VANCOUVER (FRONTLINE MEDICAL NEWS)Dr. Curtis T. Thompson is on a mission: to improve the often-shoddy quality of nail biopsy specimens submitted to pathologists.

No standardized protocols for nail specimens exist. The quality of pathologic diagnosis often suffers as a result, Dr. Thompson said at the World Congress of Dermatology.

“What often happens is the nail specimens get put into a bottle of formaldehyde, they float around and get torn up, and then when they come to the lab, we have no idea what’s proximal and dorsal. This is an issue. We’re all used to just putting a nail specimen in a bottle and sending it away, so all the grossing happens in the laboratory. What I submit to you is you need to be more involved in the grossing side so the specimen can be properly processed,” said Dr. Thompson, a dermatopathologist in group practice in Tigard, Ore.

He added that clear and concise guidelines for standardized specimen submission are needed, and he offered several specific suggestions regarding the orientation of the tissue and securing it for transport.

“Careful submission of tissue specimens is of great importance and allows for better diagnostics,” Dr. Thompson stressed. “There’s really nothing more terrifying than to be told you’re being sent a pigmented lesion and then not being able to find anything at all in the specimen. You really worry that it’s ended up in the trash can through leveling. This is why dermatopathologists don’t want to read nail biopsies very much.”

When a nail specimen is submitted properly, such mix-ups become “almost impossible,” according to the dermatopathologist.

Dr. Thompson borrowed one of his key ideas on efficient handling of nail specimens from opthalmologic pathology. Ophthalmologists routinely send delicate tissue segments and margins from the operating room, and they do so with consistent success because they place the segments on a cartoon of the eye so the pathologist can see exactly where the tissue was located on the patient.

Dermatologists and surgeons can do the same after printing out a sheaf of nail diagrams gratis at the Website for Dr. Thompson’s dermatopathology practice.

The rest of the necessary equipment is similarly simple and readily obtainable from any pathology laboratory, which routinely purchases small plastic cassettes by the tens of thousands for handling of tissue specimens.

“You don’t need to go out and buy them; just ask the lab you work with to send over 10 or so,” Dr. Thompson advised.

The cassette comes with a small fitted sponge to be placed over the tissue to keep it securely in place on the nail diagram rather than floating off. Ink one end of the specimen using the wooden end of a cotton-tip applicator so the lab knows which end is proximal and which is distal. The wooden tip provides more precise inking than the cotton-tip end. Then place the closed cassette in a larger bottle of formaldehyde for shipping.

One more thing: Separate the nail plate from the nail bed or matrix whenever possible, and place them in separate cassettes. Lab technicians typically devote a lot of attention to trying to get the nail plate to stick to a slide, but the diagnostic material is usually present in the nail bed or matrix, and keeping those soft tissues separate makes it less likely they’ll get lost in the shuffle.

“I recommend putting the nail plate cassette and the lesional tissue in the same bottle because then you don’t have two specimens with double the charge for the patient,” Dr. Thompson said.

He reported having no relevant financial conflicts.



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