As histologists, you should be familiar with the light microscope. It is generally accepted that in 1674, Anthony van Leeuwenhoek invented the modern light microscope. Though Robert Hooke hand-shaved thin slices of cork to view under a magnifying glass in 1665 (hence the coining of the word “cell”), van Leeuwenhoek perfected the art of grinding and matching lenses. His lenses allowed the visualization of individual cells and bacteria in water droplets, which he called “animalcules”. Van Leeuwenhoek’s optical principles have stood the test of time, and have provided the basis for the light microscopes that we use today. Then, as now, microscopic images are obtained using light that reflects off the object.
Every pathology department and associated histology laboratory must have a chemical monitoring program. It may be part of a larger Chemical Hygiene Plan. Laboratory employees must be kept safe by providing information on dangers, explaining the ways in which employees can protect themselves, and providing annual training to reinforce this information. This is not just a good plan – in most instances, this plan is backed by laws and regulations. This current blog will continue the ideas of the previous one, where we discussed engineering controls such as grossing hoods used in laboratories to provide safe work stations.
Some specimens may be very tiny; on the order of less than 0.1 cm. Some methods employ the use of mesh cassettes, “tea bag” biopsy pouches, sponges, wrapping paper, etc. in order to contain the specimen and prevent it from escaping the tissue processing cassette. A disadvantage of the above methods is that upon embedding, the specimen has to be handled yet again, possibly resulting in additional fragmentation of the tissue, or possibly complete tissue loss.
All laboratory personnel should be aware of and know what personal protective equipment (PPE) they should wear while performing various tasks in the histology laboratory. Employers are responsible for educating laboratory personnel about what hazardous chemicals they might handle, how to handle them safely and what specific protective equipment to wear for each and every task that is performed in the laboratory.
The book “Dermatopathology Laboratory Techniques” should be useful to grossing technicians, physician assistants, pathology / dermatology residents and histotechnicians who require understanding of basic skin anatomy, terminology, methods of fixation, grossing procedures and tissue processing.
This blog is a followup to the previous article “The H&E Stain: Far From Routine”. In that article, the basics of the routine hematoxylin and eosin (H&E) stain were discussed. Now we shall discuss how to trouble shoot the routine H&E and how to ensure a high quality stain, once you have worked with your pathologist to determine the best stain result for your laboratory.
What exactly is a routine “H&E”? And what makes it routine? The first question is easy. “H” stands for ”hematoxylin” and “E” stands for “eosin”. Both are dyes used to stain tissue sections in histology. However, the procedure for correctly applying this combination of stains to tissue sections is far from routine.
Increased awareness of skin cancer has resulted in increased numbers of patients visiting their dermatologists. When warranted, the dermatologist may perform a biopsy of any suspicious lesion and submit it to a pathology laboratory for diagnosis by a pathologist. If the diagnosis is a cancer, the lesion will have to be excised, since the cure for skin cancer is surgical removal of the tumor. For lesions located on the face, head, neck or other cosmetically sensitive areas, the dermatologist may elect to employ the method of Mohs histographic surgery to effect the complete surgical removal of the tumor. This procedure is usually reserved for basal cell carcinoma and squamous cell carcinoma. Malignant melanoma is usually treated with standard elliptical excisions.
In the previous Blog “Dermatopathology 101”, a clear outline of material was provided which ensured the skin’s histology presentation as an organ in the final microscope slide. We discussed basic skin histology, and important aspects of embedding and microtomy.
Dermatopathology is a subject heading in pathology all unto itself. The intrinsic nature of dermatopathology specimens received in a laboratory necessitates a clear understanding of the material due to importance of the skin’s histology presentation as an organ. The goal of the histologist in the preparation of dermatopathology slides is to ensure that the entire area of skin which may contain pathology is represented in the final microscope slide.