Proliferative Fasciitis : Differential

Comments:
Differential Diagnosis of Proliferative Fasciitis: The ganglion-like cells may be mistaken for rhabdomyoblasts leading to an erroneous diagnosis of embryonal rhabdomyosarcoma. The ganglion-like myofibroblasts of proliferative fasciitis have more basophilic cytoplasm (unlike eosinophilic appearance of rhabdomyoblasts) and lack cross striations.

Some cases are misdiagnosed as ganglioneuroblastoma. However, it lacks the fibrillary background of ganglioneuroma and ganglioneuroblastoma. Long-standing lesions of proliferative fasciitis have abundant hyalinized collagen surrounding ganglion-like cells and such foci may mimic malignant osteoid and the case misdiagnosed as osteosarcoma.

The image shows large ganglion-like myofibroblasts in a background of myxoid stroma from a case of proliferative fasciitis.