Atelectasis chronic inflammation, scarring, and bronchiectasis. In rounded atelectasis (Folded lung or Blesovsky syndrome), an outer portion of the lung slowly collapses as a result of scarring and shrinkage of the membrane layers covering the lungs (pleura), which would show as visceral pleural thickening and entrapment of lung tissue. This produces a rounded appearance on x-ray that doctors may mistake for a tumor. Rounded atelectasis is usually a complication of asbestos-induced disease of the pleura, but it may also result from other types of chronic scarring and thickening of the pleura. Treatment is directed at correcting the underlying cause. Post-surgical atelectasis
Ultimopharyngeal body Ultimopharyngeal body The ultimopharyngeal body or ultimobranchial body or ultimobranchial gland is a small organ found in the neck region of many animals. In humans, the ultimobranchial body is an embryological structure that gives rise to the calcitonin-producing cells—also called parafollicular cells or C cells—of the thyroid gland. In humans, this body is a derivative of the ventral recess of the fourth pharyngeal pouch (technically fifth, but that one is rudimentary and merges with the fourth). The cells that give rise to the parafollicular cells are actually derivatives of the endoderm. These cells migrate and associate with the ultimopharyngeal body