What is the primary histopathological finding in active otosclerosis?

Explanation

## Histopathology of Otosclerosis **Key Point:** Otosclerosis is characterized by abnormal bone remodeling with simultaneous osteoclastic resorption and osteoblastic new bone formation, creating a dynamic lesion. ### Active Phase Histology The active (otospongiotic) phase shows: 1. **Osteoclastic activity:** Resorption of normal otic capsule bone 2. **Osteoblastic activity:** Deposition of abnormal, highly vascular bone 3. **Increased vascularity:** Rich blood supply within the lesion 4. **Disorganized bone architecture:** Loss of normal lamellar structure ### Disease Progression | Phase | Histology | Clinical Significance | |-------|-----------|----------------------| | **Active (Otospongiotic)** | Osteoclasts + osteoblasts, vascular, disorganized bone | Progressive hearing loss, may progress rapidly | | **Inactive (Otosclerotic)** | Dense lamellar bone, sclerosis, hypovascular | Stable hearing loss, no further progression | **High-Yield:** The active phase is characterized by **bone remodeling** (both resorption and formation), NOT simple sclerosis. This is why fluoride therapy has been investigated—to suppress osteoclastic activity. ### Clinical Correlation **Clinical Pearl:** Patients with active otosclerosis may show progressive hearing loss over months to years. Once the lesion becomes sclerotic (inactive), hearing loss plateaus. Imaging (CT) may show lucent lesions in the active phase and dense lesions in the inactive phase. **Mnemonic:** **ACTIVE otosclerosis = Abnormal bone remodeling (Osteoclasts + Osteoblasts) + Vascularity**