迷路内手術標本から得られた骨化性迷路炎の病理学的検討

Histopathology of Labyrinthitis Ossificans From an Intralabyrinthine Surgical Specimen.

抄録

目的:

骨化性迷路炎（Labyrinthitis Ossificans：LO）の組織学的特徴は、これまでほとんど死後標本に限られていた。本報告では、人工内耳埋め込みと同時に迷路摘出術を受けた患者の手術標本から得られたLOの組織学的特徴について述べる。

OBJECTIVE: Histologic characterization of labyrinthitis ossificans (LO) has mostly been limited to postmortem samples. In this report, we describe the histology of LO from a surgical specimen obtained from a patient undergoing labyrinthectomy with simultaneous cochlear implantation.

症例:

急性めまい、左側難聴、耳鳴り、耳閉感を訴えて救急外来を受診した38歳女性。

PATIENT: A 38-year-old woman initially presenting to the emergency room with acute vertigo, left-sided hearing loss, tinnitus, and aural fullness.

介入方法:

迷路切除術と人工内耳埋め込み術の前に，この患者に対して造影MRIとコンピュータ断層撮影（CT）が実施された．聴力検査は手術前と手術後に実施した。組織学的分析は、手術中に左側半規管（SCC）から得られた標本に対して行われた。

INTERVENTIONS: Contrast-enhanced magnetic resonance imaging (MRI) and computerized tomography (CT) were performed for the patient before labyrinthectomy and cochlear implantation. Audiometric testing was performed before and after surgical intervention. Histologic analysis was performed on a specimen obtained from the left lateral semicircular canal (SCC) during surgery.

主要評価項目:

MAIN OUTCOME MEASURES: Preoperative CT and MRI findings, preoperative and postoperative hearing thresholds via air conduction and bone conduction, hematoxylin and eosin (H&E) stain of the surgical sample, and CD45 immunostain of the surgical sample.

結果:

RESULTS: Preoperative CT and MRI confirmed the diagnosis of isolated LO of the left lateral SCC. Audiometric testing revealed significant improvement in hearing after labyrinthectomy and cochlear implantation. H&E stain demonstrated fibrosis and ossification in the left lateral SCC, and CD45 immunostain was negative.

結論:

手術用サンプルに基づく LO の病理組織学的解析は、他のヒト組織で見られる異所性骨化（HO）と同等である。LOとHOの類似性を考えると、HOの予防に有効な薬剤はLOの予防にも有用である可能性がある。

CONCLUSIONS: Histopathology of LO based on a surgical sample is comparable to heterotopic ossification (HO) seen in other human tissue. Given the similarities between LO and HO, agents effective in preventing HO may have utility in preventing LO.