Apr 28 2009

Riedel thyroiditis

Reidel thyroiditis

We talked a bit about thyroiditis yesterday (see 4/27/09 post). Here’s another kind of thyroiditis: fibrosing (or Riedel) thyroiditis. This one is totally different than subacute granulomatous thyroiditis. In fibrosing thyroiditis, the thyroid becomes overrun by fibrous tissue (guess that’s why they picked that name). For some unkown reason, fibroblasts just start proliferating and laying down collagen. In the picture above, there is one pathetic-looking residual follicle, surrounded by lymphocytes, in a sea of fibrotic tissue. As the disease progresses, the thyroid becomes a rock-hard, woody mass. If it gets big enough, it can compress some of the important structures in the neck, like the trachea, and it may need to be removed.

no comments   |  tags: , , | posted in Endocrine pathology, Thyroid pathology

Apr 10 2009

Reticulin vs. collagen

 

There are some terms in pathology that are used interchangeably – but shouldn’t be. “Reticulin” and “collagen” are two of these terms. Reticulin fibers are the same thing as type III collagen. They are fine, delicate fibers made by fibroblasts. There are other types of collagen (types I, II, and IV are the main ones, but there are more) that have different appearances and are found in different places. Type I collagen is the main component of bone, type II is the main component of cartilage, and type IV is the main component of basement membranes.

 

 

no comments   |  tags: | posted in General pathology