A Case Report of Mesenteric Cystic Lymphangioma with Multiple Abdominal Organs Granulomas

Abstract

Introduction. Mesenteric cystic lymphangioma is a rare, slow-growing intra-abdominal mass, primarily affecting the small-bowel mesentery, with occasional involvement of the omentum, mesocolon, and retroperitoneum. Arising from lymphatic malformations of unclear etiology, it predominantly occurs in males (5:2 ratio). Since this condition coexists with immune dysfunction in some patients, an underlying immunodeficiency should be considered. Combined immunodeficiency profoundly impairs vaccine efficacy, sometimes rendering immunization ineffective or triggering severe, life-threatening reactions. Case report. A 4-year-old boy was referred to pediatric urologists due to an enlarged urinary bladder. Abdominal ultrasound revealed a normal bladder but identified a 16x11x12 cm cystic mass in the small-bowel mesentery. Further diagnostic tests were performed, and the cyst was surgically excised. Histopathological examination confirmed the diagnosis of mesenteric cystic lymphangioma. Intraoperatively, multiple granulomatous lesions (about 10 mm dia­meter) were indentified across abdominal organs, prompting the collection of biopsies. Extensive diagnostic testing, including TBC, HCV, HBC, CMV, EBV, and HIV, yielded negative results. Subsequently, focal lesions emerged in the left testicle where biopsu analysis detected rubella virus RNA. Based on the patient’s clinical history, disease progression, and laboratory findings, a diagnosis of combined immunodeficiency was established, potentially triggered by a rubella vaccine or a newly acquired condition, for which no specific treatment is available. Discussion. Mesenteric cystic lymphangioma is a rare benign anomaly, occurring in approximately 1 in 250,000 cases, predominantly in asymptomatic pediatric patients. Ultrasonography typically identifies a painless, soft, mobile mass in 58% of cases. The coexistence of abdominal granulomas is unusual and suggests underlying immune dysfunction. In individuals with primary immunodeficiencies, rubella vaccine strains have been implicated in chronic granulomatous disease, indicating that immune defects may facilitate viral persistence and dysregulated immune responses. The detection of rubella virus RNA in testicular lesions further implicates the virus in granuloma formation. This highlights the importance of screening for immunodeficiency in pediatric patients with atypical granulomatous inflammation, particularly when vaccine-strain viruses are involved. Early diagnosis is essential for optimizing management and preventing complications. Conclusions. Mesenteric cystic lymphangiomas are intra-abdominal tumors primarily affecting young children, with complete excision being the most effective treatment to prevent recurrence. This case emphasizes evaluating immunodeficiencies in patients with atypical abdominal granulomas. Recent studies have detected rubella virus antigen and RNA in granulomas across multiple organs in children with primary immunodeficiencies, typically emerging near the MMR vaccination site within 2 to 152 weeks (average 48 weeks).