Round Bodies Detected by Treponema pallidum Immunohistochemical Stain in Two Cases of Cutaneous Syphilitic Gummata.

ABSTRACT: Tertiary syphilis may present a diagnostic challenge due to negative nontreponemal serologies in up to 30% of cases and frequent lack of identifiable spirochetes on histopathology or other direct detection tests. We report 2 cases of round bodies staining with Treponema pallidum immunohistochemistry by light microscopy in biopsies from cutaneous syphilitic gummata. In 1 case, the finding was validated 3 times by 2 independent laboratories; in the other case, T. pallidum was detected by polymerase chain reaction in the biopsy sample. Spirochete round bodies have previously been reported in the setting of electron microscopy and fluorography, but to the best of our knowledge, have not been reported by light microscopy in a routine skin biopsy. Although the clinical implications are unclear, this may represent a helpful new paradigm for the diagnosis of tertiary syphilis.

Secondary syphilis with extra-genital condyloma lata: A case report and review of the literature.

BACKGROUND: Syphilis is known as the "great imitator" because of its polymorphic clinical manifestations. Condyloma lata are an uncommon mucocutaneous manifestation of secondary syphilis, generally localized in intertriginous areas, such as the genitals and anus. Extragenital localization of condyloma lata is considered unusual. METHODS: A case study of extra-genital condylomata is presented. To contextualise the case, a literature review of extra-genital condylomata lata was subsequently undertaken. The authors searched MEDLINE/PubMed, Scopus and Excerpta Medica/EMBASE English-language sources using the following keywords: "condyloma lata", "condylomata lata", and "condyloma latum". RESULTS: Thirty-five papers (from 1940 to 2021) describing an extra-anogenital localization of condyloma lata were found and are summarized in Table 1. Patients were mainly males (82.1%), with a mean age of 31.9 years. Most of them showed other manifestations of secondary syphilis (53.9%). In a minority of cases (39.0%), concomitant anogenital condyloma lata were present, thus making the diagnosis easier. The toe web localization was the most documented (26.2%) followed by the oral cavity (23.8%). CONCLUSION: In the presence of extra-genital condyloma lata, the differential diagnosis is not always clear, especially when no other muco-cutaneous lesions are observed. In the case of eroded or wet lesions involving any cutaneous fold, associated or not with other cutaneous manifestations, a sexual history should be obtained, and syphilis must be considered.