Histopathology of fluoroscopy‐induced radiation ulcer: a case series study in comparison with morphea

Summary Background and objectives Histopathologic diagnosis of fluoroscopy‐induced radiation ulcer (FIRU) can be challenging if the past history of radiation exposure is unknown. Morphea is the most important differential diagnosis. This study was intended to identify clinical and pathologic features that can be used to distinguish FIRU from morphea. Patients and methods We performed a retrospective study on 25 specimens from 15 patients with FIRU and 21 specimens from 21 patients with morphea. Clinical findings and pathological features were analyzed. Results Thirteen of 15 patients (86.7 %) with FIRU underwent angioplasty for coronary artery disease, and eleven patients had lesions in the right subscapular area. Compared with morphea, FIRU patients were more likely to display non‐inflammatory infiltrates (28 %), bizarre fibroblasts (100 %), sclerosis (48 %), telangiectasia (96 %), vascular damage (64 %), and loss of skin appendages (100 %). In morphea, bizarre fibroblasts were rare (14 %), while telangiectasia (62 %) and loss of skin appendages (62 %) were variable. Loss of CD34+ cells and compression of elastic fibers could not be used to distinguish between FIRU and morphea. Conclusions Skin lesion in the right subscapular area with presence of bizarre fibroblasts, sclerosis, telangiectasia, and loss of cutaneous appendages as seen with histology are highly characteristic of the radiation damage associated with fluoroscopic angiography.