From the pathologist: review of sexual behaviors should be a routine component of clinical histories

The Histopathology of Anorectal Neisseria gonorrhoeae Infection

OBJECTIVES

Neisseria gonorrhoeae infection of the anorectal tract is often asymptomatic and infrequently biopsied, but pathologists can be tasked with identifying the histologic features of possible infection. The study was undertaken to better characterize clinical and morphologic features of confirmed anorectal gonococcal infection.

METHODS

From 2011 to 2020, 201 positive gonococcal nucleic acid amplification testing samples from 174 patients collected from the distal colorectum and/or anus were matched to eight patients with concurrent biopsy specimens of the distal anorectum. Complete demographic, clinical, and infectious information was collected for each biopsied patient. The histomorphologic features of each biopsy were systematically tabulated.

RESULTS

All eight gonococcal cases were obtained from men who have sex with men. Each case showed at least mild acute inflammation with moderate activity identified in one case with concurrent cytomegalovirus infection. Intense lymphoplasmacytic infiltration was not commonly seen (two of eight). Half of the cases showed mucosal ulceration, and seven of eight cases demonstrated lymphoid aggregates.

CONCLUSIONS

The microscopic features are mild compared with other well-described types of infectious proctitis, with most cases displaying mild acute inflammation and scattered lymphoid aggregates. These findings highlight the importance of obtaining a complete patient history and recommending additional infectious workup even when only subtle changes are present.

Lymphogranuloma venereum (LGV) of the anorectum: evaluation of clinicopathological associations and the utility of a novel RNA in-situ hybridisation stain

AIMS

Recent studies from multiple global regions have reported a resurgence of lymphogranuloma venereum (LGV) proctitis, which is caused by Chlamydia trachomatis (CT). LGV proctitis is histologically indistinguishable from other forms of sexually transmitted proctitis and is difficult to differentiate from inflammatory bowel disease. While immunohistochemical stains are available for syphilis, there is no commonly available stain for the tissue identification of CT.

MATERIALS AND METHODS

From 200 positive CT nucleic acid tests (NAT) from anorectal swabs, we identified 12 patients with biopsies collected from the distal colorectum or anus within 90 days of the positive NAT. We collected basic demographic information and tabulated clinical and histological findings. We examined the performance of a novel RNA in-situ hybridisation (ISH) stain targeting CT 23s rRNA on these 12 cases and 10 controls from the anorectum.

RESULTS

All 12 patients were male; nine were HIV+, two had concurrent gonococcal infection, one had concurrent syphilis and one had cytomegalovirus co-infection. The majority of biopsies (11 of 12) showed mild or moderate acute inflammation, had a prominent lymphoplasmacytic infiltrate (eight of 11) and lacked marked crypt distortion (10 of 10). The RNA ISH stain was positive in 10 of 12 cases (sensitivity 83%). One case showed equivocal staining. No controls showed definitive positive staining (specificity 100%). One had equivocal staining.

CONCLUSION

Our series showed that anorectal LGV had similar histological findings to those of prior STI proctitis series predominantly comprised of syphilis. The novel RNA ISH stain was sensitive and specific and may show utility in differentiating types of STI proctitis.