Original articles
Cementoblastoma and osteoblastoma: a comparison of histologic features
Pieter J. Slootweg Department ot Pathoiogy. University Hospitat, Utrecht, The Netherlands
Slootweg PJ: Cementoblastoma and osteoblastoma: a comparison of histologic features. J Oral Pathol Med 1992; 21: 385-389. Three cases of cementoblastoma (CB) and three cases of osteoblastoma (OB) were histologically compared. The aim ofthe study was to investigate whether CB and OB are different in other aspects than being connected with a tooth. CB ca.ses were the following: maxillary lesions in a 23-yr-old woman and a 22-yrold man and a mandibular lesion in a 28-yr-old man. In one case the tumor was fused to the roots of two teeth. Of the OB cases, one occurred in the mandible of a 27-yr-old man, one in the ankle of a 19-yr-old male and one in the thoracic vertebrae of a 27-yr-old man. Histologically, CB and OB had the same appearance including peripheral spiculac rimmed by swollen blasts. This histologic similarity between OB and C"B indicates that the diagnosis CB should not be made unless the lesion is connected with a tooth.
In 1971, cementoblastoma (CB) was dcfuied as: "a neoplasm characterized by the formation of sheets of cementumlike tissue which may contain a very large number of reversal lines and be unmineralized at the periphery of the mass or in the more active growth areas" (I). However, the difficulty in distinguishing CB from osteoblastoma (OB) was already briefly mentioned at that time. This differential diagnostic problem has since been the subject of several papers. Some advocated that CB can be distinguished from OB by its typical histologic features as peripheral radiating columns of mineralized material lined by a rim of unmiiieralized matrix and swollen cementoblasts (2 3) or the presence of a vascular center in OB that should be absent in CB (4). Others stress the continuity of lesional mineralized material with the root of Ihe involved tooth (5 8) although it is also argued that OB may secondarily become connected with a tooth (9). Still others preter to leave the problem unresolved, especially when the presumably involved tooth has been extracted before (10). In this paper, three cases of CB and three of OB are compared with the aim to analyze similarities and dissimilarities between both lesions.
Material and methods
Six patients form the basis of this study. Ca.ses 1, 2 and 3 were sent for consultation from elsewhere. Cases 4, 5 and 6 were from the files of the Department of Pathology, University Hospital at Utrecht. All of them had adequate histologic and. Cases 5 and 6 excepted, radiographic documentation. Results
Clinical data are summarized in Table 1. Radiographic features of the jaw lesions are illustrated in Figs. I 4. In Cases I .^ tumors were characterized by a central radiopacity. A peripheral radiolucent zone surrounded the entire lesion in Case 2. In Case 3 such a radiolucent rim only partly surrounded the lesion and in Case 1 a radiolucent rim was entirely lacking. In Case 4, the lesion was radiolucent with tiny central opacities. In Cases 1 3 , the lesion was continuous with the roots of the adjacent teeth that showed evidence of external resorption. In Case 3 the lesion involved the roots of two molar teeth whereas the third molar tooth was not continuous with the lesions but nevertheless showed external root resorption. In Case 4, the lesion was close to the 34 that had been
Key words: cementoblastoma: jaws, neoplasms: odontogenic tumors: osteoblastoma, P, J, Stootweg, Department of Pathology H04 312, University Hospital, Postbox 85500. 3508 GA Utrecht, The Netherlands Accepted for publication April 13, 1992
treated endodontically. The radiograph (Fig. 4) suggested resorption ofthe apical root area of the 34 but subsequent histologic examination of this tooth that had been removed together with the lesion failed to show evidence of resorption, the root shortening being due to a previous apicoectomy. The 35 was missing. In Case 3, macroscopic examination of the specimen confirmed the radiologically distinct demarcation of the lesion (F"ig. 5). Histopathologic findings were almost the same for all six cases. The lesions consisted of varying amounts of poorly cellular mineralized material exhibiting prominent reversal lines (Fig. 6). Sometimes this mineralized tissue formed large areas, at other sites it appeared as irregularly contoured trabeculae. At the periphery ofthe larger areas of mineralized material, there were spicules arranged in a radiating pattern f>erpendicular to the surface (Figs. 7-9). This feature was especially prominent at the periphery of the lesion but could also be detected in more central parts. At the surface of the mineralized masses, large hyperchromatic cells with ample cytoplasm were focally present: at other sites multinucleated osteoclast-Iikc giant cells were observed. The stromal areas consisted of loosely textured tissue and con-
386
SLOOTWEG
Table 1. Clinical data of reported patients Case No, Age Sex 1
5
23 28 22 27 19
6
27
2 3 4
V
M M M M M
Site Left maxilla Right mandible Right maxilla Left mandible Ankle, site unspecified Thoracic vertebrae
In slides from Cases 2 and 3, adjacent jaw bone was present. No fusion of jaw bone to the lesional mineralized material could be detected, an intervening area of connective tissue unvariably separating the lesion from its surroundings. In Case 3 root resorption was also evident at the distobuccal root of the 17 and the roots of the 18 that were separated from the lesion by bony trabeculae and an intact periodontal ligament (Figs. 11, 13).
tained many dilated thin-walled bloodvessels. Tiny hemorrhages could be focally observed. In Cases 1 3 , fusion of the mineralized lesional tissue to the focally resorbed cementum and dentin surfaces Discussion was present; in Case 3 to 16 as well as In Cases 1 3, lesions were fused to the 17 (Figs. 10, 11). In Patient 4, the lesion roots of the involved teeth that showed was separated from the adjacent root external resorption in varying degrees by an uninvolved periodontal ligament and histologically they were composed that apparently formed a barrier be- of mineralized masses with prominent tween tumor and tooth (Fig. 12). All reversal likes focally lined by swollen involved teeth contained viable nonin- cementoblasts or multinucleated osteoflamed pulps. Tiny fragments of lam- clasts and lying in a loosely vascular ellar bone were present in Case 1 and 3. stroma. Peripheral radiating columns of
mineralized material were also a consistent feature. Therefore histologically as well as radiologically they met the diagnostic criteria of a CB (1, 11). Cases 4-6, although histologically similar to Cases 1 3 were diagnosed as OB, in Case 4 because the lesion was not connected with a tooth whereas in Cases 5 and 6, the lesions occurred in the extragnatic skeleton were a diagnosis of CB obviously is out of sense. In Case 4, OB could be a debatable diagnosis as the possibility that the lesion was indeed attached to the root of the tooth that was missing from the involved jaw area cannot be ruled out. Cases 5 and 6 however provide unequivocal evidence that OB and CB may exhibit the same histotnorphology, including the peripheral radiating columns of mineralized material considered to be specific for CB (2, 3) but also observed in OB previously (12) and in the present cases 4-6. Could this mean that CB is indeed
A 1f^ Radiopaque mass attached to roots of 2X, Fig. 2. Case 2. Radiopaque mass fused to mesial root of 47 (right side ofthe radiograph), ftg. J. Ca.se 3, Radiograph of surgical specimen shows radiopaque mass attached to 16 and 17, Note that distal root of 17 and roots of 18 are not connected with radiopaque lesion but nevertheless show severe resorption. Fig. 4. Case 4. Radiolucent lesion with some tiny radtopacities partly surrounds root of 34, 35 is missing.
Cementohlastonta \erstis osteohtastonia 387 nothing else than an OB fused to the root of a teeth as assumed before (13)? This is unlikely as OB's have been reported to occur in the tooth-bearing area of the jaw (14, 15) and it is difficult to understand why tumors occurring at the same location and with the same histology show this different behavior
unless assuming that they have a different nature. This different nature is not exemplified by histologic appearance which may be the same for OB and CB. Neither is it exempliftcd by the ability of CB to cause root resorption as root resorption may be due to pressure exerted
by expansively growing intraosseous jaw tumors of varying histology. Cells of CB's are, however, unique in producing mineralized material that fuses with
,*^'
Fig. ?. Case 3, Bueeopalatal slices of surgieal specimen. Tumor surrounds resorbed roots of the 16 (upper row: sliees I 3 trom left to right), Mesiobuecal and palatal roots of 17 (upper row: slices 4 and 5) are al,so partly resorbed whereas in these sliees detiiarcation between lesion and adjacent jaw bone is clearly shown, Distobuccal root of 17 (lower row: slice 1 from left to right) and roots of 18 (lower row: sliees 2 4) are resorbed without being connected with tumor.
Fig. S. Case 5. Lesion consists of poorly eellular mineralized material that forms peripheral spiculae protruding into surrounding cellular stroma. Cellular areas are also present in spaces within the mineralized matrix. H & E ,
(•
t'Ig. 6. Case 6, Poorly cellular niinerali/ed material with prominent reversal lines and smooth contours, thus resembling cementum but nevertheless occurring at extragnathic site, H & i;, X 120.
Fig. 7, Case 4, Cellular strotna surrounds poorly cellular calcified cetnentum-like tissue, Perpetidietilar arranged tadiating spiculae are clearly displayed. H & K, x 120.
Fig. 9. Case 6. Features thought to be typical for CB, as are poorly cellular mineralized material, peripheral spiculae lined by swollen cells and outer cellular layer, are also present in this case of OB. H & E , x 120,
388
SL(X)TWEG
a tooth. This peculiar feature of CB cannot be explained by site of origin of CB, e.g. so close to the root surface that no intervening periodontal ligament is left to separate the lesion from the root surface but must be a property inherent to the lesion as is illustrated by the involvement of not only several roots of one
Fig. 10. Case .1. Tumor fused to partly resorbed roots of 16. H & E, x2.5.
tooth but also by the connection of one lesion with several teeth (7, 16-18, Case 3). From these cases it can be inferred that cells of CB indeed have the property to bypass the tissues that normally protect the tooth against ankylosis as
Fig. 12. Case 4. Lesion adjacent to periodontal ligament and cementum-covered root. There is no involvement of root surface. H & E, X 120.
they not only fuse with one single root at which they have originated but also are able to make contact with other roots subsequently. This contact of mineralized tumor product with the root is preceded by resorption as demonstrated by Case 3 in which the distobuccal root of the 17 and all roots of the 18 exhibited resorption but were not yet connected with the tumor. It is reasonable to assume that the functional differences between OB and CB are due to a different histogenesis, CB probably derived from cells of the inner dental follicle destined to become cementoblasts (19) and OB having osteoprogenitor cells occurring throughout the entire skeleton as source. It appears that the connection with the teeth is not a fortuitous event in a lesion that otherwisely would have been diagnosed as OB but the morphologic expression of a specific property of the cells that form CB. Therefore the diagnostic designation cementoblastoma is justified, but only for those ca.ses in which this specific property is brought to expression. This means that the difference between cementoblastoma and osteoblastoma indeed depends on whether the lesion is fused to a tooth or not. Acknowledgemenl.i I express my appreciation to the following colleagues for contributing ca.se material to this study. Case I: Dr. R. A. I. 1)1- Vos and D r J. WIRDS, Knschede.
Case 2: Dr. P. J. J. G(K)RIS, Breda. Case 3: Dr. J. W. R. MFYHR, Arnhem and Dr. P. VAN STRIJEN, Bennekom.
References 1. PiNi)H()R
Cementoblastoma and osteoblastoma: a comparison of histologic features
Pieter J. Slootweg Department ot Pathoiogy. University Hospitat, Utrecht, The Netherlands
Slootweg PJ: Cementoblastoma and osteoblastoma: a comparison of histologic features. J Oral Pathol Med 1992; 21: 385-389. Three cases of cementoblastoma (CB) and three cases of osteoblastoma (OB) were histologically compared. The aim ofthe study was to investigate whether CB and OB are different in other aspects than being connected with a tooth. CB ca.ses were the following: maxillary lesions in a 23-yr-old woman and a 22-yrold man and a mandibular lesion in a 28-yr-old man. In one case the tumor was fused to the roots of two teeth. Of the OB cases, one occurred in the mandible of a 27-yr-old man, one in the ankle of a 19-yr-old male and one in the thoracic vertebrae of a 27-yr-old man. Histologically, CB and OB had the same appearance including peripheral spiculac rimmed by swollen blasts. This histologic similarity between OB and C"B indicates that the diagnosis CB should not be made unless the lesion is connected with a tooth.
In 1971, cementoblastoma (CB) was dcfuied as: "a neoplasm characterized by the formation of sheets of cementumlike tissue which may contain a very large number of reversal lines and be unmineralized at the periphery of the mass or in the more active growth areas" (I). However, the difficulty in distinguishing CB from osteoblastoma (OB) was already briefly mentioned at that time. This differential diagnostic problem has since been the subject of several papers. Some advocated that CB can be distinguished from OB by its typical histologic features as peripheral radiating columns of mineralized material lined by a rim of unmiiieralized matrix and swollen cementoblasts (2 3) or the presence of a vascular center in OB that should be absent in CB (4). Others stress the continuity of lesional mineralized material with the root of Ihe involved tooth (5 8) although it is also argued that OB may secondarily become connected with a tooth (9). Still others preter to leave the problem unresolved, especially when the presumably involved tooth has been extracted before (10). In this paper, three cases of CB and three of OB are compared with the aim to analyze similarities and dissimilarities between both lesions.
Material and methods
Six patients form the basis of this study. Ca.ses 1, 2 and 3 were sent for consultation from elsewhere. Cases 4, 5 and 6 were from the files of the Department of Pathology, University Hospital at Utrecht. All of them had adequate histologic and. Cases 5 and 6 excepted, radiographic documentation. Results
Clinical data are summarized in Table 1. Radiographic features of the jaw lesions are illustrated in Figs. I 4. In Cases I .^ tumors were characterized by a central radiopacity. A peripheral radiolucent zone surrounded the entire lesion in Case 2. In Case 3 such a radiolucent rim only partly surrounded the lesion and in Case 1 a radiolucent rim was entirely lacking. In Case 4, the lesion was radiolucent with tiny central opacities. In Cases 1 3 , the lesion was continuous with the roots of the adjacent teeth that showed evidence of external resorption. In Case 3 the lesion involved the roots of two molar teeth whereas the third molar tooth was not continuous with the lesions but nevertheless showed external root resorption. In Case 4, the lesion was close to the 34 that had been
Key words: cementoblastoma: jaws, neoplasms: odontogenic tumors: osteoblastoma, P, J, Stootweg, Department of Pathology H04 312, University Hospital, Postbox 85500. 3508 GA Utrecht, The Netherlands Accepted for publication April 13, 1992
treated endodontically. The radiograph (Fig. 4) suggested resorption ofthe apical root area of the 34 but subsequent histologic examination of this tooth that had been removed together with the lesion failed to show evidence of resorption, the root shortening being due to a previous apicoectomy. The 35 was missing. In Case 3, macroscopic examination of the specimen confirmed the radiologically distinct demarcation of the lesion (F"ig. 5). Histopathologic findings were almost the same for all six cases. The lesions consisted of varying amounts of poorly cellular mineralized material exhibiting prominent reversal lines (Fig. 6). Sometimes this mineralized tissue formed large areas, at other sites it appeared as irregularly contoured trabeculae. At the periphery ofthe larger areas of mineralized material, there were spicules arranged in a radiating pattern f>erpendicular to the surface (Figs. 7-9). This feature was especially prominent at the periphery of the lesion but could also be detected in more central parts. At the surface of the mineralized masses, large hyperchromatic cells with ample cytoplasm were focally present: at other sites multinucleated osteoclast-Iikc giant cells were observed. The stromal areas consisted of loosely textured tissue and con-
386
SLOOTWEG
Table 1. Clinical data of reported patients Case No, Age Sex 1
5
23 28 22 27 19
6
27
2 3 4
V
M M M M M
Site Left maxilla Right mandible Right maxilla Left mandible Ankle, site unspecified Thoracic vertebrae
In slides from Cases 2 and 3, adjacent jaw bone was present. No fusion of jaw bone to the lesional mineralized material could be detected, an intervening area of connective tissue unvariably separating the lesion from its surroundings. In Case 3 root resorption was also evident at the distobuccal root of the 17 and the roots of the 18 that were separated from the lesion by bony trabeculae and an intact periodontal ligament (Figs. 11, 13).
tained many dilated thin-walled bloodvessels. Tiny hemorrhages could be focally observed. In Cases 1 3 , fusion of the mineralized lesional tissue to the focally resorbed cementum and dentin surfaces Discussion was present; in Case 3 to 16 as well as In Cases 1 3, lesions were fused to the 17 (Figs. 10, 11). In Patient 4, the lesion roots of the involved teeth that showed was separated from the adjacent root external resorption in varying degrees by an uninvolved periodontal ligament and histologically they were composed that apparently formed a barrier be- of mineralized masses with prominent tween tumor and tooth (Fig. 12). All reversal likes focally lined by swollen involved teeth contained viable nonin- cementoblasts or multinucleated osteoflamed pulps. Tiny fragments of lam- clasts and lying in a loosely vascular ellar bone were present in Case 1 and 3. stroma. Peripheral radiating columns of
mineralized material were also a consistent feature. Therefore histologically as well as radiologically they met the diagnostic criteria of a CB (1, 11). Cases 4-6, although histologically similar to Cases 1 3 were diagnosed as OB, in Case 4 because the lesion was not connected with a tooth whereas in Cases 5 and 6, the lesions occurred in the extragnatic skeleton were a diagnosis of CB obviously is out of sense. In Case 4, OB could be a debatable diagnosis as the possibility that the lesion was indeed attached to the root of the tooth that was missing from the involved jaw area cannot be ruled out. Cases 5 and 6 however provide unequivocal evidence that OB and CB may exhibit the same histotnorphology, including the peripheral radiating columns of mineralized material considered to be specific for CB (2, 3) but also observed in OB previously (12) and in the present cases 4-6. Could this mean that CB is indeed
A 1f^ Radiopaque mass attached to roots of 2X, Fig. 2. Case 2. Radiopaque mass fused to mesial root of 47 (right side ofthe radiograph), ftg. J. Ca.se 3, Radiograph of surgical specimen shows radiopaque mass attached to 16 and 17, Note that distal root of 17 and roots of 18 are not connected with radiopaque lesion but nevertheless show severe resorption. Fig. 4. Case 4. Radiolucent lesion with some tiny radtopacities partly surrounds root of 34, 35 is missing.
Cementohlastonta \erstis osteohtastonia 387 nothing else than an OB fused to the root of a teeth as assumed before (13)? This is unlikely as OB's have been reported to occur in the tooth-bearing area of the jaw (14, 15) and it is difficult to understand why tumors occurring at the same location and with the same histology show this different behavior
unless assuming that they have a different nature. This different nature is not exemplified by histologic appearance which may be the same for OB and CB. Neither is it exempliftcd by the ability of CB to cause root resorption as root resorption may be due to pressure exerted
by expansively growing intraosseous jaw tumors of varying histology. Cells of CB's are, however, unique in producing mineralized material that fuses with
,*^'
Fig. ?. Case 3, Bueeopalatal slices of surgieal specimen. Tumor surrounds resorbed roots of the 16 (upper row: sliees I 3 trom left to right), Mesiobuecal and palatal roots of 17 (upper row: slices 4 and 5) are al,so partly resorbed whereas in these sliees detiiarcation between lesion and adjacent jaw bone is clearly shown, Distobuccal root of 17 (lower row: slice 1 from left to right) and roots of 18 (lower row: sliees 2 4) are resorbed without being connected with tumor.
Fig. S. Case 5. Lesion consists of poorly eellular mineralized material that forms peripheral spiculae protruding into surrounding cellular stroma. Cellular areas are also present in spaces within the mineralized matrix. H & E ,
(•
t'Ig. 6. Case 6, Poorly cellular niinerali/ed material with prominent reversal lines and smooth contours, thus resembling cementum but nevertheless occurring at extragnathic site, H & i;, X 120.
Fig. 7, Case 4, Cellular strotna surrounds poorly cellular calcified cetnentum-like tissue, Perpetidietilar arranged tadiating spiculae are clearly displayed. H & K, x 120.
Fig. 9. Case 6. Features thought to be typical for CB, as are poorly cellular mineralized material, peripheral spiculae lined by swollen cells and outer cellular layer, are also present in this case of OB. H & E , x 120,
388
SL(X)TWEG
a tooth. This peculiar feature of CB cannot be explained by site of origin of CB, e.g. so close to the root surface that no intervening periodontal ligament is left to separate the lesion from the root surface but must be a property inherent to the lesion as is illustrated by the involvement of not only several roots of one
Fig. 10. Case .1. Tumor fused to partly resorbed roots of 16. H & E, x2.5.
tooth but also by the connection of one lesion with several teeth (7, 16-18, Case 3). From these cases it can be inferred that cells of CB indeed have the property to bypass the tissues that normally protect the tooth against ankylosis as
Fig. 12. Case 4. Lesion adjacent to periodontal ligament and cementum-covered root. There is no involvement of root surface. H & E, X 120.
they not only fuse with one single root at which they have originated but also are able to make contact with other roots subsequently. This contact of mineralized tumor product with the root is preceded by resorption as demonstrated by Case 3 in which the distobuccal root of the 17 and all roots of the 18 exhibited resorption but were not yet connected with the tumor. It is reasonable to assume that the functional differences between OB and CB are due to a different histogenesis, CB probably derived from cells of the inner dental follicle destined to become cementoblasts (19) and OB having osteoprogenitor cells occurring throughout the entire skeleton as source. It appears that the connection with the teeth is not a fortuitous event in a lesion that otherwisely would have been diagnosed as OB but the morphologic expression of a specific property of the cells that form CB. Therefore the diagnostic designation cementoblastoma is justified, but only for those ca.ses in which this specific property is brought to expression. This means that the difference between cementoblastoma and osteoblastoma indeed depends on whether the lesion is fused to a tooth or not. Acknowledgemenl.i I express my appreciation to the following colleagues for contributing ca.se material to this study. Case I: Dr. R. A. I. 1)1- Vos and D r J. WIRDS, Knschede.
Case 2: Dr. P. J. J. G(K)RIS, Breda. Case 3: Dr. J. W. R. MFYHR, Arnhem and Dr. P. VAN STRIJEN, Bennekom.
References 1. PiNi)H()R
