Myospherulosis in Temporal Bone After Surgery Resembles Cholesteatoma on Imaging

Abstract

Myospherulosis, also known as spherulocytosis, is a for eign body-type granulomatous reaction to lipidcontaining material and blood. It is caused by the inter action of extravasated erythrocytes and exogenous or endogenous lipids, and can occur in any part of the body at any age (1). It may be seen in various clinical settings including fat necrosis, difficult differential diagnosis in malignancy (e.g., renal cell carcinoma), and after place ment of topical tetracycline in a petrolatum base into asurgical site. Our focus is with the last setting. In addition to being a well-known rhinological intervention, it has also been reported in the mastoid after ear surgery by Manni et al. among others (2).Classically, cholesteatoma surgery using a combined approach tympanoplasty (canal-wall preserving technique) is done in two surgical interventions with a 9-to 12-month interval between them. The first surgery stage is to eradicate cholesteatoma from the middle ear and the second stage is to do the final check for residual cholesteatoma and to perform an ossicular reconstruction to restore the conductive hearing loss, if present. This ''classic'' trend is now changing because of improved radiological techniques such as diffusion-weighted MRI (DWI) and, in particular, non-echo planar DWI. These types of imaging techniques allow for a single-stage surgery (removal of cholesteatoma and reconstruction of the ossicular chain) eliminating the need for a second-look operation. DWI MRI allows for detection of cholesteatoma starting from 2 mm 3 and larger.Here we point out a possible pitfall in the management of cholesteatoma with DWI MRI for surgeons who use ear packing in the outer ear canal containing ointment on a petrolatum base. We describe a case with a well-known medical history with cholesteatoma surgery that had radiological arguments for residual cholesteatoma on DWI MRI. Surgical intervention showed myospherulosis, most likely provoked by ointment packing for previous ear surgery. CASE PRESENTATIONA 52-year-old male patient was being seen for a follow-up appointment. In reviewing his medical history, it was found that he had a complicated cholesteatoma leading to meningoencephalitis that had been surgically treated 5 years before and included a second-look surgery with a successful ossicular chain reconstruction. In both surgical reports, ear packings containing antibiotic ointments were mentioned.The patient recently experienced some discomfort, and because of his complicated otological history, a DWI MRI was performed to verify that there was no clinical or otoscopic suspicion for cholesteatoma and hearing thresholds had not deteriorated. However, as shown in Figure 1, the scan indicates possible arguments for cholesteatoma. Yet another operation was performed based on this scan, but cholesteatoma was ruled out during the surgery. Instead, the demonstrated mastoid lesion was taken for biopsy and sent for histopathology which showed arguments for myospherulosis (Fig. 2). The patient recovered swiftly and without any c...