Primary Circumscribed Meningeal Melanoma Involving the Meckel's Cave: A Report of a Rare Case and Review of Literature.

Primary intracranial meningeal melanomas are rare. Diagnosing primary meningeal melanomas mostly involves comprehensive assessment through clinical and radiological means. This evaluation should encompass a detailed dermal and ophthalmic examination.

Secondary Ameloblastic Carcinoma of Mandible with Pulmonary Metastasis.

Ameloblastic carcinoma (AC) is a very rare odontogenic malignancy. Primary AC is more common in maxilla, while secondary AC is more common in mandible. Histologically, it is an ameloblastoma with features of cancer.

C-H activation with elemental sulfur: synthesis of cyclic thioureas from formaldehyde aminals and S8.

The C-H activation of cyclic formaldehyde aminals LCH2 (L = RN-CH2CH2CH2-NR and RNCH2CH2-NR, R = Me, Et, iPr, tBu, or Ph) with S8 proceeds at unusually low temperatures (T< 160 degrees C) and results in the formation of the respective thioureas LC=S and H2S. The reaction constitutes a new, solvent-free method for the synthesis of thioureas that eliminates the toxic and highly flammable CS2. For R = tBu, the ionic carbenium thiocyanates [LCH]+ SCN- dominate the product spectrum and the respective thioureas are obtained in low yield.