Dermatofibroma Over The Scar – A Rare Entity

Abstract

Dermatofibroma is a common benign dermal tumour of unknown aetiology. With varied clinical presentation mimicking keloid, desmoid tumour and leiomyoma, the diagnosis of Dermatofibroma sometimes become problematic from the clinician side. Here, we report a case of Dermatofibroma in a not so common site which was clinically diagnosed to be a keloid. But later, the lesion turned out to be a dermatofibroma on histopathological examination. In our patient, the lesion was a single smooth circumscribed nodule over the left side of the abdomen. The lesion had a linear scar on either side and on palpation; it was firm in consistency. It was initially diagnosed to be a keloid which even after multiple intra-lesional steroid injections, failed to show any results. This prompted us to search for an alternate diagnosis; hence lesion was excised and analyzed. The Histopathological examination revealed a circumscribed lesion in the dermis, composed of benign spindle-shaped cells arranged in a storiform pattern. These findings, as mentioned above, were consistent with a diagnosis of Dermatofibroma, which is a slow-growing tumour commonly seen in the extremities. The keloid like a presentation of Dermatofibroma, is one another example of how a similar morphological presentation may have two distinct diagnoses resulting in a delay in providing appropriate treatment.