Ectopic thyroid tissue can be seen anywhere from the foramen caecum to the lower neck. Most frequently it presents as a thyroglossal duct cyst associated with a normal thyroid gland. Less common is total ectopia, which can occur as a lingual thyroid or occasionally in non-lingual locations. Malignant transformation of such ectopic tissue is extremely uncommon. Only 21 cases of lingual thyroid carcinomas have been reported until 1971. We present, to our knowledge, the first case of a papillary carcinoma in a non-lingual ectopic thyroid in the absence of an orthotopic thyroid.
Transport in fractured media plays an important role in a range of processes, from rock weathering and microbial processes to contaminant transport, and energy extraction and storage. Diffusive transfer between the fracture fluid and the rock matrix is often a key element in these applications. But the multiscale heterogeneity of fractures renders the field assessment of these processes extremely challenging. This study explores the use of dissolved gases as tracers of fracture‐matrix interactions, which can be measured continuously and highly accurately using mobile mass spectrometers. Since their diffusion coefficients vary significantly, multiple gases are used to probe different scales of fracture‐matrix exchanges. Tracer tests with helium, xenon, and argon were performed in a fractured chalk aquifer, and resulting tracer breakthrough curves are modeled. Results show that continuous dissolved gas tracing with multiple tracers provides key constrains on fracture‐matrix interactions and reveal unexpected scale effects in fracture‐matrix exchange rates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.