A Rare Case of Diffuse Nodular Lymphoid Hyperplasia With Rectal Involvement.

Nodular lymphoid hyperplasia (NLH) is characterized by the growth of multiple discrete small submucosal nodules specifically confined to the lamina propria and superficial submucosa layers of the intestinal wall. Gastric and rectal involvement of NLH is exceedingly rare. To date, few case reports have described diffuse NLH presenting with multiple submucosal lymphomatous polyposis occurring in the rectum.  Our patient is a 39-year-old morbidly obese Hispanic female who presented to the gastroenterology clinic complaining of intermittent hematochezia for the past six months. Colonoscopy showed diffuse nodularity in the sigmoid colon and rectal mucosa, extending 20 cm from the rectal verge. Rectal biopsies revealed moderate active chronic inflammation predominantly of lymphoplasmacytic cells with areas of lymphoid hyperplasia and focal surface ulceration. Immunohistochemistry stains revealed reactive lymphoid hyperplasia (RLH).  The NLH is a risk factor for extraintestinal and intestinal lymphomas. When encountering lymphoid hyperplasias, the possibility of malignancy must always be considered. It is crucial to monitor patients with NLH via capsule endoscopies, small bowel series, and colonoscopy for surveillance of new lesions in light of the potential for malignancy.