A carcinoma showing thymus-like elements of the thyroid arising in close association with solid cell nests: evidence for a precursor lesion?

Background: Carcinoma showing thymus-like elements (CASTLE) is a rare malignant neoplasm of the thyroid gland, morphologically and immunohistologically similar to a thymic carcinoma, whose histogenesis is still debated. Hypotheses include an origin from ectopic thymic tissue, vestige of the thymopharyngeal duct, or branchial pouch remnants from which solid cell nests (SC-nests) originate. The diagnosis of CASTLE may be treacherous due to its rarity and its propensity to mimic other poorly differentiated tumors such as squamous cell carcinoma.

The prognostic value of expression of HIF1α, EGFR and VEGF-A, in localized prostate cancer for intermediate- and high-risk patients treated with radiation therapy with or without androgen deprivation therapy.

Purpose: Androgens stimulate the production of hypoxia-inducible factor (HIF1α) and ultimately vascular endothelial growth factor (VEGF-A). Additionally, epithelial growth factor (EGF) mediates HIF1α production. Carbonic anhydrase IX (CAIX) expression is associated with tumor cell hypoxia in a variety of malignancies.