Diferentiated thyroid cancer is uncommon in children and adolescents. It presents as a solitary thyroid nodule, as multinodular goiter, or as a neck mass that is noted accidentally by the patient, the family or by the physician. Surgery is the treatment of choice and most of the specialists consider that total thyroidectomy with central cervical lymph nodes dissection must be applied in all patients. Some specialists prefer a more conservative surgical treatment in order to avoid complications. Postoperatively, ablation treatment with iodine-131, for the eradication of the remaining normal or malignant thyroid tissue is indicated in the majority of patients. Thyroid hormone is administered for life. Follow-up is continued for many years.

The second part of this review describes the advantages, and evaluates the radionuclide-guided methods for sentinel lymph node localization and also evaluates the intraoperative application of the blue dye technique in melanoma. By combining the two techniques, the detection rate rises to 96%-98%. The presence of cancer cells in the sentinel node is histopathologically shown by using hematoxylin-eosin and by using sensitive techniques for the detection of micrometastases. Immunohistochemical tech-niques specific for epithelial markers and polymerase chain reaction examination are also applied. Sentinel lymph node biopsy suggests whether regional elective lymphade-nectomy shall be performed.

Gastro-entero-pancreatic tumors (GEP) contain, in their majority, somatostatin receptors. In-111-DTPA-phenyl-pentetreotide has been proved to have high affinity for somatostatin receptors subtypes 2, 3 and 5. The aim of the present study was to evaluate the utility of (111)In-DTPA-O somatostatin receptors' scintigraphy (SRS) in the diagnosis of suspected GEP. Thirty-five consecutive patients (17 males and 18 females-mean age 57.9+/-7.6) with GEP as a possible diagnosis were enrolled in the study. The primary diagnosis was diarrheic syndrome susceptive of intestinal carcinoid tumor (24 patients), carcinoid of the rectum (2 patients), adenocarcinoma of the pancreas (2 patients), insulinoma (2 patients), gastrinoma (3 patients) and hepatocellular carcinoma (2 patients). All patients were submitted to computerized tomography (CT) of the thorax and the abdomen and pentetreotide SRS was performed 4 h (total body and SPET acquisition) and 24 h (planar views), post iv injection of 185 MBq of the radiolabeled compound. Results showed: Four of the patients were false positive diagnosed as having inflammatory intestinal disease and gallbladder dilatation. At the time of the evaluation, 14 of the remaining patients were free of disease, concerning secondary involvement. In these cases, CT and SRS studies matched each other, with no pathological lesions and no abnormal accumulation of the radiopharmaceutical respectively. Concerning pathological cases, only one SRS study in a patient with rectum carcinoid was normal, with liver lesions in the CT study. These lesions were considered as subtypes 2, 3 and 5 somatostatin receptors negative. SRS revealed three lesions more than CT. According to these results, sensitivity of SRS study was 93.8% and specificity 86.9%. The authors believe that molecular imaging of somatostatin receptors, is a sensitive method for the evaluation of patients with GEP tumors. However, in cases of intestinal disease, we should be aware of false positive results due to inflammatory processes and the presence of lymphocyte infiltration.

Morphologic characterization of brain tumors by magnetic resonance imaging and computed tomography is well established. However, functional metabolic imaging by single-photon emission tomography (SPET) and positron emission tomography are also increasingly important imaging tools for noninvasive assessment of brain tumors. Brain SPET is useful in the differentiation of tumor recurrence from radiation necrosis, in the non-invasive assessment of gliomas and meningiomas aggressiveness, in differentiating neoplastic from non neoplastic intracerebral haemorrhage, in monitoring therapy response and in the evaluation of other types of brain tumors. Our own experience is presented supporting the above.

A case of peripheral ameloblastoma is presented which was located in the right maxillary tuberosity area in a 52-year-old caucasian male. The lesion was asymptomatic and presented as a reddish sessile mass of soft tissue, 1.5 cm in diameter, with a granular surface and firm texture (Fig. 1). There was no radiologic evidence of bone involvement (Fig. 2). A clinical diagnosis of squamous cell carcinoma was made and a biopsy was taken. The microscopical examination revealed the presence of ameloblastomatous tissue exhibiting numerous areas of continuity with the surface epithelium (Fig. 3). The tumor showed a mixed follicular (Fig. 4) and plexiform (Fig. 5) pattern and was accompanied by a mild lymphocytic infiltrate (Fig. 3). A partial maxillectomy was performed and the histopathological examination of the surgical specimen confirmed the diagnosis of peripheral ameloblastoma. A primary basaloid pattern of the tumor was identified (Fig. 6) but a search for acanthomatous areas was proved fruitless. Some epithelial islands showed peripheral columnar cells with apically polarized nuclei (Fig. 7). The space between the border of the tumor (Fig. 8) and the underlying bone was filled with dense connective tissue and contained two isolated tumor follicles with cystic change (Fig. 9). The thorough examination of the co-existed bone did not reveal any areas of tumor invasion. Finally, the oral epithelium adjacent to the tumor exhibited elongated and slender rete ridges (Fig. 10). One and a half year post-operatively, no signs of recurrence could be detected.

Three cases of invasion of the mandible by squamous carcinomas of the oral cavity are presented in this study. The current literature is reviewed and the diagnostic capabilities of contemporary imaging methods are emphasised. The detection of the location and extent of the possible infiltration of the mandible is a determinant factor concerning the choice of treatment and prognosis.

The purpose of this study was to present the clinical and histological features of one case of lateral periodontal cyst with keratinization. The incidence, the histological features and the aetiopathogenesis of this type of cyst that is recurred were discussed.

Polymorphous low-grade adenocarcinoma is a distinct type of salivary gland carcinoma arising most often intraorally and primarily in the palate. It is characterized by bland nuclear chromatin, variation in histomorphology and low-grade malignancy. We report a case of this recently described entity in a 66 year old male, presenting most of the characteristic clinical and histologic features. A short review of the current literature concerning this tumor is included.

An unusual case of pleomorphic adenoma displaying numerous horny pearls is described. The tumour arose in the right lateral lingual border of a 33-year-old man. In many pearls the cores were organized in two separate portions with distinct structural and histochemical features. The narrow peripheral portion had a compact structure and was rich in keratin since it contained cystine and was coloured with acid dyes of intermediate molecular size. The central portion was characterized by a loose texture and its histochemical profile (affinity for acid dyes of large molecular size, weak alcianophilia, vivid binding of colloidal iron) resulted from the existence of acidic mucosubstances in the cell coating of the neoplastic keratinized cells. These observations suggest that certain similarities exist between the processes of normal keratinization and squamous metaplasia in pleomorphic adenoma.

The mucous retention cyst of the minor salivary glands represent a specific type of oral mucocele which is lined by epithelium. It is caused probably from partial or complete obstruction of a duct. It affects older patients (over 40 years of age) most commonly women and it is located in different sites than the ordinary mucocele. In this paper we studied the histologic and histochemical features of four cases. The lining epithelium varied from cuboidal to columnar or flattened. Among the cells of the lining epithelium oncocytes were observed.

Fifty children with oral manifestations of acute leukemia, ranging in age from 1 to 14 years, have been studied with reference to age, sex, location and clinical presentation of the oral lesions. Seventy six percent of the patients had the disease during the first decade of their life, 22% as acute myelocytic leukemia and 54% as acute lymphocytic leukemia. In the current study, acute leukemia exhibited a high predilection for males (70%) and mucosal pallor was the most common presenting oral symptoms (39.6%). Erythema, ulceration and swelling of the lip, tongue, palate and gingiva were also frequent symptoms. Extra oral involvement occurred in 60% of the cases as facial pallor and 11% as lymph node enlargement.

The embryonal rhabdomyosarcoma is a very rare entity particularly when it occurs intraorally. We are reporting such a case in a 16-month old child.

In this study an attempt was made to correlate the causative factors of leukoplakia. Histologic criteria helped for the classification of our cases in three groups according to widely accepted standards. As final result it is that smoking and excess use of alcoholic drinks could be involved as causative agents. The clinical appearance of the leukoplakia lesions with their histological type is also correlated.

A 73 year-old male with a Kaposi's sarcoma presenting as multiple, red-purple papules and nodules on the vermillion border and as ulcerations on the labial mucosa, is described. No other skin or organ involvements were found. The main clinical and histopathological characteristics of the classic form of Kaposi's sarcoma are briefly discussed and the recent aspects on tumor histogenesis and pathogenesis are analysed.