Langerhans cell histiocytosis presenting as a cecal mass in an adolescent: a rare surgical case report.

Introduction and importance: Langerhans cell histiocytosis (LCH) is a rare, idiopathic, multifocal disease that commonly occurs in the skin and skeletal system, although involvement of the gastrointestinal tract is exceptional. Only a limited number of cases have been reported in the literature, particularly at the intestinal level, often with incidental diagnosis after colonoscopic polypectomy, and presentation as a cecal mass is extremely uncommon. Case presentation: A 15-year-old boy presented with abdominal pain and a non-tender right iliac fossa mass. Hematological and biochemical tests were within normal limits. Initial imaging studies, including ultrasound and contrast-enhanced computed tomography, revealed a cecal mass associated with mesenteric lymphadenopathy, with radiological features suggestive of lymphoma. Because of intolerance to bowel preparation, colonoscopy could not be performed. In addition to a history of treated intermittent distension with vomiting, which raised concern for recurrent sub-acute intestinal obstruction, a laparoscopy-assisted surgical approach was therefore chosen. Intraoperatively, a cecal mass with multiple focal swellings of the mesocolon was identified. A right hemicolectomy with ileo-transverse anastomosis was performed according to oncological principles. Post-operative PET imaging showed no evidence of residual disease, and the patient was subsequently enrolled in a follow-up program. This case highlights the rarity of intestinal LCH and the importance of considering it in the differential diagnosis of abdominal masses in pediatric patients. Radiological imaging studies have shown neither residual disease nor recurrence during 9 months of regular follow-up. Clinical discussion: The World Health Organization classifies LCH within the hematopoietic and lymphoid tumors placing it on a spectrum between benign and malignant behavior depending on other factors, with unifocal or multifocal lesions and single- or multisystem involvement, which likely predict prognosis and guide post-surgical treatment. Conclusion: The rarity of intestinal LCH presenting as a cecal mass highlights the importance of considering it in the differential diagnosis of abdominal masses in pediatric patients.