No abstract

We dissected 30 facial nerves in fresh cadavers after arterial casting with red latex to provide specific information about the arterial-related anatomy of the trunk of the facial nerve from the stylomastoid foramen to its bifurcation. We found that a wide anatomic variability does exist. The trunk of the facial nerve was in proximity to the stylomastoid artery, which originated from the posterior auricular artery in 70% of the specimens (21/30), from the occipital artery in 20% (6/30), and directly from the external carotid artery in 10% (3/30). The stylomastoid artery passed medially to the trunk of the facial nerve in 63 of the specimens (19/30) and laterally in 37% (11/30). Among these 11 specimens, 8 were large-caliber stylomastoid arteries. During parotid surgery, the main trunk of the facial nerve may be difficult to identify, because a large-caliber stylomastoid artery can mask it. Therefore, it is important to dissect this artery with caution.

AIM: Only limited information is available on the molecular characteristics of colorectal cancers diagnosed in patients 90 years and older. There are indirect suggestions that in cancers from very elderly patients, molecular genetic changes may be either more, or less prevalent; thus, raising the question as to the similarity in genetic changes found in colorectal cancers between very elderly and younger patients. We examined several molecular changes associated with colorectal cancers in 41 very elderly patients, and compared the results to the findings of a younger cohort, between ages 55 and 79 years. METHODS: We evaluated MSI, loss of heterozygosity for APC and DCC genes, KRAS and BRAF gene mutations, and DNA methylation in colon cancer tissue samples using standard PCR techniques. RESULTS: our data indicate that colorectal cancers from very elderly patients are more frequently right-sided and more likely to demonstrate microsatellite instability. If the cancers contain a KRAS mutation, it is less likely to be in the second codon position. Finally, KRAS 61 may be more frequent in the very elderly. CONCLUSIONS: Overall, the colorectal cancers from our very elderly patients, 90 years and older, have at least as many, if not more, molecular genetic changes than the cancers from younger.