Motoo Yokoi

MECT1-MAML2 Fusion Transcript Defines a Favorable Subset of Mucoepidermoid Carcinoma

Purpose: Mucoepidermoid carcinoma is the most common primary malignancy of the salivary gland. Mucoepidermoid carcinoma translocated gene 1-mastermind-like gene family (MECT1-MAML2) gene fusion was identified from a recurring t(11;19)(q21;p13) translocation, which is often the sole cytogenetic alteration in this disease. This fusion transcript has been frequently detected in mucoepidermoid carcinoma and shown to be involved in the transformation of epithelial cells. However, its clinicopathologic significance remains unclear. Experimental Design: Seventy-one cases of mucoepidermoid carcinoma and 51 cases of nonmucoepidermoid carcinoma salivary gland tumors (including 26 Warthin tumor cases) were retrospectively analyzed. RNA was extracted from archival materials: histologic paraffin specimens in all cases and cytologic specimens in 10 mucoepidermoid carcinoma cases. The MECT1-MAML2 fusion transcript was detected by a reverse transcription-PCR assay, which can be applied to both histologic and cytologic specimens. The presence of the fusion transcript was correlated with relevant clinicopathologic and survival data of the mucoepidermoid carcinoma patients. Results: The MECT1-MAML2 fusion transcript was detected in 27 of the 71 (38%) mucoepidermoid carcinoma cases but not in any case of nonmucoepidermoid carcinoma tumors. The reverse transcription-PCR results showed no difference between histologic and cytologic specimens. Detection of the MECT1-MAML2 fusion transcript was associated with a less advanced clinical stage and a low-grade tumor histology. The presence of the transcript was associated with longer disease-free and overall survivals on univariate analysis and emerged as an independent prognostic factor for longer overall survival on multivariate analysis. Conclusions: The MECT1-MAML2 fusion transcript may be specific to mucoepidermoid carcinoma and associated with a distinct mucoepidermoid carcinoma subset that exhibits favorable clinicopathologic features and an indolent clinical course.

Prognostic factors for keratocystic odontogenic tumor (odontogenic keratocyst): analysis of clinico-pathologic and immunohistochemical findings in cysts treated by enucleation

BACKGROUND The purpose of this study was to determine prognostic factors for the recurrence of keratocystic odontogenic tumors (KCOTs) following simple enucleation by examining clinico-pathologic and immunohistochemical findings. METHODS Following enucleation, the frequency of recurrence among 32 subjects diagnosed with KCOT was analyzed for tumor site, radiographic and histologic features, and immunopositivity for Ki-67 and p53. RESULTS Keratocystic odontogenic tumors in four out of 32 subjects (12.5%) recurred during the follow-up period (median: 33 months, range: 7-114 months). Three out of four subjects (75.0%) among recurrent group showed high expression of Ki-67 (LI >10%) in basal layer and four (4/28; 14.3%) among non-recurrence group (P = 0.025). Expression of p53 among non-recurrent group was observed in 11 subjects (11/28; 39.3%), and in three subjects (3/4; 75.0%) among the recurrent group (P = 0.295). Hazard risk for the recurrence of KCOT was 4.02 (95% CI 1.42-18.14) for high Ki-67 expression in the basal layer by the Cox proportional hazard model (P = 0.009). In our study, none of the other clinico-pathologic variables were associated with the recurrence of KCOT. CONCLUSION The results suggested that the evaluation of Ki-67 expression in KCOT at the time of pathological diagnosis might be helpful for consideration of appropriate adjunctive surgical procedures to avoid a recurrence and may serve as a prognostic marker.

Prognostic significance of p27Kip1, Ki-67, and CRTC1-MAML2 fusion transcript in mucoepidermoid carcinoma: a molecular and clinicopathologic study of 101 cases.

PURPOSE Mucoepidermoid carcinoma (MEC) is the most frequently detected primary malignancy of the salivary gland and is characterized by a marked variation in prognosis. In the present study, we investigated the prognostic significance of p27Kip1, Ki-67, and CRTC1 (also called MECT1, TORC1, and WAMTP1)-MAML2 fusion in MEC. MATERIALS AND METHODS MEC cases (n = 101) were examined for p27Kip1 and Ki-67 expression using immunohistochemistry and for CRTC1-MAML2 fusion transcript using reverse transcriptase-polymerase chain reaction. RESULTS p27Kip1, Ki-67, and the CRTC1-MAML2 fusion transcript were expressed in 71, 31, and 34 of the 101 cases, respectively. p27Kip1 and CRTC1-MAML2 fusion were associated with favorable clinicopathologic tumor features and Ki-67 with aggressive clinicopathologic features. Multivariate survival analyses were performed that included the following 10 clinicopathologic factors: age, gender, tumor site, tumor size, nodal metastasis, clinical stage, histologic grade, p27 expression, Ki-67 expression, and CRTC1-MAML2 fusion. For disease-free survival, only p27Kip1 expression was significant as an independent prognostic factor. For overall survival, p27Kip1 expression, CRTC1-MAML2 fusion, and tumor size were significant. In each analysis, p27Kip1 and CRTC1-MAML2 fusion were independent of the clinical stage. Ki-67 expression was not selected in either multivariate analysis. CONCLUSIONS p27Kip1 and CRTC1-MAML2 fusion were associated with favorable clinicopathologic tumor features, and both were useful in predicting the overall survival of patients with MEC. For disease-free survival, p27Kip1 might be the most useful prognostic factor. In contrast, Ki-67 might not be a very powerful prognostic indicator for either survival point.

Spontaneous regression of intraoral mucosa-associated lymphoid tissue lymphoma: Molecular study of a case

Mucosa‐associated lymphoid tissue (MALT) lymphoma presentation in the oral cavity is very rare. Reported herein is a case of intraoral MALT lymphoma of the minor salivary gland in a 70‐year‐old woman with Sjogren’s syndrome. Unexpectedly, a spontaneous clinically and histologically confirmed regression occurred 1 month after the tumor biopsy for diagnosis. Considering that salivary MALT lymphoma is associated with Sjogren’s syndrome and that the chronic inflammation caused by Sjogren’s syndrome persisted, it is hypothesized that the tumor clone might be present in the regressed lesion. Minimal residual tumor clone identical with the primary lesion was detected using the polymerase chain reaction (PCR) clonality assay for immunoglobulin heavy chain gene (IgH) rearrangement. No recurrence was clinically evident 38 months after the diagnosis. Spontaneous regression of MALT lymphoma should be examined at the molecular level in addition to clinical and histological evaluations. When minimal residual disease is detected, close follow up is necessary for early detection of the tumor relapse.

Platelet-rich fibrin has a healing effect on chemotherapy-induced mucositis in hamsters

OBJECTIVE The aim of this study was to evaluate the healing effect of topically applied platelet-rich fibrin (PRF) on experimental oral mucositis induced by chemotherapy in hamsters. STUDY DESIGN Oral mucositis was induced in 93 Syrian golden hamsters by an intraperitoneal injection of 5-fluorouracil, which was followed by light scratching of the cheek pouch. The hamsters were randomly divided into a PRF group, a fibrin group, and an untreated control group. The recovery stage of oral mucositis was evaluated through daily weighing, measurements of the ulcer area, histopathologic analysis, and a myeloperoxidase activity assay. RESULTS The PRF group exhibited significant improvements in the size and histologic features of the ulcer and in the myeloperoxidase activity compared with the control group (P < .05). CONCLUSIONS The current findings suggest the consideration for future clinical trials in humans.

Pneumomediastinum secondary to hyperemesis gravidarum during early pregnancy

Pneumomediastinum has been well documented under conditions that cause high intra-alveolar or intraesophageal pressures, such as forceful or excessive coughing, persistent emesis with alcohol abuse and labor. Free air subsequently trapped in the mediastinal connective tissue is disseminated from the alveoli along the perivascular fascial planes (1). Pneumomediastinum is a rare complication of pregnancy, in most cases occurring in the second stage of labor (2). To our knowledge, there have been four previous reports in which hyperemesis gravidarum was caused (2-5). In all cases, it was improved by cessation of vomiting. We report here a woman who suffered from severe hyperemesis gravidarum and advanced pneumomediastinum during early pregnancy.

Septic Pulmonary Embolism Ascribed to Periapical Periodontitis:: A Case Report and Review of the Literature

Abstract Septic pulmonary embolism is a rare condition, the common sources of which are bacterial endocarditis and infected venous catheters. Septic pulmonary embolism ascribed to dental infection is extremely rare. The present report describes a case of septic pulmonary embolism attributed to periapical periodontitis in a 39-year-old patient, who was admitted with persistent toothache, fever, and chest pain. Chest CT showed a feeding vessel sign and a target sign. A panoramic radiograph of the left maxillary bone showed alveolar bone loss in a horizontal pattern typical of periodontitis and periapical periodontitis. The patient was treated with intravenous antibiotics and teeth extraction. To our knowledge, only 4 cases of septic pulmonary embolism ascribed to dental infection have been reported in the English literature. These patients repeatedly developed dental infections but did not receive appropriate dental treatment including extraction of the causative teeth, leading to the development of septic pulmonary embolism. This paper may contribute to the limited clinical knowledge base regarding septic pulmonary embolism ascribed to periapical periodontitis. Effective oral care and removal of the primary source of infection, including extraction of the causative teeth, are important to prevent septic pulmonary embolism.