• Jena Martin MD

Diagnosis Decision: The Great Imitator. ⠀

Great Moments in PathologyTM *

Who is The Great Imitator? (I thought this term was highly specific for Syphilis. But it turns out, diseases that have systemic effects and a variety of symptoms can all be called this. Diseases like Lymes, Lupus and Syphilis have each been called The Great Imitator. )

In the clinic the manifestations of Syphilis can look like many other diseases; so too under the microscope. If there's a rash with a pattern I can't explain, or an alopecia (biopsy performed to determine the cause of balding) that has inflammation but no cogent explanation, I'll order a stain for Treponema pallidum. Every dermatopathologist has a story about some case that has gone undiagnosed in the clinic, or explained as some other condition, that when examined and stained for Treponema, is finally understood to be the rash of Syphilis.

🔬Here is one such case:

This is a dermatitis. Although not specific, the elongated rete ridges and numerous plasma cells make me suspicious for syphilis...

🔬...a suspicion that is confirmed, in florid fashion, with the next image, a high power look at our immunohistochemical stain for T. pallidum:

The red squiggly lines are the corkscrew-shaped bacteria, squeezed between the keratinocytes.

Syphilis has such an interesting life cycle, typically:⠀ ⠀ 🥚(Primary) Starts as a painless (!) ulcer on the genitals or mouth.⠀ ⠀ ⠀ 🐣(Secondary) Reawakens in a few weeks as a scaly and bumpy rash (papulosquamous) - looking like many other rashes except unique in that it appears on the palms and/or soles.⠀ ⠀ ⠀ 🧟‍♂️(Tertiary) Disappears... hiding out in the latent phase. When it reawakens, it can erode bones, destroy noses, mouths and eyes, cause mental illness and organ damage.⠀ ⠀ Sadly, Syphilis is on the rise: ⠀ 🚨 In 2017, a total of 30,644 cases of syphilis (both primary and secondary) were reported in the United States, yielding a rate of 9.5 cases per 100,000 population.⠀ ⠀ 🚨 This rate represents a 10.5% increase compared with 2016 (8.6 cases per 100,000 population); and a 72.7% increase compared with 2013 (5.5 cases per 100,000 population).⠀ ⠀ (Numbers from CDC website; lots of good information available here if you have concerns: https://www.cdc.gov/std/syphilis/default.htm) ⠀ So be aware, but don't panic. Syphilis isn't easy to get - it's spread through sexual contact. It can't be spread by using the same toilet, bathtub, clothing or eating utensils, or from doorknobs, swimming pools or hot tubs.⠀It's easy to test for and easy to treat if caught early. ⠀

*TM - This phrase: "Great Moments in Pathology" is my personal term for those amazing cases where we, the pathologist, clinches an unexpected diagnosis. It's a fist-pumping, celebratory moment when one recognizes these rarities. A Great Moment.