Intestinal Spirochetosis Presenting as a Polyp

Abstract

Purpose: A 66 y/o male presented for a screening colonoscopy. The patient was clinically asymptomatic. The colonoscopy showed a polyp in the cecum and splenic flexure, respectively. Histologically, both specimens revealed spirochetosis in a background of hyperplastic glandular changes with mild inflammatory changes. Human intestinal spirochetosis affects the mucosa of the large intestine where extensive colonization of the epithelial layer by spirochetes occurs. The term “false brush border” was based on the pattern of arrangement along the colonic mucosa. Spirochetes are characterized as gram negative bacteria that travel via flagella through fluid. The term intestinal Spirochetosis was first coined by Harland and Lee in 1967. The spirochetes involved are of the Brachyspira species, with various subspecies present in the human host. Infection with these spirochetes is via the fecal-oral route and thus the host's personal hygiene practices,diet, sexual practices (especially in homosexual males) and immune status are factors to acquiring the condition. Patients infected with intestinal spirochetosis are usually asymptomatic. Cases have been reported of patients presenting with bleeding and diarrhea with more drastic symptoms being found in homosexual men. The condition can be misdiagnosed, especially in the outpatient setting. The organisms are classically found along the surface of intestinal epithelium with superficial penetration into the crypts. Occasionally cell membrane destruction and invasion occur resulting in organisms in intracellular spaces. The incidence has been growing especially in HIV/homosexual population. This raises the question of need for future screening measures. We report an atypical case in which IS presented in a polypoid form. Review of the literature supports the fact that this case is one of three to report a polypoid presentation of intestinal spirochetosis. In our patient early diagnostic measures did not provide evidence for relationship of IS. Furthermore, the patient had not reported any alteration in bowel habits or weight loss. Management of the disease is controversial. Usually infiltration beyond the mucosa is associated with GI symptoms, and thus the use of antibiotics can be considered in this setting. Another thought is to treat conservatively since the organisms may be non-pathogenic.Figure: Extensive colonization of the epithelial layer by the spirochetes - false brush border; Gross polyp lesion.