Rebound adenoid hyperplasia after chemotherapy in pediatric patients with head and neck lymphoma: MR imaging findings

Purpose: To assess MR imaging findings of rebound adenoid hyperplasia after chemotherapy in pediatric patients with head and neck lymphoma.

Materials and methods: Eight pediatric patients with head and neck lymphoma treated with chemotherapy alone or concurrent chemoradiotherapy were included. All patients underwent pre-therapeutic assessment and post-therapeutic follow-up by MR imaging. The maximum thickness of the adenoid was assessed on transverse T2-weighted images. Rebound adenoid hyperplasia was defined as more than half of the pre-therapeutic thickness after severe atrophy.

Results: The pre-therapeutic maximum thickness of the adenoid ranged from 10 to 18 mm (mean, 15 mm). In all patients, the thickness of the adenoid dramatically decreased (mean 1 mm) within 1 year after the cessation of chemotherapy. On follow-up MR imaging, rebound adenoid hyperplasia was observed in five patients (63 %). Re-atrophy following rebound adenoid hyperplasia was observed in two patients (25 %), and no re-atrophy was observed in three patients (37 %). Rebound adenoid hyperplasia was not observed in three patients (37 %) who were in their late teens, and who had been treated with concurrent chemoradiotherapy.

Conclusion: Rebound adenoid hyperplasia was often observed after chemotherapy in pediatric patients with lymphoma. MR imaging was useful for the assessment of rebound adenoid hyperplasia.