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Histopathology Jan 2024Mediastinal tumours represent a heterogeneous group of entities derived from the manifold structures located in or adjacent to the mediastinum. Due to the occurrence of... (Review)
Review
Mediastinal tumours represent a heterogeneous group of entities derived from the manifold structures located in or adjacent to the mediastinum. Due to the occurrence of some of these tumours in characteristic mediastinal compartments, an anatomical subdivision of the mediastinum in the prevascular (anterior), visceral (middle), and paravertebral (posterior) is helpful for the differential diagnosis. Benign anterior mediastinal tumours linked to an enlargement of the thymic gland mainly consist of thymic cysts and several types of thymic hyperplasia: true thymic hyperplasia, rebound hyperplasia, lymphofollicular hyperplasia, and so-called thymic hyperplasia with lymphoepithelial sialadenitis (LESA)-like features. Mature teratomas, ectopic (para)thyroid tissue, and benign thymic tumours such as thymolipoma or thymofibrolipoma represent further typical tumours of the anterior mediastinum. Pericardial, bronchogenic, or oesophageal duplication cysts predominate in the middle mediastinum, whereas neurogenic tumours and myelolipomas are characteristic findings in the posterior compartment. Vascular tumours, lipomas, adenomatoid tumours, Castleman disease, or mediastinitis are further examples of less frequent tumours or tumorous lesions affecting the mediastinum. This review focuses on benign mediastinal lesions with an emphasis on benign tumours of the thymus. Besides histology, characteristic epidemiological and clinical aspects prerequisite for the correct diagnosis and patient management are discussed.
Topics: Humans; Mediastinum; Mediastinal Neoplasms; Thymus Hyperplasia; Hyperplasia; Thymus Neoplasms
PubMed: 37988262
DOI: 10.1111/his.15088 -
Cell and Tissue Research Sep 2023Serum calcium homeostasis is mainly regulated by parathormone (PTH) secreted by the parathyroid gland. Besides PTH and Gcm2, a master gene for parathyroid... (Review)
Review
Serum calcium homeostasis is mainly regulated by parathormone (PTH) secreted by the parathyroid gland. Besides PTH and Gcm2, a master gene for parathyroid differentiation, many genes are expressed in the gland. Especially, calcium-sensing receptor (CaSR), vitamin D receptor (VDR), and Klotho function to prevent increased secretion of PTH and hyperplasia of the parathyroid gland under chronic hypocalcemia. Parathyroid-specific dual deletion of Klotho and CaSR induces a marked enlargement of the glandular size. The parathyroid develops from the third and fourth pharyngeal pouches except murine species in which the gland is derived from the third pouch only. The development of the murine parathyroid gland is categorized as follows: (1) formation and differentiation of the pharyngeal pouches, (2) appearance of parathyroid domain in the third pharyngeal pouch together with thymus domain, (3) migration of parathyroid primordium attached to the top of thymus, and (4) contact with the thyroid lobe and separation from the thymus. The transcription factors and signaling molecules involved in each of these developmental stages are elaborated. In addition, mesenchymal neural crest cells surrounding the pharyngeal pouches and parathyroid primordium and invading the parathyroid parenchyma participate in the development of the gland.
Topics: Mice; Animals; Parathyroid Glands; Transcription Factors; Organogenesis; Cell Differentiation; Embryonic Development; Thymus Gland; Mammals
PubMed: 37410127
DOI: 10.1007/s00441-023-03785-3 -
Endocrinology Dec 2023
Topics: Humans; Calcium; Vitamin D; Cyclin D1; Parathyroid Glands; Parathyroid Hormone; Vitamin D Deficiency; Carcinogenesis
PubMed: 38104244
DOI: 10.1210/endocr/bqad189