[Mucosa-associated lymphoid tissue lymphoma in children and adolescents: a clinicopathologic study of 5 cases].

Objective: To investigate the pathological features and clinical manifestations of mucosa-associated lymphoid tissue (MALT) lymphoma in children and adolescents. Methods: Five cases of MALT lymphoma in children were investigated by morphology and immunophenotyping along with clinical follow-up. Results: Five cases of MALT lymphoma occurred in the antrum, orbit, parotid gland and nasopharynx. All patients had no B symptoms and only one patient showed a local mass with ulcer. One case presented with cervical lymph node enlargement, and 4 cases showed no evidence of lymphadenopathy.All cases had pathological features similar to those of adult MALT lymphoma, with proliferation of monocytoid B cells orcentralcyte-like tumor cells, with plasma cell differentiation and lymphoid epithelial lesions.No specific immunophenotypic marker was found. Clonal Ig gene rearrangement was detected in two cases.One patient was treated with rituximab treatment, 1 patient was given anti-Helicobacter pylori therapy, and 2 patients had no additional treatment.The follow-up data showed that 4 patients survived without tumor recurrence. Conclusions: Similar to adult patients, MALT lymphoma in children and adolescents has similar pathological features with indolent clinical course and good prognosis. It is important to note that misdiagnosis and incorrect diagnosis mightoccur because of the young age of the patients.