Intrahepatic Reactive Lymphoid Hyperplasia: A Case Report and Review of the Literature

Reactive Lymphoid Hyperplasia of the Liver Incidentally Found in a 55-Year-Old Woman with a History of Ulcerative Colitis

Reactive lymphoid hyperplasia (RLH) is a benign disease, rarely occurring in the liver. Reactive immune phenomenon has been reported in association with its occurrence, but the true pathogenesis is unknown. No case was reported in association with inflammatory bowel disease. We report a case of RLH of the liver in a patient with ulcerative colitis (UC). A 55-year-old woman with UC went to the outpatient clinic with abdominal pain, and antibiotics were prescribed with diagnosis of acute appendicitis. Imaging study detected a mass in the liver but ruled out appendicitis. She was referred to our hospital for further examination after pain improving. A 12 mm hypoechoic mass was detected in the liver on ultrasonography. There were no typical malignant findings on computed tomography and magnetic resonance imaging. Regular image follow-up was recommended, but the patient strongly requested surgery because of family history of malignant disease. Laparoscopic partial hepatectomy was performed. Histopathological findings revealed a conglomerate hyperplasia of lymphoid follicles with germinal centers. Infiltrating lymphocytes were non-neoplastic. Final diagnosis was RLH of the liver. UC is chronic inflammatory bowel disease and may be related to RLH, but there is no clear explanation at this point. This is the first known reported case of RLH of the liver in a patient with UC. But the relationship between the RLH and UC remains uncertain. Further investigation and case accumulation are necessary.

A case of hepatic reactive lymphoid hyperplasia: the review of 23 cases from the literatures

A 70-year-old woman was referred to our hospital because of slight elevation of soluble interleukin-2 receptor (sIL-2R) and accumulation of 18F-fluorodeoxyglucose (FDG) in S8 of the liver on positron emission tomography. The mass was strongly suspected to be malignant because of contrast enhancement and enlargement in size of the mass, and suspicion of portal vein invasion. Hepatic S8 subsegmentectomy was performed for diagnostic and therapeutic purposes. Hematoxylin and eosin staining of the resected specimen showed small lymphocytes with no atypia and no formation of lymphoid follicles. Immunostaining showed CD3-positive cells in the interfollicular region and CD20-positive cells in the lymphoid follicles. Both CD10 and BCL-2 were negative in the follicular germinal center. CD138-positive plasma cells were observed and there was no light chain restriction. Based on polyclonal growth pattern of lymphocytes in the lymphoid follicles and interfollicular region, she was diagnosed with hepatic reactive lymphoid hyperplasia (RLH).Review of the English literature of hepatic RLH which referred to imaging findings yielded 23 cases, including this case. As a result, we suggest that liver biopsy should be performed for definitive diagnosis, when hepatic RLH is suspected by imaging findings and backgrounds.

A case of reactive lymphoid hyperplasia of the liver in a patient with autoimmune hepatitis

Background

Reactive lymphoid hyperplasia (RLH) of the liver is a benign disorder. It is usually observed in the skin, orbit, thyroid, lung, breast, or gastrointestinal tract, but rarely in the liver. Since the first report of RLH of the liver in 1981, only 75 cases have been described in the past literature. Herein, we report a case of RLH of the liver in a patient with autoimmune hepatitis (AIH), which was misdiagnosed as hepatocellular carcinoma (HCC) preoperatively and resected laparoscopically.

Case presentation

A 43-year-old Japanese woman with autoimmune hepatitis was followed up for 5 years. During her medical checkup, a hypoechoic nodule in segment 6 of the liver was detected. The nodule had been gradually increasing in size for 4 years. Abdominal ultrasound (US) revealed a round, hypoechoic nodule, 12 mm in diameter. Contrast-enhanced computed tomography (CT) demonstrated that the nodule was slightly enhanced in the arterial dominant phase, followed by perinodular enhancement in the portal and late phases. A magnetic resonance imaging (MRI) scan showed low signal intensity on the T1-weighted image (T1WI) and slightly high signal intensity on the T2-weighted image (T2WI). The findings of the Gd-EOB-DTPA-enhanced MRI were similar to those of contrast-enhanced CT. Tumor markers were all within the normal range. The preoperative diagnosis was HCC and a laparoscopic right posterior sectionectomy was performed. Pathological examination revealed that the nodular lesion was infiltrated by small lymphocytes and plasma cells, and germinal centers were present. Immunohistochemistry was positive for B cell and T cell markers, indicating polyclonality. The final diagnosis was RLH of the liver.

Conclusions

The pathogenesis of RLH of the liver remains unknown, and a definitive diagnosis based on imaging findings is extremely difficult. If a small, solitary nodule is found in female patients with AIH, the possibility of RLH of the liver should be considered.