Foreign Body Granuloma Originating from the Lateral Process of Malleus: A Case Series of 19 Children

Abstract

Objective A special presentation of foreign body granuloma originating from the lateral process of the malleus (FBGLP) was noted in the absence of a history of foreign body entry into the external auditory canal (EAC). This study reported the clinical features, pathology, and prognosis of patients with FBGLP. Design Retrospective study. Setting Shandong Provincial ENT Hospital. Patients Nineteen pediatric patients (age, 1-10 yr) with FBGLP. Interventions Clinical data were collected from January 2018 to January 2022. Main Outcome Measures Clinicopathologic characteristics of the patients were analyzed. Results All patients had an acute course, and were within 3 months of ineffective medical treatment. The most common symptoms were suppurative (57.9%) and hemorrhagic (42.1%) otorrhea. FBGLP imaging examinations demonstrated a soft mass blocking the EAC without bone destruction and occasionally concomitant effusion in the middle ear. The most common pathologic findings were foreign body granuloma (94.7%,18/19), granulation tissue (73.7%, 14/19), keratotic precipitate (73.7%, 14/19), calcium deposition (63.2%, 12/19), hair shafts (47.4%, 9/19), cholesterol crystals (5, 26.3%), and hemosiderin (15.8%, 3/19). Foreign body granuloma and granulation tissue showed higher expression levels of CD68 and cleaved caspase-3 than did the normal tympanic mucosa, whereas Ki-67 levels were similarly low in all tissues. The patients were followed up for 3 months to 4 years without recurrence. Conclusion FBGLP is caused by endogenous foreign particles in the ear. We recommend the trans-external auditory meatus approach for FBGLP surgical excision, as this shows promising outcomes.