Rectal tonsil associated with Epstein–Barr virus

Reactive polypoid proliferation of lymphoid tissue has been described along the gastrointestinal tract [1]. Endoscopically, when a non-lymphomatous lymphoid reaction resembling tonsillar tissue is present in the rectum, the polyp is named as “rectal tonsil”. Few cases have been reported in the literature [1] [2], and the etiology of this rare condition is unknown [3] [4] [5].

Here we describe the case of a 58-year-old man referred to our center with a 6-month history of fresh bleeding from the rectum. A colonoscopy was performed and a delineated round, reddish, nodular aggregate measuring 4 × 3 × 3 cm was found ([Fig. 1]). A polypectomy was performed ([Fig. 2]), and histological examination ([Fig. 3]) revealed infiltration of mucosa, submucosa, and lamina propria of the colon by numerous lymphoid follicles. Immunohistochemical markers were positive for CD20 + (B cells), and intraepithelial lymphocytes were positive for CD3 + (T cells). Epstein–Barr virus encoded RNA in situ hybridization was positive ([Fig. 3 f]).

Fig. 1 a Colonoscopy revealed a well-delineated, round, reddish, nodular aggregate measuring 4 × 3 × 3 cm, with follicles resembling the tonsils. b High definition colonoscopy using a digital filter (i-Scan 2, Pentax) emphasized the nodular component of the lesion.

Fig. 2 a Macroscopic aspect of nodular aggregate with follicles. b Histological view of nodular and diffuse aspect using hematoxylin and eosin (H&E) stain. c Macroscopic histological view using CD45 immunoreaction.

Fig. 3 a Residual colonic crypts; hematoxylin and eosin (H&E) stain, × 200. b Reactive lymphocytes and isolated immunoblasts (H&E stain, × 800). c Binucleate reactive Reed–Sternberg-like cells (H&E stain, × 800). d Positive CD20 immunoreaction. e Positive CD3 immunoreaction. f Epstein–Barr virus-encoded RNA was positive (in situ hybridization for Epstein–Barr virus).

At 1- and 6-month follow-up, there was no recurrence of the lesion in the rectum.

This case represents the first case of rectal tonsil associated with Epstein–Barr virus infection.

Endoscopy_UCTN_Code_CCL_1AD_2AZ

• References

• 1 Farris AB, Lauwers GY, Ferry JA, Zukerberg LR. The rectal tonsil: a reactive lymphoid proliferation that may mimic lymphoma. Am J Surg Pathol 2008; 32: 1075-1079
• 2 O’Leary AD, Sweeney EC. Lymphoglandular complexes of the colon: structure and distribution. Histopathology 1986; 10: 267-283
• 3 Lloyd J, Darzi A, Teare J, Goldin RD. A solitary benign lymphoid polyp of the rectum in a 51 year old woman. J Clin Pathol 1997; 50: 1034-1035
• 4 Agaimy A, Mudter J, Märkl B, Chetty R. Cytomegalovirus infection presenting as isolated inflammatory polyps of the gastrointestinal tract. Pathology 2011; 43: 440-446
• 5 Cramer SF, Romansky S, Hulbert B et al. The rectal tonsil: a reaction to chlamydial infection?. Am J Surg Pathol 2009; 33: 483-485