Reactive Lymphoid Hyperplasia with a Lipomatous Component Associated with Fecal Compaction in an Appendiceal Orifice

Abstract

A 69-year-old man underwent endoscopic mucosal resection of a solitary polyp located in the cecum. After the procedure, a fecal mass and appendiceal orifice appeared under the cut surface. A diagnosis of reactive lymphoid hyperplasia was made based on the results of an immunostaining analysis, which revealed a segregated population of T cells and B cells in multiple lymphoid follicles. The aggregation of adipocytes forming a lipomatous area and granulation tissue was also observed. We speculate that the compaction of the fecal mass in the appendix triggered mucosal inflammation, resulting in the formation of the polyp, which concealed both the feces and appendiceal orifice.

Impacted golf tee shaped appendiceal fecalith causing appendiceal non-visualization and mimicking cecal mass: A case report

“…Appendicitis is the most common acute abdominal emergency in the United States, with a lifetime risk of developing appendicitis estimated to be 7% [5]. Fecaliths are considered to play a key role in the pathogenesis of appendicitis [1,3]. Fecaliths are hardened, compact, stony chunks of feces found in the intestines [3].…”

“…Fecaliths are considered to play a key role in the pathogenesis of appendicitis [1,3]. Fecaliths are hardened, compact, stony chunks of feces found in the intestines [3]. In the appendix, fecaliths cause obstruction of the appendiceal lumen, leading to stasis of its contents, causing bacterial overgrowth and inflammation, ultimately culminating in appendicitis [3].…”

“…It is thought to result from the luminal obstruction of the appendix caused either by a fecalith or lymphoid hyperplasia, which leads to accumulation of mucin distal to the obstruction, bacterial overgrowth, and inflammation. This eventually causes increased intraluminal pressure, ischemia, and perforation of the appendix [2,3].…”

“…Fecaliths play a vital role in the pathogenesis of appendicitis [3] and can be identified through computed tomography (CT) [2]. Thus, diagnosis of acute appendicitis is based on clinical signs and symptoms and radiographic evidence of fecalith and/or radiographic features of acute appendicitis [1,4].…”

Reactive lymphoid hyperplasia of the liver

“…Reactive lymphoid hyperplasia (RLH), also known as pseudolymphoma or nodular lymphoid lesion of the liver was first reported in 1981 by Snover et al [1] RLH was a benign nonspecific lesion characterized by a marked proliferation of polyclonal lymphocytes forming follicles with an active germinal center. [2] RLH had been reported in various organs, including the skin, [3] lung, [4] eye orbit, [5] intestine, [6] and thyroid, [7] but it is an uncommon benign lesion in the liver. It was usually difficult to differentiate from hepatocellular carcinoma (HCC), peripheral-type cholangiocellular carcinoma (CCC), combined HCC-CCC, and liver metastases.…”