Table 1 Histopathological classification of OSF
Very early stage (Grade I): | Early stage (Grade II): | Moderately advanced stage (Grade III): | Advanced stage (Grade IV): |
|---|---|---|---|
❖ A finely fibrillar collagen, dispersed with marked edema. ❖ The fibroblastic response is strong. ❖ The blood vessels are sometimes normal, but more often they are dilated and congested. ❖ Inflammatory cells, mainly polymorphonuclear leukocytes with an occasional eosinophil are present. | ❖ The juxta-epithelial area shows early hyalinization. ❖ Plump young fibroblasts are present in moderate numbers. ❖ The blood vessels are dilated and congested. ❖ The inflammatory cells are mostly mononuclear lymphocytes, eosinophils and an occasional plasma cell. | ❖ The collagen is moderately hyalinized. ❖ The fibroblastic response is less marked, the cells present being mostly adult fibrocytes. ❖ Blood vessels are normal or constricted. ❖ The inflammatory exudates consist of lymphocytes and plasma cells, although an occasional eosinophil is seen. | ❖ The collagen is completely hyalinized. ❖ The hyalinized areas are devoid of fibroblasts. ❖ Blood vessels are completely obliterated or narrowed. ❖ The inflammatory cells are lymphocytes and plasma cells. |