Following breast and lung cancers, renal cell carcinoma (RCC) is the third most frequent cancer to metastasize to the head and neck region, though such cases are rarely reported. Distinguishing between malignant tumors of salivary gland origin and metastatic RCC is very important. The case of a 75-year-old man with an oral cavity lesion in the left buccal submucosa measuring 40×30 mm that had grown substantially over several weeks is presented. His medical history included left kidney cancer 26 years earlier and a malignant myoepithelioma of the left buccal region 7 years earlier. It was suspected that this lesion was a recurrent malignant myoepithelioma as it appeared at the same site as the previous operation. Surgery was performed, and metastatic RCC was confirmed upon pathological examination. The diagnosis of metastatic RCC was made by immunohistochemical examination, which also excluded malignant myoepithelioma and other clear cell carcinomas of salivary gland origin. Metastatic RCC must be considered in the differential diagnosis of a new oral cavity lesion presenting in a patient with a past history of kidney cancer. Thus, immunohistochemical staining is required to distinguish malignancies of salivary gland origin, including malignant myoepithelioma, from metastatic RCC.

BackgroundBoron neutron capture therapy (BNCT) is a selective radiotherapy that is dependent on the accumulation of 10B compound in tumors. Low-intensity ultrasound produces a transient pore on cell membranes, sonoporation, which enables extracellular materials to enter cells. The effect of sonoporation on BNCT was examined in oral squamous cell carcinoma (SCC) xenografts in nude mice.Materials and methodsTumor-bearing mice were administrated boronophenylalanine (BPA) or boronocaptate sodium (BSH) intraperitoneally. Two hours later, tumors were subjected to sonoporation using microbubbles followed by neutron irradiation.ResultsThe 10B concentration was higher in tumors treated with sonoporation than in untreated tumors, although the difference was not significant in BPA. When tumors in mice that received BPA intraperitoneally were treated with sonoporation followed by exposure to thermal neutrons, tumor volume was markedly reduced and the survival rate was prolonged. Such enhancements by sonoporation were not observed in mice treated with BSH-mediated BNCT.ConclusionsThese results indicate that sonoporation enhances the efficiency of BPA-mediated BNCT for oral SCC. Sonoporation may modulate the microlocalization of BPA and BSH in tumors and increase their intracellular levels.

Background: In boron neutron capture therapy (BNCT), the intravenous administration of boron-containing compounds such as boronophenylalanine (BPA) and borocaptate sodium (BSH) is followed by irradiation with thermal neutrons. In the present study, we determined whether a boron-rich boron carbide (B 4 C) nanoparticle could be used for BNCT.

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Schwannomas originating from the hypoglossal nerve are extremely rare neoplasms. Hypoglossal schwannomas usually occur between the third and fifth decades of life, with no sex predilection, commonly presenting as a painless, slow-growing, and lateral neck mass. The best treatment is complete surgical excision with preservation of the neural pathway, if possible. In fact, since these tumors are almost always benign, a conservative surgical approach is emphasized by most authors. We report a case of a large schwannoma of hypoglossal nerve origin in the upper neck in a 31-year-old male. Magnetic resonance imaging of the area demonstrated a 43 × 39 × 36 mm well-circumscribed mass with high and nonhomogeneous signal intensity on the right side of the upper neck. The lesion was successfully treated by extirpation, with no recurrence. The extracranial hypoglossal nerve sheath was as the origin of this tumor because the patient experienced remarkable disturbance of tongue motility after surgery.