Imaging diagnosis
Case 205
【Progress】
Our physician doubted sexual infectious disease. Laboratory test eventually revealed RPR-RU test positive and TPLA-TU 1091 (< 10) leading to diagnosis of syphilis.
【Discussion】
Sexually transmitted disease (STD) other than human immunodeficiency virus (HIV) occurred in 1.1 billion people, whose important complication is infertility and 0.1 million people died worldwide in 2015 (1, 2). Although the type of STD is known to be more than 20, the main STDs are five according to the higher occurrence in Japan (3): Chlamydia, Herpes simplex II, Gonorrhea, genital warts (condyloma) and syphilis. Other imperative STDs are HIV, and papilloma virus (subtype 16, 18) which causes uterine cervical cancer. Genital warts caused by papilloma virus (subtype 6, 11) does not lead to uterine cancer, implying to be benign. Namely, bacterial STDs include chlamydia, gonorrhea and syphilis. Viral STDs include herpes simplex II, genital warts (condyloma) and HIV. Parasite STD includes trichomoniasis. Syphilis patients increased nearly ten times more in 2019 than them in 2000 (3). Syphilis infects most to young ladies of twenties and males of twenties to forties in Japan.
Treponema pallidum is the gram negative bacteria causing syphilis. Its configuration is a helical shaped, indicating spirochete bacteria. It infects to human only via sexual activity. When Treponema pallidus infects to human and thereafter no treatment is given, syphilis symptoms appear with three phases. The first phase appears after around two to six weeks later as an erosion called chancre sized less than 3cm at penis, vagina, rectum or mouth (4), where treponema pallidum entered. Because of painless sore, the infected person often unnoticed it. The second phase appears one to three months after as systematic reddish eczema or warts. Thereafter, no marked symptoms appear for couple of years, calling latent phase. The third phase appear in 15 to 40 % of patients following the latent phase average 15 years later as gums formation which means tumor-like balls of inflammation (4). It appears systemically: brain, spinal cord (Tabes dorsalis), aorta, skin.
Lymph fluid flow to inguinal nodes from not only lower extremities but also from skin surface organ in the pelvis such as vagina, penis and anus. For example, inguinal nodes are regional (sentinel) lymph node for vaginal cancer, penile cancer and anal cancer (5, 6). Then, in case of radiotherapy for cancers originated from these sites, inguinal node should be included in the radiation field with primary tumor.
In case of STDs, when microorganisms such as bacteria, virus or parasite, regional or sentinel nodes infect to vagina, penis, or anus should be bilateral inguinal node. Regional lymph nodes swell 7 to 10 days after chancre formation and continue for 3 to 6 weeks (4). In our case, she suffered from persistent fever at night. Her urine test revealed including white blood cells. CT showed bilateral swollen inguinal lymph nodes. Laboratory test revealed high values of TPLA-TU 1091, implying diagnosis of syphilis. When unknown fever, persistent presence of white blood cells in urine test, and swollen inguinal lymph nodes are found, STDs should be listed for differential diagnosis.
【Summary】
We present a nineteen-year-old female suffering from persistent fever at night for 10 days. Urine test revealed WBC 3+, 50-99 (< 4). Laboratory test revealed CRP 5.6 mg/dL. Abdomen contrast-enhanced CT depict swollen bilateral inguinal lymph nodes & external iliac lymph nodes. Eventually, it revealed TPLA-TU 1091 (< 10) leading to diagnosis of syphilis. It is borne in mind that syphilis is the 5th place of the sexually transmitted diseases (STD) following chlamydia, simple herpes type II, gonorrhea and genital warts (condyloma). Treponema pallidus is a gram-negative bacteria causing syphilis. The clinical stage of syphilis is categorized; first phase, formation of painless erosion; second phase formation of systemic reddish eczema or warts; latent term average 14 years: late phase, formation of gums, tumor like balls of inflammation. Inguinal nodes are regional lymph node for vaginal cancer, penile cancer and anal cancer. Then, inguinal nodes can be sentinel nodes for STD. Namely, when youth present in the hospital for unknown fever with positive urine test and bilateral swollen lymph nodes, STD should be listed for differential diagnosis.
【References】
1."Sexually transmitted infections (STIs) Fact sheet N°110". who.int. November 2013. Archived from the original on 25 November 2014. Retrieved 30 November 2014.
2.Wang H, et al. (GBD 2015 Mortality Causes of Death Collaborators) (October 2016). "Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015". Lancet. 388 (10053): 1459–1544.
3.Japan Ministry of Health, Labor and Welfare https://www.mhlw.go.jp/topics/2005/04/tp0411-1.html
4.Kent ME, et al. "Reexamining syphilis: an update on epidemiology, clinical manifestations, and management". Annals of Pharmacotherapy.2008;42: 226–36.
5.Zhu Y, et al. "Prospectively packaged ilioinguinal lymphadenectomy for penile cancer: the disseminative pattern of lymph node metastasis". J. Urol. 2009; 181 (5): 2103–8.
6.Nicholas B et al. "Inguinal lymph nodes: size, number, and other characteristics in asymptomatic patients by CT". Surgical and Radiologic Anatomy. 2014; 36 (10): 1051–1055.
2020.9.16