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Calcifying odontogenic cyst: A proposal for a more appropriate terminology and classification
021-C2 Pathology (cyst and others) & Trauma 021-C2 Pathology (cyst and others) & Trauma 1. Calcifying Odontogenic Cyst: A Proposal for a More Appropriate Terminology and Classification
Toida, M. Department of Oral Surg. & Oral ivied., Ibi General Hosp., Ibi/Gifu, Japan So-called calcifying 0dontogenic cyst (COC) shows an extensive diversity in its clinico-histopathological appearances and biological behaviors. Because of this diversity, there have been confusion and disagreement in the terminology, classification and subclassification of this lesion. Regarding the nature of COC, there have been two concepts, which are contradictory to each other. The first concept is the "monistic" one that all COCs are neoplastic in nature, even though most are cystic in architecture and appear to be nonneoplastic. The second is the "dualistic" concept that COC contains two entities: a cyst and a neoplasm. Although the World Health Organization (WHO) adopted the former concept in 1992, now it seems to be difficult to decide which of the two is appropriate. Therefore, based on the two concepts, the author proposes two new simple and basic classifications with several new terms for this lesion: the "monistic" classification and the "dualistic" one. In the "monistic" classification, a new term "calcifying odontogenic tumor (COT)" may be more appropriate to represent a neoplastic lesion than the familiar term "COC". If the "dualistic" concept is in fact true, the W H O classification (1992) should be revised. In the "dualistic" classification, the use of the term "COC" should be restricted to true cystic (non-iaeoplastic) entities, which should be classified as developmental odontogenic cysts. On the other hand, the neoplastic entities, which should be classified as benign odontogenic tumors, may be termed COT. In both of the two classifications, the COT, which may also be termed odontogenic ghost cell tumor (OGCT; WHO, 1992) or calcifying ghost cell odontogenic tumor (CGCOT; FEJE~SKOV & KROGI~, 1972), can be either cystic (cystic COT) or solid (solid COT) in architecture. The solid COT may also be termed dentinogenic ghost cell tumor (DGCT; PRAETORIUS et al., 1981) or epithelial odontogenic ghost cell tumor (EOGCT; ELLIS & SHMOOKLER, 1986).
2. The Relationship between Intracystie Fluid Pressure and Fluid Osmolality in Jaw Cysts
Kimura, H., Narita, A., Fukui, R. Department of Dentistry and Oral Surgery, Hirosaki Univ., Hirosaki, Japan It is well known that the increase in intracystic fluid pressure is an important factor in cyst enlargement accompanying pathological bone absorption. However, accurate data of the intracystic pressure and osmolality of cyst fluid in the same
55
patients has not been reported. Therefore, we measured both the intracystic fluid pressure (IFP) of jaw cysts and the colloid osmotic pressure (COP) of cyst fluids. On the basis of clinical and radiologic findings, 43 patients with jaw cysts were selected for I F P and COP measurement. According to the W H O classification, there were 11 cases of odontogenic cysts, 4 of non-odontogenic cysts, 16 of inflammatory cysts, and 12 of postoperative maxillary cysts. By puncturing under local anesthesia, I F P was directly measured with a pressure transducer. Just after I F P measurement, cyst fluid was aspirated to measure COP by a Colloid Osmometer (Wescor Co., USA). The mean value of maximal I F P was 30.8-+18.9 (SD) mmHg. That of COP was 24.4+13.3 mmHg. There was a weak and proportional correlation between I F P and COR Owing to the histological typing of jaw cysts, inflammatory cysts showed higher values of IFP and COP than odontogenic cysts. Some cases were treated with irrigation therapy, which replaced cyst fluid with physiological saline once a month. Jaw cysts treated with this therapy gradually decreased in size with corresponding declines of IFP and COR These results revealed that intracystic fluid pressure was closely related to the colloid osmolality of cyst fluid and that the increase in intracystic pressure was induced by the inflammation of cyst wall tissues. The findings also suggested that microvascular injury was responsible for bone absorption in jaw cysts.
3. Blandin-Nuhn Cysts: Report of Six Cases
Tamaki, H., Taniguchi, S., Kondo, S., Watanabe, K., Kato, K., Yasuda, J.-L Department of Dentistry and Oral Surgery, Nagoya National Hospital, Nagoya, Japan Blandin-Nuhn cyst, which is a comparatively rare mucocele occurring in anterior lingual salivary glands, has been reported to clinico-statistically represent ca. 10% of salivary gland-originating mucous cysts. Having experienced 6 cases of this cyst, we would like to report the outline of their clinical and histological examinations. Salivary gland-originating mucous cysts, as treated by our department during the past 11 years totaled 84, of which 8.3% were represented by Blandin-Nuhn cyst. For the above 6 cases of Blandin-Nuhn cysts, the ratio of incidence by sexes was 1:2 with female predominance and the age distribution ranged from 7 to 15 years with 3 cases below 10 and 3 teenage cases (averaging 10.7). Cysts protruded extraversively from the mucosal surface and were hemispherical oval. Cyst diameter was 3 and 12 mm minimally and maximally, respectively, being under 10 mm in most cases. These 6 patients were suffering from illness for ~ 8 weeks, averaging 4. Only one patient had a past history of traumatism and a description of bad habits. Preoperative diagnosis was mucous cyst in 5 cases and lingual tumor in one case, with the diagnostic efficacy being high. The treatment was always made via resection, without any case of postoperative relapse. The histological diagnosis was extravasation type mucous cyst in all cases. Atrophic acinus and inflammatory granulation tissue were observed in all cases. Formation of an obvious cystic
Toida, M. Department of Oral Surg. & Oral ivied., Ibi General Hosp., Ibi/Gifu, Japan So-called calcifying 0dontogenic cyst (COC) shows an extensive diversity in its clinico-histopathological appearances and biological behaviors. Because of this diversity, there have been confusion and disagreement in the terminology, classification and subclassification of this lesion. Regarding the nature of COC, there have been two concepts, which are contradictory to each other. The first concept is the "monistic" one that all COCs are neoplastic in nature, even though most are cystic in architecture and appear to be nonneoplastic. The second is the "dualistic" concept that COC contains two entities: a cyst and a neoplasm. Although the World Health Organization (WHO) adopted the former concept in 1992, now it seems to be difficult to decide which of the two is appropriate. Therefore, based on the two concepts, the author proposes two new simple and basic classifications with several new terms for this lesion: the "monistic" classification and the "dualistic" one. In the "monistic" classification, a new term "calcifying odontogenic tumor (COT)" may be more appropriate to represent a neoplastic lesion than the familiar term "COC". If the "dualistic" concept is in fact true, the W H O classification (1992) should be revised. In the "dualistic" classification, the use of the term "COC" should be restricted to true cystic (non-iaeoplastic) entities, which should be classified as developmental odontogenic cysts. On the other hand, the neoplastic entities, which should be classified as benign odontogenic tumors, may be termed COT. In both of the two classifications, the COT, which may also be termed odontogenic ghost cell tumor (OGCT; WHO, 1992) or calcifying ghost cell odontogenic tumor (CGCOT; FEJE~SKOV & KROGI~, 1972), can be either cystic (cystic COT) or solid (solid COT) in architecture. The solid COT may also be termed dentinogenic ghost cell tumor (DGCT; PRAETORIUS et al., 1981) or epithelial odontogenic ghost cell tumor (EOGCT; ELLIS & SHMOOKLER, 1986).
2. The Relationship between Intracystie Fluid Pressure and Fluid Osmolality in Jaw Cysts
Kimura, H., Narita, A., Fukui, R. Department of Dentistry and Oral Surgery, Hirosaki Univ., Hirosaki, Japan It is well known that the increase in intracystic fluid pressure is an important factor in cyst enlargement accompanying pathological bone absorption. However, accurate data of the intracystic pressure and osmolality of cyst fluid in the same
55
patients has not been reported. Therefore, we measured both the intracystic fluid pressure (IFP) of jaw cysts and the colloid osmotic pressure (COP) of cyst fluids. On the basis of clinical and radiologic findings, 43 patients with jaw cysts were selected for I F P and COP measurement. According to the W H O classification, there were 11 cases of odontogenic cysts, 4 of non-odontogenic cysts, 16 of inflammatory cysts, and 12 of postoperative maxillary cysts. By puncturing under local anesthesia, I F P was directly measured with a pressure transducer. Just after I F P measurement, cyst fluid was aspirated to measure COP by a Colloid Osmometer (Wescor Co., USA). The mean value of maximal I F P was 30.8-+18.9 (SD) mmHg. That of COP was 24.4+13.3 mmHg. There was a weak and proportional correlation between I F P and COR Owing to the histological typing of jaw cysts, inflammatory cysts showed higher values of IFP and COP than odontogenic cysts. Some cases were treated with irrigation therapy, which replaced cyst fluid with physiological saline once a month. Jaw cysts treated with this therapy gradually decreased in size with corresponding declines of IFP and COR These results revealed that intracystic fluid pressure was closely related to the colloid osmolality of cyst fluid and that the increase in intracystic pressure was induced by the inflammation of cyst wall tissues. The findings also suggested that microvascular injury was responsible for bone absorption in jaw cysts.
3. Blandin-Nuhn Cysts: Report of Six Cases
Tamaki, H., Taniguchi, S., Kondo, S., Watanabe, K., Kato, K., Yasuda, J.-L Department of Dentistry and Oral Surgery, Nagoya National Hospital, Nagoya, Japan Blandin-Nuhn cyst, which is a comparatively rare mucocele occurring in anterior lingual salivary glands, has been reported to clinico-statistically represent ca. 10% of salivary gland-originating mucous cysts. Having experienced 6 cases of this cyst, we would like to report the outline of their clinical and histological examinations. Salivary gland-originating mucous cysts, as treated by our department during the past 11 years totaled 84, of which 8.3% were represented by Blandin-Nuhn cyst. For the above 6 cases of Blandin-Nuhn cysts, the ratio of incidence by sexes was 1:2 with female predominance and the age distribution ranged from 7 to 15 years with 3 cases below 10 and 3 teenage cases (averaging 10.7). Cysts protruded extraversively from the mucosal surface and were hemispherical oval. Cyst diameter was 3 and 12 mm minimally and maximally, respectively, being under 10 mm in most cases. These 6 patients were suffering from illness for ~ 8 weeks, averaging 4. Only one patient had a past history of traumatism and a description of bad habits. Preoperative diagnosis was mucous cyst in 5 cases and lingual tumor in one case, with the diagnostic efficacy being high. The treatment was always made via resection, without any case of postoperative relapse. The histological diagnosis was extravasation type mucous cyst in all cases. Atrophic acinus and inflammatory granulation tissue were observed in all cases. Formation of an obvious cystic