Lymphogranuloma venereum presenting as a giant rectal ulcer with inguinal lymphadenitis: a case report

Abstract

Anorectal lymphogranuloma venereum (LGV) can mimic rectal malignancy, but diagnosis may be challenging when LGV-specific serovar testing is unavailable. A 26-year-old man who has sex with men presented with hematochezia and increased bowel movement frequency. Colonoscopy revealed a large deep rectal ulcer with mucopurulent exudate, and pelvic magnetic resonance imaging showed rectal wall thickening with regional lymphadenopathy, raising concern for rectal cancer. Histopathology showed inflammatory changes without malignancy. Rectal secretion testing was positive for Chlamydia trachomatis RNA, and the patient was clinically diagnosed with probable anorectal LGV. Oral doxycycline 100 mg twice daily for 21 days led to marked ulcer regression at 3 weeks and near-complete mucosal healing by 6 weeks. This case highlights the importance of considering sexually transmitted proctitis in young men who have sex with men patients with atypical rectal ulcers.

Introduction

Chlamydia trachomatis is a common sexually transmitted intracellular pathogen [1, 2]. Lymphogranuloma venereum (LGV), caused by invasive C. trachomatis serovars L1–L3, may present as severe proctitis, rectal ulceration, and lymphadenitis in men who have sex with men (MSM) [3–5]. Because its endoscopic and radiological findings can resemble inflammatory bowel disease or rectal malignancy, delayed diagnosis may lead to unnecessary invasive treatment [3, 6, 7]. We report a probable anorectal LGV case presenting as a giant rectal ulcer with inguinal lymphadenitis.

Case presentation

A 26-year-old MSM was admitted with a 1-month history of hematochezia and increased bowel movement frequency after recent same-sex intercourse. He had low-grade fever, slightly elevated inflammatory markers, enlarged inguinal lymph nodes, and rectal wall thickening ~3 cm from the anal verge on digital rectal examination. Tests for syphilis, human immunodeficiency virus (HIV), Mycobacterium tuberculosis-specific cellular responses, and Treponema pallidum-specific staining were negative.

Pelvic magnetic resonance imaging (MRI) showed diffuse lower rectal wall thickening with multiple surrounding enlarged lymph nodes, initially raising concern for rectal malignancy (Fig. 1a). Colonoscopy revealed extensive mucosal erosion, inflammatory hyperplasia, mucopurulent exudate, and a large deep ulcer involving about half of the rectal circumference (Fig. 1b). However, the lesion appeared predominantly inflammatory rather than mass-forming. Rectal biopsy showed inflammatory cell infiltration, necrotic exudate, and histiocytic hyperplasia, without malignant epithelial cells, dysplasia, or tumor-forming architecture. Typical features of inflammatory bowel disease, such as chronic crypt architectural distortion, basal plasmacytosis, or diagnostic granulomas, were absent. Left inguinal lymph node biopsy demonstrated chronic granulomatous inflammation with focal suppuration, favoring infectious lymphadenitis over metastatic disease.

Rectal secretions were positive for Ureaplasma urealyticum and C. trachomatis RNA. LGV-specific L1–L3 serovar testing was unavailable; therefore, a clinical diagnosis of probable anorectal LGV was made based on MSM history, severe ulcerative proctitis, inguinal lymphadenopathy, positive rectal C. trachomatis RNA, exclusion of malignancy and common alternative causes, and subsequent treatment response [7–9]. Oral doxycycline 100 mg twice daily was administered for 21 days. Colonoscopy after 3 weeks showed marked ulcer regression (Fig. 2a), and near-complete mucosal healing was observed after 6 weeks (Fig. 2b). Two months after treatment, rectal secretion tests for U. urealyticum and C. trachomatis RNA were negative.

Discussion

This case emphasizes that sexually transmitted proctitis should be considered in young MSM patients with atypical rectal ulcers. Rectal wall thickening, hematochezia, a large ulcer, and lymphadenopathy can mimic rectal cancer, and previous reports have described LGV presenting as ulcerative or mass-like rectal lesions [6, 7]. Nevertheless, diffuse inflammatory mucosal changes, absence of a discrete tumor, negative histopathology for carcinoma, and response to doxycycline favored infection in this patient.

The diagnosis should be interpreted as probable rather than microbiologically confirmed LGV because LGV-specific serovar identification was not performed. Ideally, C. trachomatis nucleic acid amplification testing should be followed by LGV-discriminatory molecular typing [5, 8]. In clinical practice, probable LGV may be diagnosed when severe anorectal symptoms, inguinal lymphadenopathy, positive rectal C. trachomatis testing, and epidemiological risk factors are present. The recommended treatment is doxycycline 100 mg twice daily for 21 days [5, 9].

Differential diagnosis includes non-LGV anorectal chlamydial infection, gonococcal proctitis, syphilitic proctitis, herpes simplex virus proctitis, cytomegalovirus proctitis, amebic colitis, tuberculosis, inflammatory bowel disease, and rectal cancer [9]. Inguinal lymphadenopathy was an important clue: although it may be misinterpreted as metastatic disease, lymphatic involvement, and lymphadenitis are characteristic of LGV [4, 5]. Thus, enlarged inguinal nodes in a sexually active MSM patient should prompt sexual history-taking and targeted STI testing.

The concomitant U. urealyticum positivity should be interpreted cautiously because it may represent colonization [10]. Its role in causing a giant rectal ulcer is uncertain, and the overall clinicopathological picture was more consistent with C. trachomatis-associated proctitis/probable LGV. Because doxycycline is active against some Ureaplasma infections, post-treatment negativity does not prove that U. urealyticum was the primary pathogen.

Conclusion

Probable anorectal LGV can mimic rectal cancer or inflammatory bowel disease. In young MSM patients with giant rectal ulcers, rectal wall thickening, and inguinal lymphadenopathy, early rectal C. trachomatis testing and clinicopathological correlation are essential to avoid misdiagnosis and unnecessary surgery.

Acknowledgements

Y.D.L. is the first author of this study, and M.J.Z. and Z.Y.L. are the co-corresponding authors. The authors would like to thank all the people involved in this work.

Author contributions

Y.D.L. and X.F.Z. contributed to the conceptualization and investigation of this study. Y.D.L. performed the data analysis and drafted the original manuscript. X.F.Z., Z.Y.L., and M.J.Z. were involved in methodology, resources, and data curation. Z.Y.L. and M.J.Z. provided supervision, project administration, and critical revision of the manuscript for important intellectual content. Z.S. acquired the necessary funding. All authors have read and approved the final manuscript, and each author agrees to be held accountable for all aspects of the research.

Conflicts of interest

None declared.

Funding

This work was supported by The Construction Fund of Key Medical Disciplines of Hangzhou.

Data availability

The data involved in this study are available from the corresponding author upon reasonable request.

Ethics approval and consent to participate

This study was approved by the Ethics Committee of the Hangzhou Third People’s Hospital.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

References