Central odontogenic fibroma interesting the maxillary sinus. A case report and literature survey.

Odontogenic fibroma (OF) is a rare benign odontogenic tumor deriving from the dental mesenchymal tissue and accounting for less than 5% of all odontogenic tumors. This paper presents an aggressive histologically diagnosed central odontogenic fibroma (COF) in a 17-year-old girl characterized by asymptomatic rapid growth with massive replenishment of the left maxillary sinus. We carried out a review of the literature to retrieve all published cases of COF especially focused on radiographic aspects and surgical treatment of cases characterized by clinical aggressive behaviour, as we observed in our patient. Search strategy included retrieval of English language papers, published from 1966 to today, in dental journals on MEDLINE/PubMed and EMBASE, and hand-searching of the bibliography of retrieved papers. Sixty-nine cases of COF were identified from 1954 to 2003 and a new one was added. We have compared characteristics of COFs according to age, gender, location, clinical and radiographic findings of aggressive development, and histology. We discuss clinical and radiographic aspects of our case compared with COFs previously published. We give suggestions for surgical treatment of COF in case of aggression to important anatomical structures.

A histological and NMR study of the melon of the striped dolphin (Stenella coeruleoalba).

The melon, the echolocation organ of the striped dolphin (Stenella coeruleoalba), was investigated by morphological and high-resolution (13)C nuclear magnetic resonance (NMR) methods, in order to characterize structure and composition gradient at the histological and molecular level. Morphological analysis showed that the lipidic components are organized in an adipose tissue; moreover, a clear muscular component was observed. Age-related structural differences also were noted. Furthermore, NMR yielded detailed information at a qualitative-quantitative level on the lipid components.

Chromosome aberrations in lymphocytes and clastogenic factors in plasma detected in Belarus children 10 years after Chernobyl accident.

In 1996, 10 years after Chernobyl accident, a cytogenetic analysis was carried out to assess whether chromosome aberrant cells (CA) were still detectable in the lymphocytes and clastogenic factors (CFs) were present in the plasma of children coming from Gomel (Belarus), one of the most heavily contaminated regions. Furthermore, the possible contribution of plasmatic CFs to the amount of CA was investigated. The presence of CA was examined in the lymphocytes from 29 thyroid tumour-affected children and 41 healthy children (local controls). Thirty healthy children living in Pisa (Italy) were enrolled in the study as additional controls from an uncontaminated area. No significant difference was observed between the two control groups, whereas a significantly increased frequency of CA was found in the tumour-affected children, as compared with Gomel and Pisa controls (chi 2-test, p < 0.001). However, when soil contamination level was taken into account, the chromosome type CA frequency observed in tumour-affected children coming from the more contaminated areas (> 4 Ci/km2) resulted significantly higher than that in other children, either affected or not (p = 0.003). The presence of CFs was analyzed on the plasma ultrafiltrate from 41 children. 7/10 (70%) plasma samples from tumour-affected children and 17/23 (74%) Gomel controls resulted to possess clastogenic activity irrespective of soil contamination levels. No activity was detected in the plasma of eight Pisa controls (0%). The difference between both Gomel groups and Pisa controls was highly significant (p = 0.002). A borderline, but not statistically significant correlation (p = 0.08) was observed between basal CA frequency and CF potency, which became significant (p = 0.03) when only chromosome type of aberrations was considered. We conclude that, although the presence of CFs in the plasma of these children might be partly responsible of the cytogenetic effects observed, the main source of damage has considered to be do to the previous and/or continuous exposure to environmental radiocontaminants. Tumour-affected children may represent a subset of the population either more sensitive to clastogenic damage or exposed to higher levels of contaminants.

Calcifying epithelial odontogenic (Pindborg) tumor. A clinical case.

Calcifying epithelial odontogenic tumor (CEOT), Pindborg tumor, is a rare benign odontogenic neoplasm representing about 0.4-3% of all odontogenic tumors. This tumor more frequently affects adults in an age range of 20-60 years, with a peak of incidence between 40 and 60 years. About 190 cases of CEOT have been reported in the dental literature. Fifty-two percent of cases of CEOT is associated with a tooth impacted and/or displaced by the tumor. The primary CEOT has a recurrence rate of 10-15%, after total excision, and its malignant transformation is a very rare occurrence. The authors report a case of primary intra-osseous CEOT, embedding the mandibular right second molar, in a 24 year-old male. Radiographs showed a well-defined unilocular osteolytic lesion, swelling and reabsorbing the mandible and displacing the inferior alveolar nerve. It was possible to perform conservative surgical treatment consisting of the enucleation of the tumor together with a portion of tumor-free bone cavity margin and the debridement of the inferior alveolar neuro-vascular bundle, which was surrounded by a tumor capsule-like structure. The postoperative histological examination of the tumor revealed typical benign features. The differential diagnosis and work-up of the tumor treatment are discussed in relation with its histological typing and localization in the jaws.

The immunophenotype of osteoclasts and macrophage polykaryons.

AIM: Osteoclasts are multinucleated cells which are specialised to carry out lacunar bone resorption. Osteoclasts form part of the mononuclear phagocyte system, and immunophenotypic criteria for distinction from macrophage polykaryons include expression of CD51 (vitronectin receptor) and absence of HLA-DR and CD14. METHODS: The expression of CD14, CD163, HLA-DR and CD51 in formalin-fixed paraffin-embedded sections of normal bone and neoplastic and non-neoplastic lesions of bone and soft tissue known to contain osteoclasts and macrophage polykaryons respectively was assessed immunohistochemically; the immunophenotype of osteoclast-like giant cells in a wide range of giant cell-containing bone lesions was similarly assessed. RESULTS: Both osteoclasts and macrophage polykaryons were found to express CD51. Macrophage polykaryons, but not osteoclasts, expressed CD14 and HLA-DR. CD51+/CD14-/HLA-DR-/CD163- giant cells were noted in all giant-cell lesions of bone, including giant cell tumour of bone, aneurysmal bone cyst, non-ossifying fibroma, chondroblastoma, telangiectatic osteosarcoma, chondromyxoid fibroma, Langerhans cell histiocytosis and brown tumour. CONCLUSION: Our findings indicate that CD51 expression alone is not sufficient for immunocytochemical identification of osteoclasts, which do not express the macrophage-associated antigens CD14 and HLA-DR. Giant cells in most giant cell-rich lesions of bone have an osteoclast phenotype, suggesting that they are formed from mononuclear phagocyte osteoclast precursors.

A morphological and 13C NMR study of the extramandibular fat bodies of the striped dolphin (Stenella coeruleoalba).

The molecular and histological structure of the fat bodies covering externally the posterolateral region of the jaw of the striped dolphin (Stenella coeruleoalba) was investigated by means of morphological and nuclear magnetic resonance techniques. The analyses of samples belonging to adult and juvenile individuals were performed with the aim of seeking the presence of age-related differences. In our study, the level of isovalerate (iso5:0) in the extramandibular fat of the juvenile individuals is comparable with those of the adult counterparts; conversely, longer isobranched fatty acids were detected in lower quantities in the juveniles together with a higher degree of unsaturation. The morphologic analyses revealed that, in both adults and juveniles, this fatty tissue is similar to univacuolar adipose tissue. However, in the juveniles, a muscular component was present, whereas only in adult subjects, enlarged and irregularly shaped cavities may be seen within the adipose tissue. These cavities, structurally organized as veins, may regulate blood flow in response to changing water temperature and stabilize thermal gradient within the jaw lipids. These data suggest that the molecular components and the histological organization can indicate a maturation of the organ with age that probably may reflect different sound reception properties.