Yasuo Fukuda

β-Catenin Mutations Are Frequent in Calcifying Odontogenic Cysts, but Rare in Ameloblastomas

We have reported previously that alterations to beta-catenin occur frequently in adamantinomatous craniopharyngioma. Based on its histological resemblance to some odontogenic tumors, we suspected the presence of common genetic alterations among these tumors. To address this issue, 11 cases of calcifying odontogenic cyst (COC) and 20 cases of ameloblastoma were investigated for the presence of beta-catenin mutations and beta-catenin expression. Ten COCs were successfully analyzed by direct sequencing, and nine of them were found to harbor somatic beta-catenin mutations. Immunohistochemically, all of the COCs showed nuclear and cytoplasmic expression of beta-catenin with a heterogeneous pattern. No beta-catenin mutations were found in ameloblastomas, except for one case of the follicular type. All follicular ameloblastomas exhibited moderate nuclear and cytoplasmic accumulation of beta-catenin, in contrast to the predominantly membranous expression seen in the plexiform type. beta-Catenin mutation is considered to be a characteristic genetic feature of COC, and may play a critical role in its histogenesis. Although ameloblastoma closely resembles COC histologically, the two have genetically distinctive features.

Intercellular adhesion molecule-1 (ICAM-1) expression correlates with oral cancer progression and induces macrophage/cancer cell adhesion

Intercellular adhesion molecule‐1 (ICAM‐1) is a transmembrane glycoprotein in the immunoglobulin superfamily, which plays an important role in cell adhesion and signal transduction. Although ICAM‐1 is believed to play a role in several malignancies, it is still uncertain whether or not ICAM‐1 expression contributes to cancer progression. In this study, we performed clinicopathological and cell biological analyses of ICAM‐1 expression in oral squamous cell carcinoma (SCC). First, we examined the ICAM‐1 expression in tongue SCC immunohistochemically, and revealed that ICAM‐1 was expressed predominantly at the invasive front area of tongue SCC. ICAM‐1 expression at the invasive front area was correlated with invasion, lymph node metastasis and increased blood and lymphatic vessel density of the tongue SCC. The relationship between ICAM‐1 expression and clinicopathological factors were consistent with the increased proliferation, invasion and cytokine‐production activities of ICAM‐1‐transfected SCC cells. Second, we analyzed the relationship between macrophages and ICAM‐1‐expressing tongue SCC cells because ICAM‐1 is known to act as a ligand for adhesion of immune cells. Increased ICAM‐1 expression in tongue SCC was correlated with increased macrophage infiltration within SCC nests. Moreover, macrophage/SCC‐cell adhesion through ICAM‐1 molecule was revealed using an in vitro cell adhesion and blockade assay. These findings indicate that ICAM‐1 plays an important role in tongue SCC progression, which may result from the SCC‐cell activity, angiogenic activity, lymphangiogenic activity and macrophage/SCC‐cell adhesion.

Plasmacytoid cells in salivary-gland pleomorphic adenomas: evidence of luminal cell differentiation.

To determine the cellular origin of plasmacytoid cells in salivary gland adenomas, immunohistochemistry was performed on sections from 12 pleomorphic adenomas rich in these cells. In normal salivary glands included in these sections, the myoepithelial cells (MECs) expressed α-smooth muscle actin (αSMA) and smooth muscle myosin heavy chain (SMMHC), whereas the duct luminal cells expressed keratins 19, 18 and 8. Some of the salivary duct basal cells expressed these keratins, and the acinar cells expressed keratins 18 and 8. The expression profile was similar in rat salivary glands not only after but also during development. The immature MECs never expressed the keratins nor did the immature duct cells express αSMA. In seven cases, up to 60% of the plasmacytoid cells expressed keratin 19. In three of these cases, about 10% of the plasmacytoid cells expressed keratin 18. No plasmacytoid cells expressed αSMA, SMMHC or keratin 8. These results indicate that plasmacytoid cells originate from luminal cells and not from MECs. Furthermore, in addition to the luminal tumor cells, the non-luminal cells could express keratins 19, 18 and 8. Therefore, it is necessary to re-evaluate the prevailing notion that non-luminal cells are modified MECs. Keratin 14, basic calponin, vimentin and p63 were bi-specific for the MECs and the duct cells. Therefore, expression of these proteins by significant numbers of the non-luminal tumor cells and the plasmacytoid cells never denied the above notion.

Malignant schwannoma of the mandible

A case of malignant schwannoma occurring in the mandible of a 76-year-old Japanese woman is presented. Results of the gross examination are described as well as the surgical procedure. Details of the staining techniques for examination of the biopsy specimen are given. The histopathological findings are mentioned including those obtained from radiographic, microscopic, and electron microscopic examination. A discussion of the disease and of its difficulty of diagnosis follows.

PRIMARY GASTRIC CHORIOCARCINOMA: Report of an Autospsy Case with Immunohistochemical Study

An autopsy case of primary gastric choriocarcinoma of a 70‐year‐old Japanese female is presented. The tumor was initially diagnosed as poorly differentiated adenocarcinoma of the stomach by biopsy. Autopsy revealed co‐existence of choriocarcinoma and adenocarcinoma in the stomach and a large amount of human chorionic gonadotropin in the serum. The choriocarcinoma metastasized to the liver, lung, and omentum, and the adenocarcinoma to lymph nodes. In the gastric tumor, immunohistochemical stains showed human chorionic gonadotropin in choriocarcinoma cells, alpha‐fetoprotein and carcinoembryonic antigen in adenocarcinoma cells. The pathogenesis and pathological characteristics of primary gastric choriocarcinoma are discussed. ACTA PATHOL. JPN. 35 : 655–666, 1985.

Nasolabial cyst in a patient with cleft lip and palate

Nasolabial cysts are rare non-odontogenic cysts that occur beneath the ala nasi, and debate about their complicated, unique pathogenesis continues. It is widely accepted that these lesions originate from the anlage of the nasolacrimal duct; however, some still think that nasolabial cysts arise from fissural cysts. The authors report a patient with a nasolabial cyst who also had a unilateral cleft lip and palate. This unusual finding may indicate a different origin for nasolabial cysts than what has been accepted in the past.

Alveolar soft-part sarcoma of the tongue. Report of a case

A case of alveolar soft-part sarcoma (ASPS) of the tongue in a 19-year-old boy is presented. He underwent a hemiglossectomy and received chemotherapy and has been free of disease for 3 years. The origin of intracytoplasmic periodic acid-Shiff(PAS)-positive crystals found in the tumor and the histogenesis of ASPS are briefly discussed.

Clinicopathological study of odontogenic keratocyst

Fifty-five cases of odontogenic keratocyst in the mandible were classified into two subtypes according to the histopathologic characteristics of the epithelium (Group-1; the epithelium was parakeratotic with cuboidal or columnar, accentuated and palisadelike arranged basal cells, Group-2; the epithelium was orthokeratotic with a distinct stratum granulosum.) and were examined for the following four factors; 1) age distribution, 2) size of bone destruction, 3) degree of lateral bone expansion, and 4) features of the cyst contents. Most cases of Group-1 indicated radiographically lateral bone expansion and large cystic bone destruction and had fluid cyst content. On the contrary, the majority of Group-2 cases indicated no lateral bone expansion, were relatively small lesions, and their cystic cavities were filled with caseous materials.

An analysis of the prognostic significance of p53 status for squamous cell carcinoma of the oral cavity treated by radiotherapy.

The status of the p53 gene in biopsy specimens was analyzed to determine whether it is predictive of the outcome of radiotherapy of squamous cell carcinomas of the oral cavity. Biopsy materials were obtained from 45 patients, and the p53 status of each patient was determined using a single-strand conformation polymorphism analysis. Fourteen of the patients were treated with radiation therapy alone; the other 31 patients underwent radiotherapy in combination with surgery or chemotherapy. Twenty-seven patients had tumors with wild-type p53 and 18 patients had a tumor with mutant p53. The initial tumor response was not significantly different between these two groups. Kaplan-Meier survival plots (log-rank test) showed that the probability of survival was not significantly different between two groups although the patients with mutant p53 had a tendency for longer survival (P = 0.2941). However, among the patients with stage III/IV tumors (n = 24), those with a wild-type p53 status tended to have longer survivals.

Granular cell ameloblastoma. A rare variant

A rare case of granular cell ameloblastoma in the anterior mandible of a 59-year-old man has been studied by light and electron microscopy. In some areas, the tumor was very similar to an oncocytoma (oxyphilic adenoma). Almost all tumor cells were full of eosinophilic granules, whereas in the common type of granular cell ameloblastoma, only the cells located in the central portion of the tumor are granular.