Myospherulosis of the middle ear: A case report and systematic review of literature

Introduction: Myospherulosis is a rare foreign body reaction that typically results from a physical emulsion phenomenon between lipid-containing material and erythrocytes. It most frequently manifests in the paranasal sinuses and subcutaneous tissues. We report a new case of middle ear myospherulosis following application of topical bacitracin during myringoplasty and include a systematic review of the literature. Case description: A 10-year-old female was referred for right unilateral conductive hearing loss (CHL). Surgical history was significant for ipsilateral tube removal with myringoplasty performed three years prior to referral. Postoperatively, the patient experienced progressive CHL in the setting of an intact tympanic membrane. Computed tomography revealed nonspecific middle ear opacities and inconspicuity of the incus. Middle ear exploration revealed complete erosion of the incus long process with thickened adjacent tissue and apparent residual bacitracin ointment. Tissue debrided from the middle ear was sent for histopathology, which was consistent with myospherulosis. Systematic review: EBSCO, PubMed, and Cochrane databases were searched from inception to March 2024. Reports of myospherulosis involving the ear were included. We found seven cases of middle ear myospherulosis from 1977 to 2013. 42.9 % of cases presented with CHL and 71.4 % with persistent otorrhea. Mean time to diagnosis was 36.8 months (SD +/- 22.28). Bacitracin, Terra-Cortril, and nonspecific ointment/petroleum-based antibiotics were used in all cases; 28.6 %, 42.9 %, and 28.6 % of the cases, respectively. Conclusions: Persistent otorrhea and CHL following procedures that use oil or petroleum-based ointments or antibiotics should raise suspicion for middle ear myospherulosis. Surgeons should use caution or consider the role of alternative ointments.