Leprosy Mailing List – August 14, 2018
Ref.: (LML) Manifest against the implementation of U-MDT
From: David Scollard, Baton Rouge, USA
Dear Pieter,
Dr. Shetty's comments (LML Aug 7,2018) have raised the question of the relative merits of elliptical vs punch biopsies for the diagnosis of HD. The elliptical biopsy will often be larger and thus provide more material for histopathological review. This would be preferable if all other factors were equal.
However, in our experience, physicians and surgeons taking an elliptical skin biopsy often angle the blade from the margin of the biopsy at the surface toward the center at the deepest point, so that the specimen is a 'wedge'. The result is that the extent of the specimen in the deep dermis is small, and this is where cutaneous nerves are most easily found and evaluated.
A punch biopsy, on the other hand, is as wide at full depth as it is at the surface, and gives a proportionally better sample of the deep dermis. As long as emphasis is maintained on obtaining a full-thickness specimen from an active margin of a lesion, a punch biopsy usually provides a very good sample regardless of the skill and experience of the person who performs it.
In my 25 years of experience at the National Hansen's Disease Programs (USA), we found that 4 mm or 6 mm punch biopsies provided excellent material for histopathological diagnosis. In recent years we also found that these specimens provided sufficient additional material for PCR amplification of M. leprae DNA for genotyping.
Best regards,
David Scollard
NHDP (Retired)
LML - S Deepak, B Naafs, S Noto and P Schreuder
LML blog link: http://leprosymailinglist.blogspot.it/
Contact: Dr Pieter Schreuder << editorlml@gmail.com
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