Contaminant Treponema-Positive Bacteria in Cutaneous Biopsies With an Infiltrate Rich in Plasma CellsFernandez-Flores, Angel MD, PhDAmerican Journal of Dermatopathology: June 2011 - Volume 33 - Issue 4 - pp 415-417 doi: 10.1097/DAD.0b013e3181e84e4b Letter to the Editor Author Information Author Information The Service of Cellular Pathology, Clinica Ponferrada, Ponferrada, Spain Article OutlineTo the Editor: Since we published a previous article on possible pitfalls of the immunohistochemical method for Treponema,1 we have seen some other interesting examples that we would like to report. It is well known that when tap water is used to wash the slide (instead of distilled water), in many occasions, it is possible to observe bacteria on the slide, in the areas that surround the tissue of the biopsy. It is less known, perhaps, that distilled water can also be contaminated by bacteria. We have observed how these bacteria are immunostained many times with the antibody for Treponema. This fact would be merely anecdotal, except for the fact that on some occasions, such bacteria can be superimposed to the tissue section. Figure 1 is an example of this. It shows a cutaneous biopsy with a dermal inflammatory infiltrate rich in plasma cells. Due mainly to the presence of these cells, immunostaining for Treponema was requested and, some positive bacteria were evidenced on the epidermis. Some of them were even the same length as Treponema (between 6 and 20 μm), although they were obviously easily distinguishable from Treponema due to their morphology that was not spiralled. The diagnostic clue was readily evident from looking at the slide out of the tissue, where the same types of bacteria were found (Fig. 2). Figure 1 Figure 2 In many cutaneous biopsies with an inflammatory infiltrate rich in plasma cells the clinical history can be nondeterminant for the diagnosis as “syphilitic lesion.” Thus, it is crucial to take into account that there can be “transient” bacilli on the epidermis of the biopsy. This, therefore, can induce to mistakes if we do not consider their nonspiral morphology. Angel Fernandez-Flores, MD, PhD The Service of Cellular Pathology, Clinica Ponferrada, Ponferrada, Spain Back to Top | Article Outline REFERENCE1. Fernandez-Flores A. Immunostaining for Treponema pallidum: caution in its evaluation. Am J Dermatopathol. In press. Cited Here... © 2011 Lippincott Williams & Wilkins, Inc. Article Outline REFERENCE Source Contaminant Treponema-Positive Bacteria in Cutaneous Biopsies With an Infiltrate Rich in Plasma Cells The American Journal of Dermatopathology. 33(4):415-417, June 2011. Full-Size Email + Favorites Export View in Gallery Email to a Colleague Colleague's E-mail is Invalid Your Name: (optional) Your Email: Colleague's Email: Separate multiple e-mails with a (;). Message: Thought you might appreciate this item(s) I saw at The American Journal of Dermatopathology. Send a copy to your email Your message has been successfully sent to your colleague. Some error has occurred while processing your request. Please try after some time. Add Item(s) to: An Existing Folder A New Folder Folder Name: Description: The item(s) has been successfully added to "".