Appearance
Simple CWP is marked by the presence of 1–2mm nodular aggregations of anthracotic macrophages, supported by a fine collagen network, within the lungs. Those 1–2mm in diameter are known as coal macules, with larger aggregations known as coal nodules. These structures occur most frequently around the initial site of coal dust accumulation — the upper regions of the lungs around respiratory bronchioles. The coal macule is the basic pathological feature of CWP, and has a surrounding area of enlargement of the airspace, known as focal emphysema.
Continued exposure to coal dust following the development of simple CWP may progress to complicated CWP with progressive massive fibrosis (PMF), wherein large masses of dense fibrosis develop, usually in the upper lung zones, measuring greater than 1 cm in diameter, with accompanying decreased lung function. These cases generally require a number of years to develop. Grossly, the lung itself appears blackened. Pathologically, these consist of fibrosis with haphazardly-arranged collagen and many pigment-laden macrophages and abundant free pigment. Radiographically, CWP can appear strikingly similar to silicosis. In simple CWP, small rounded nodules (see ILO Classification) predominate, tending to first appear in the upper lung zones. The nodules may coalesce and form large opacities (>1 cm), characterizing complicated CWP, or PMF.
Read more about this topic: Coalworker's Pneumoconiosis
Famous quotes containing the word appearance:
“Hence, the less government we have, the better,—the fewer laws, and the less confided power. The antidote to this abuse of formal Government, is, the influence of private character, the growth of the Individual; the appearance of the principal to supersede the proxy; the appearance of the wise man, of whom the existing government, is, it must be owned, but a shabby imitation.”
—Ralph Waldo Emerson (1803–1882)
“To educate the wise man, the State exists; and with the appearance of the wise man, the State expires. The appearance of character makes the state unnecessary. The wise man is the State.”
—Ralph Waldo Emerson (1803–1882)
“What! Would you make no distinction between hypocrisy and devotion? Would you give them the same names, and respect the mask as you do the face? Would you equate artifice and sincerity? Confound appearance with truth? Regard the phantom as the very person? Value counterfeit as cash?”
—Molière [Jean Baptiste Poquelin] (1622–1673)