Nodular Lymphoid Hyperplasia of the Colon in an Adult Patient after Covid-19 Infection: A Case Report and Literature Review

Nodular lymphoid hyperplasia of the colon (NLHC) is an uncommon pathology in adults. The disease can be asymptomatic and discovered incidentally or symptomatic, which is often manifested by abdominal pain and motility disorders (diarrhea, constipation). The clinical presentation can also be alarming with rectal bleeding and obstructive symptoms that may be misinterpreted as a neoplastic process. In this paper, we report the case of a 58-year-old female patient with a previous history of appendicetomy. She presented with persistent abdominal pain, chronic constipation and black colored stools, following Covid-19 infection. The physical examination was unremarkable. Colonoscopy examination found a bulging, non-ulcerated mass, measuring 3.5 cm in greatest dimension, located at the right colic angle. Thoraco-abdomino-pelvic computed tomography was performed and showed right colonic wall thickening and enhanced nodule formation. Furthermore, metastatic localization was not detected. After a multidisciplinary meeting, a laparotomy with right hemicolectomy was performed. Histopathological examination of the surgical specimen revealed nodular lymphoid hyperplasia with CD20+, CD5−, CD10+ and BCL2− phenotype on immunohistochemistry. Besides, lymphocytes in interfollicular area are CD3+ T cells. Patient outcome was favorable after surgery and no additional treatment was necessary. Nodular lymphoid hyperplasia of the colon is a benign process whose endoscopic appearance can sometimes raise suspicion of malignancy. The diagnosis can only be established by histological evaluation. Immunohistochemistry is also essential to confirm the diagnosis and to rule out low-grade lymphoma. Clinical evolution is often favorable. However, endoscopic follow-up is necessary in all cases.