A case of benign cementoblastoma
A case of benign cementoblastoma Shuichi Fujita, D.D.S., * Hiroshi Takahashi, D.D.S, Dr.Med.Sc..** Haruo Okabe, M.D.,*** Chiaki Watanabe, D.D.S,**** and Hidetoshi Sonobe, D.D.S., Dr.D.Sc.,**** Nagasaki and Mite, Japan NAGASAKI
UNIVERSITY
SCHOOL
OF DENTISTRY
AND
NATIONAL
MIT0
HOSPITAL
A rare case of benign cementoblastoma is reported. Active cementoblasts adding cementoid tissue were observed histologically by means of specific staining for unmineralized matrix of hard tissue. A polarizing microscope and an x-ray diffractometer were used to clarify the cementum-like tissue of benign cementoblastoma. The collagen bundles of tumor tissue showed irregular and random arrangements under polarized light. The qualitative analysis revealed that the mineralized component was composed of low-crystalline hydroxylapatite. (ORAL &JRG thAL i%b &AL PATHOL 1989;~:~8)
B
enign cementoblastoma is a relatively rare odontogenic tumor affecting the jaws of young persons. Although it is occasionally difficult to distinguish this disorder from other fibro-osseous lesions of the jaws, benign cementoblastoma has characteristic radiographic and histologic appearances and is attached to the tooth roots. We present a case report of benign cementoblastoma and discuss the cementurn-like tissue of the tumor. CASE REPORT
In April 1985 a 17-year-old woman visited a dental clinic with a complaint of swelling of the right mandibular region. The lesion failed to improve in spite of root canal treatment of the first molar in the same region. Two months later she was seen for evaluation of dull pain and gradual expansion of the right mandible. An unusual radiographic image of the right mandible was found. She was referred to the Department of Maxillofacial and Oral Surgery of National Mito Hospital for treatment. A semispherical, demarcated hard mass, approximately 4 cm in diameter, was palpated in the buccal sulcus from the mesial portion of the second premolar to the mesial aspect of the second molar. The covering gingival mucosa showed some redness.The first molar had an opened pulp chamber and enlarged root canals from previous endodontic treatment, but the secondpremolar had a vital response *Assistant Doctor, Department of Oral Pathology, Nagasaki University School of Dentistry. **Associate Professor, Department of Oral Pathology, Nagasaki University School of Dentistry. ***Professor, Department of Oral Pathology, Nagasaki University School of Dentistry. ****Clinics of Maxillofacial and Oral Surgery, National Mito Hospital. 64
to the electrical pulp test. One submandibular lymph node was palpable without tenderness, and paresthesia was not present. Family history, full blood count, and serum biochemical examination did not contribute to an understanding of the patient’s condition. Radiographs showed a mottled, round mass in contact
with the rootsof the first molar. The lesionwasseparated from the surrounding mandibular bone by a narrow radiolucent line (Fig. 1). A clinical diagnosis of cementoma was made. In July 1985 the patient was again admitted becauseof worsening inflammatory symptoms and discharge of pus from the lingual gingival trough of the first molar. After the symptoms improved with treatment with antibiotic and antiinflammatory agents, enucleation was performed on August 5 with the patient under general anesthesia. Mucoperiosteal flaps on both buccal and lingual sides, from the lower right canine to the lower right second molar, were raised. An almost resorbed cortical plate and bony globular massattached to the rootsof the first molar were exposed at the region of the second premolar and the first molar. The calcified mass was removed with both teeth; it measured 26 X 28 X 33 mm. The resultant cavity was packed with gauze coated with antibiotic ointment. Postoperative healing progressedfavorably. MATERIAL AND METHODS
The extirpated material attached to the tooth roots was sliced in 5 mm sections, and soft radiographs were taken. For light microscopy, decalcified and paraffin-embedded sections were stained with hematoxylin and eosin. To examine unmineralized areas of the other tissue, Yoshiki’s osteoid matrix stain’ was used after reaction to cyanuric chloride and decalcification had occurred. Yoshiki’s osteoid matrix stain is a modified hematoxylin-eosin stain that can iden-
A case of benign cementoblastoma
Volume 68 Number 1
Fig. 2. Soft radiograph shows radial narrow radiopaque spokes.
Fig. 1. Demarcated right first molar.
of
round lesion involves mandibular
tify unmineralized matrix of hard tissue. The osteoid matrix stains more intensely red than mineralized bone does because of the eosinophilic product obtained by reaction to cyanuric chloride. A cracked surface of the tumor was observed with the scanning electron microscope. A polarizing microscope was used to identify a pattern of collagenous-bundle deposition within the hard tissue of this lesion. For the qualitative analysis, diffraction images of the powdered tumor tissue were made with x-ray diffractometer. RESULTS Histopathologic
arrangement
65
Fig. 3. Globular lesion invades dental pulp. Connection with tooth roots is noted (Hematoxylin and eosin stain.)
findings
A soft radiograph revealed narrow, radiopaque, radially arranged trabecular structures at the periphery of the massand resorbed tooth roots (Fig. 2). The tumorous mass invaded dental pulp and partially fused with tooth roots (Fig. 3). Microscopically, the mass was composed of cementum-like tissue with numerous irregular basophilic reversal lines and scanty cementoblastic cells (Fig. 4). Some stroma in the mass contained many dilated blood vessels and
trabeculae rimmed by a number of large polygonal cells regarded as cementoblasts. In other areas of stroma near the tooth roots, neutrophilic infiltration was observed. Resorption of the hard tissue by multinucleated giant cells presumed to be cementoclasts was also noticed. These histologic findings indicated that the lesion was a typical benign cementoblastoma.
66
Fujita et al.
ORAL SURG ORAL
MED ORAL PATHOL July 1989
Fig. 4. Cementum-like tissue including numerous reversal lines. (Hematoxylin and eosin stain. Original magnification, X 190.)
Fig. 5. Trabecular structures rimmed by cementoblasts at edgeof tumor. Osteoid matrix shows a different staining quality from that of adjacent well-calcified area. (Yoshiki’s stain. Original magnification, X50.)
Fig. 6. Central portion of tumor. Calcified cementum-like tissue is bordered by unmineralized matrix. (Yoshiki’s stain. Original magnification, X85.)
Volume
A case of benign cementoblastoma
68
Number I
67
Fig. 7. Cracked surface shows collagen bundles with poor mineralization.
Yoshiki’s osteoid matrix stain demonstrated unmineralized matrix rimmed by cementoblasts in the interior portion as well as at the peripherally located radial trabeculae (Figs. 5 and 6). Scanning electron microscopy showed that the peripheral trabecular structures consisted of fiber bundles extending longitudinally; these bundles were considered to be poorly mineralized collagen fibers (Fig. 7). Polarizing microscopy demonstrated radiated, somewhat irregular, and narrow collagen bundles with intense birefrigence at the periphery and complicated birefrigence in the interior portion (Fig. 8). Qualitative
analysis.
The diffraction image of the tumor showed a broad curve. Comparison of calculated interplanar spacing based on Bragg’s formula with the Joint Committee on Powder Diffraction Standard card identified the interplanar spacing of this specimen as intense peaks of hydroxylapatite (Ca5(P0&0H). This finding suggested that the tumorous hard tissue consisted of low-crystalline hydroxylapatite (Fig. 9). DISCUSSION
In 1971 the World Health Organization2 (WHO) classified cementomas into four subdivisions: benign
Fig. 8. Complicated and narrow collagen bundles under polarized light. (Hematoxylin and eosin stain. Original magnification, X85.)
cementoblastoma, cementifying fibroma, periapical cemental dysplasia, and gigantiform cementoma; the WHO also indicated criteria for clinicopathologic diagnosis. The site predilection of benign cementoblastoma is the mandibular premolar and molar area, especially the first molar region.3 Benign cementoblastoma usually occurs in young persons less than 25 years of age and is more common in males than females.4*5 However, Farman and coworkers3and Makek and Lello6 stated that gender predilection was not statistically significant. Clinically, principal symptoms are swelling and slight pain. Serious symptoms suggestiveof malignancy are not described in literature expect for the reports of a recurrent case by Langdon’ and Esguep and colleagues.* The characteristic radiographic features of benign cementoblastoma with mature calcified tissue include a mottled round mass connected with the tooth root and a narrow, radiolucent area demarcating the tumor from surrounding bone. WHO described benign cementoblastoma histologically as “a neoplasm characterized by formation of sheetsof cementum-like tissue and . . . unmineralized at the periphery of the mass or in the more active growth areas.“2 Results of the radiographic
68 Fujita et al.
Fig.
9.
X-ray
ORAL SURGORAL MED ORAL PATHOL July 1989
diffraction
image of benign cementoblastoma
indicates low-crystalline
hydroxylapatite
peaks.
and histologic examination of the present case corresponded with these findings. We studied the unmineralized area of the tumor by means of Yoshiki’s osteoid matrix stain. This method showed unmineralized trabeculae at the periphery of the tumor and immature cementum added by cementoblasts in the interior portion. Evidence of gradual growth and central remodeling phenomenon was indicated by deposition by cementoblasts and resorption by cementoclasts and formation of sheets of cementum-like tissue containing numerous reversal lines. Polarizing microscopy and qualitative analysis of benign cementoblastoma have been reported. Giansanti9 and Waldron and Giansanti’O observed by polarizing microscopy that in comparison to bone, cementum had a narrow width and a unique pattern of collagen-bundle formation. We also observed that the cementum-like tissue of the benign cementoblastoma had narrow and complicated collagen-bundle deposition, The results of the qualitative analysis performed with an x-ray diffractometer suggested that the calcified material in this case consisted of immature hydroxylapatite. In establishing the diagnosis of benign cementoblastoma, the most important aspect is the differential diagnosis and separation from benign osteoblastoma; this separation is important because of the histologic similarity between the hard tissue of benign cementoblastoma and that of bone. Indeed, polarization microscopy revealed that cementumlike tissue of the benign cementoblastoma had narrow and complicated collagen bundles, but it is questionable whether there is a clear difference between the cementum-like tissue of benign cementoblastoma and bone tissue of benign osteoblastoma. The difficulty of differential diagnosis of both lesions was stated earlier.“~‘* We consider that the only method of differential diagnosis is investiga-
tion of whether the tumor is connected with the tooth root, as previously mentioned.13 REFERENCES
1. Yoshiki S. A simple histological method for identification of osteoid matrix in decalcified bone. In: Takahashi H, ed. Handbook of bone morphometry. Niigata: Nishimura Co, 1983:61-6. 2. Pindborg JJ, Kramer IRH, Gorlin RJ. Histological typing of odontogenic tumors, jaw cyst, and allied lesions. Geneva: World Health Organization, 1971:31-4. 3. Farman AG, Kohler WW, Nortje CJ, Van Wyk CW. Cementoblastoma: report of case. J Oral Surg 1979;37:198203. 4. Astacio JN, Mendez JE. Benign cementoblastoma (true
cementoma). ORAL SURG ORAL MED ORAL PATHOL 1974;38:95-9. 5. Anneroth G, IsacssonG, Singurdsson A. Benign cementoblastoma (true cementoma). ORAL SURG ORAL MED ORAL PATHOL1975;40:141-6. 6. Makek M, Lello G. Benign cementoblastoma: case report and literature review. J Maxillofac Surg 1982;10:182-6. how 7. Langdon JD. The benign cementoblastoma-just benign? Br J Oral Surg 1976;13:239-49. 8. Esguep A, Belvederessi M, Alfaro C. Benign cementoblastoma (report of an atypical case). J Oral Med 1983;38:99102. 9. Giansanti JS. The pattern and width of the collagen bundles in bone and cementum. ORALSURGORALMED ORALPATHOL 1970;30:508-14. 10. Waldron CA, Giansanti JS. Benign fibro-osseous lesions of the jaws: a clinical-radiologic-histologic review of sixty-five cases. ORAL SURGORAL MED ORAL PATHOL1973;35:34050.
11. Larsson A, Forsberg 0, Sjogren S. Benign cementoblastoma+ementum analogue of benign osteoblastoma. J Oral Surg 1978;36:299-303. 12. Monks FT, Bradley JC, Turner EP. Central osteoblastoma or cementoblastoma? A case report and 12 year review. Br J Oral Surg 1981;19:29-37. 13. Greer RD Jr, Berman DN. Osteoblastoma of the jaws: current concepts and differential diagnosis. J Oral Surg 1978;36:304-7. Reprint requests to:
Dr. S. Fujita, Department of Oral Pathology Nagasaki University School of Dentistry 7- 1, Sakamoto-machi Nagasaki 852, Japan
UNIVERSITY
SCHOOL
OF DENTISTRY
AND
NATIONAL
MIT0
HOSPITAL
A rare case of benign cementoblastoma is reported. Active cementoblasts adding cementoid tissue were observed histologically by means of specific staining for unmineralized matrix of hard tissue. A polarizing microscope and an x-ray diffractometer were used to clarify the cementum-like tissue of benign cementoblastoma. The collagen bundles of tumor tissue showed irregular and random arrangements under polarized light. The qualitative analysis revealed that the mineralized component was composed of low-crystalline hydroxylapatite. (ORAL &JRG thAL i%b &AL PATHOL 1989;~:~8)
B
enign cementoblastoma is a relatively rare odontogenic tumor affecting the jaws of young persons. Although it is occasionally difficult to distinguish this disorder from other fibro-osseous lesions of the jaws, benign cementoblastoma has characteristic radiographic and histologic appearances and is attached to the tooth roots. We present a case report of benign cementoblastoma and discuss the cementurn-like tissue of the tumor. CASE REPORT
In April 1985 a 17-year-old woman visited a dental clinic with a complaint of swelling of the right mandibular region. The lesion failed to improve in spite of root canal treatment of the first molar in the same region. Two months later she was seen for evaluation of dull pain and gradual expansion of the right mandible. An unusual radiographic image of the right mandible was found. She was referred to the Department of Maxillofacial and Oral Surgery of National Mito Hospital for treatment. A semispherical, demarcated hard mass, approximately 4 cm in diameter, was palpated in the buccal sulcus from the mesial portion of the second premolar to the mesial aspect of the second molar. The covering gingival mucosa showed some redness.The first molar had an opened pulp chamber and enlarged root canals from previous endodontic treatment, but the secondpremolar had a vital response *Assistant Doctor, Department of Oral Pathology, Nagasaki University School of Dentistry. **Associate Professor, Department of Oral Pathology, Nagasaki University School of Dentistry. ***Professor, Department of Oral Pathology, Nagasaki University School of Dentistry. ****Clinics of Maxillofacial and Oral Surgery, National Mito Hospital. 64
to the electrical pulp test. One submandibular lymph node was palpable without tenderness, and paresthesia was not present. Family history, full blood count, and serum biochemical examination did not contribute to an understanding of the patient’s condition. Radiographs showed a mottled, round mass in contact
with the rootsof the first molar. The lesionwasseparated from the surrounding mandibular bone by a narrow radiolucent line (Fig. 1). A clinical diagnosis of cementoma was made. In July 1985 the patient was again admitted becauseof worsening inflammatory symptoms and discharge of pus from the lingual gingival trough of the first molar. After the symptoms improved with treatment with antibiotic and antiinflammatory agents, enucleation was performed on August 5 with the patient under general anesthesia. Mucoperiosteal flaps on both buccal and lingual sides, from the lower right canine to the lower right second molar, were raised. An almost resorbed cortical plate and bony globular massattached to the rootsof the first molar were exposed at the region of the second premolar and the first molar. The calcified mass was removed with both teeth; it measured 26 X 28 X 33 mm. The resultant cavity was packed with gauze coated with antibiotic ointment. Postoperative healing progressedfavorably. MATERIAL AND METHODS
The extirpated material attached to the tooth roots was sliced in 5 mm sections, and soft radiographs were taken. For light microscopy, decalcified and paraffin-embedded sections were stained with hematoxylin and eosin. To examine unmineralized areas of the other tissue, Yoshiki’s osteoid matrix stain’ was used after reaction to cyanuric chloride and decalcification had occurred. Yoshiki’s osteoid matrix stain is a modified hematoxylin-eosin stain that can iden-
A case of benign cementoblastoma
Volume 68 Number 1
Fig. 2. Soft radiograph shows radial narrow radiopaque spokes.
Fig. 1. Demarcated right first molar.
of
round lesion involves mandibular
tify unmineralized matrix of hard tissue. The osteoid matrix stains more intensely red than mineralized bone does because of the eosinophilic product obtained by reaction to cyanuric chloride. A cracked surface of the tumor was observed with the scanning electron microscope. A polarizing microscope was used to identify a pattern of collagenous-bundle deposition within the hard tissue of this lesion. For the qualitative analysis, diffraction images of the powdered tumor tissue were made with x-ray diffractometer. RESULTS Histopathologic
arrangement
65
Fig. 3. Globular lesion invades dental pulp. Connection with tooth roots is noted (Hematoxylin and eosin stain.)
findings
A soft radiograph revealed narrow, radiopaque, radially arranged trabecular structures at the periphery of the massand resorbed tooth roots (Fig. 2). The tumorous mass invaded dental pulp and partially fused with tooth roots (Fig. 3). Microscopically, the mass was composed of cementum-like tissue with numerous irregular basophilic reversal lines and scanty cementoblastic cells (Fig. 4). Some stroma in the mass contained many dilated blood vessels and
trabeculae rimmed by a number of large polygonal cells regarded as cementoblasts. In other areas of stroma near the tooth roots, neutrophilic infiltration was observed. Resorption of the hard tissue by multinucleated giant cells presumed to be cementoclasts was also noticed. These histologic findings indicated that the lesion was a typical benign cementoblastoma.
66
Fujita et al.
ORAL SURG ORAL
MED ORAL PATHOL July 1989
Fig. 4. Cementum-like tissue including numerous reversal lines. (Hematoxylin and eosin stain. Original magnification, X 190.)
Fig. 5. Trabecular structures rimmed by cementoblasts at edgeof tumor. Osteoid matrix shows a different staining quality from that of adjacent well-calcified area. (Yoshiki’s stain. Original magnification, X50.)
Fig. 6. Central portion of tumor. Calcified cementum-like tissue is bordered by unmineralized matrix. (Yoshiki’s stain. Original magnification, X85.)
Volume
A case of benign cementoblastoma
68
Number I
67
Fig. 7. Cracked surface shows collagen bundles with poor mineralization.
Yoshiki’s osteoid matrix stain demonstrated unmineralized matrix rimmed by cementoblasts in the interior portion as well as at the peripherally located radial trabeculae (Figs. 5 and 6). Scanning electron microscopy showed that the peripheral trabecular structures consisted of fiber bundles extending longitudinally; these bundles were considered to be poorly mineralized collagen fibers (Fig. 7). Polarizing microscopy demonstrated radiated, somewhat irregular, and narrow collagen bundles with intense birefrigence at the periphery and complicated birefrigence in the interior portion (Fig. 8). Qualitative
analysis.
The diffraction image of the tumor showed a broad curve. Comparison of calculated interplanar spacing based on Bragg’s formula with the Joint Committee on Powder Diffraction Standard card identified the interplanar spacing of this specimen as intense peaks of hydroxylapatite (Ca5(P0&0H). This finding suggested that the tumorous hard tissue consisted of low-crystalline hydroxylapatite (Fig. 9). DISCUSSION
In 1971 the World Health Organization2 (WHO) classified cementomas into four subdivisions: benign
Fig. 8. Complicated and narrow collagen bundles under polarized light. (Hematoxylin and eosin stain. Original magnification, X85.)
cementoblastoma, cementifying fibroma, periapical cemental dysplasia, and gigantiform cementoma; the WHO also indicated criteria for clinicopathologic diagnosis. The site predilection of benign cementoblastoma is the mandibular premolar and molar area, especially the first molar region.3 Benign cementoblastoma usually occurs in young persons less than 25 years of age and is more common in males than females.4*5 However, Farman and coworkers3and Makek and Lello6 stated that gender predilection was not statistically significant. Clinically, principal symptoms are swelling and slight pain. Serious symptoms suggestiveof malignancy are not described in literature expect for the reports of a recurrent case by Langdon’ and Esguep and colleagues.* The characteristic radiographic features of benign cementoblastoma with mature calcified tissue include a mottled round mass connected with the tooth root and a narrow, radiolucent area demarcating the tumor from surrounding bone. WHO described benign cementoblastoma histologically as “a neoplasm characterized by formation of sheetsof cementum-like tissue and . . . unmineralized at the periphery of the mass or in the more active growth areas.“2 Results of the radiographic
68 Fujita et al.
Fig.
9.
X-ray
ORAL SURGORAL MED ORAL PATHOL July 1989
diffraction
image of benign cementoblastoma
indicates low-crystalline
hydroxylapatite
peaks.
and histologic examination of the present case corresponded with these findings. We studied the unmineralized area of the tumor by means of Yoshiki’s osteoid matrix stain. This method showed unmineralized trabeculae at the periphery of the tumor and immature cementum added by cementoblasts in the interior portion. Evidence of gradual growth and central remodeling phenomenon was indicated by deposition by cementoblasts and resorption by cementoclasts and formation of sheets of cementum-like tissue containing numerous reversal lines. Polarizing microscopy and qualitative analysis of benign cementoblastoma have been reported. Giansanti9 and Waldron and Giansanti’O observed by polarizing microscopy that in comparison to bone, cementum had a narrow width and a unique pattern of collagen-bundle formation. We also observed that the cementum-like tissue of the benign cementoblastoma had narrow and complicated collagen-bundle deposition, The results of the qualitative analysis performed with an x-ray diffractometer suggested that the calcified material in this case consisted of immature hydroxylapatite. In establishing the diagnosis of benign cementoblastoma, the most important aspect is the differential diagnosis and separation from benign osteoblastoma; this separation is important because of the histologic similarity between the hard tissue of benign cementoblastoma and that of bone. Indeed, polarization microscopy revealed that cementumlike tissue of the benign cementoblastoma had narrow and complicated collagen bundles, but it is questionable whether there is a clear difference between the cementum-like tissue of benign cementoblastoma and bone tissue of benign osteoblastoma. The difficulty of differential diagnosis of both lesions was stated earlier.“~‘* We consider that the only method of differential diagnosis is investiga-
tion of whether the tumor is connected with the tooth root, as previously mentioned.13 REFERENCES
1. Yoshiki S. A simple histological method for identification of osteoid matrix in decalcified bone. In: Takahashi H, ed. Handbook of bone morphometry. Niigata: Nishimura Co, 1983:61-6. 2. Pindborg JJ, Kramer IRH, Gorlin RJ. Histological typing of odontogenic tumors, jaw cyst, and allied lesions. Geneva: World Health Organization, 1971:31-4. 3. Farman AG, Kohler WW, Nortje CJ, Van Wyk CW. Cementoblastoma: report of case. J Oral Surg 1979;37:198203. 4. Astacio JN, Mendez JE. Benign cementoblastoma (true
cementoma). ORAL SURG ORAL MED ORAL PATHOL 1974;38:95-9. 5. Anneroth G, IsacssonG, Singurdsson A. Benign cementoblastoma (true cementoma). ORAL SURG ORAL MED ORAL PATHOL1975;40:141-6. 6. Makek M, Lello G. Benign cementoblastoma: case report and literature review. J Maxillofac Surg 1982;10:182-6. how 7. Langdon JD. The benign cementoblastoma-just benign? Br J Oral Surg 1976;13:239-49. 8. Esguep A, Belvederessi M, Alfaro C. Benign cementoblastoma (report of an atypical case). J Oral Med 1983;38:99102. 9. Giansanti JS. The pattern and width of the collagen bundles in bone and cementum. ORALSURGORALMED ORALPATHOL 1970;30:508-14. 10. Waldron CA, Giansanti JS. Benign fibro-osseous lesions of the jaws: a clinical-radiologic-histologic review of sixty-five cases. ORAL SURGORAL MED ORAL PATHOL1973;35:34050.
11. Larsson A, Forsberg 0, Sjogren S. Benign cementoblastoma+ementum analogue of benign osteoblastoma. J Oral Surg 1978;36:299-303. 12. Monks FT, Bradley JC, Turner EP. Central osteoblastoma or cementoblastoma? A case report and 12 year review. Br J Oral Surg 1981;19:29-37. 13. Greer RD Jr, Berman DN. Osteoblastoma of the jaws: current concepts and differential diagnosis. J Oral Surg 1978;36:304-7. Reprint requests to:
Dr. S. Fujita, Department of Oral Pathology Nagasaki University School of Dentistry 7- 1, Sakamoto-machi Nagasaki 852, Japan