Clinical and histological patterns of dermatofibroma without gross skin surface change: A comparative study with conventional dermatofibroma

Fast-Growing Frontal Subcutaneous Nodule in a Young Woman

A woman in her 20s presented with a firm, mobile, painful, fast-growing subcutaneous nodule in the glabella. What is your diagnosis?

Challenging Patterns of Atypical Dermatofibromas and Promising Diagnostic Tools for Differential Diagnosis of Malignant Lesions

Dermatofibroma (DF) or fibrous histiocytoma is one of the most frequent benign cutaneous soft-tissue lesions, characterized by a post-inflammatory tissue reaction associated with fibrosis of the dermis. Clinically DFs have a polymorphous clinical aspect from the solitary, firm, single nodules to multiple papules with a relatively smooth surface. However, multiple atypical clinicopathological variants of DFs have been reported and, therefore, clinical recognition may become challenging, leading to a more burdensome identification and sometimes to misdiagnosis. Dermoscopy is considered an important tool in DFs diagnosis, as it improves diagnostic accuracy for clinically amelanotic nodules. Although typical dermoscopic patterns are most frequently seen in clinical practice, there have also been some atypical variants described, mimicking some underlying recurrent and sometimes harmful skin afflictions. Usually, no treatment is required, although an appropriate work-up may be necessary in specific cases, such as in the presence of atypical variants or a history of recent changes. This narrative review's aim is to summarize current evidence regarding clinical presentation, positive and differential diagnosis of atypical dermatofibromas and also to raise awareness about the importance of specific characteristics of atypical variants to better differentiate them from malignant conditions.

Hyperpigmented Nodular Dermatofibroma: Two Cases Report and Brief Literature Review

BACKGROUND: Dermatofibroma (DF) is a common benign skin tumor (Benign Fibrous Histiocytoma) that mostly affects the extremities with a tendency to occur more often in older females than males. It usually presents as a slow growing small brown dome shape papule on the extremities. DF has a chronic nature and can sometimes regresses spontaneously. Dermoscopy is essential in the evaluation of DF to help differentiate it with other skin tumors. The gold standard evaluation for diagnosis of DF is biopsy with histopathologic examination. Removal of DF is often due to cosmetic factors, with surgical excision being the preferred method for removal. DF has an excellent prognosis. CASE REPORT: We present two case reports of women with hyperpigmented nodules on the lower extremity. Dimple sign was positive. From dermoscopic study showed a pigment network and central white patch pattern. On histologic examination revealed proliferation of fibroblast such as spindle cells as a storiform pattern and hyperplastic epidermis with hyperpigmentation of the basal layer. Based on clinical features, dermoscopy and histopathological evaluation, the diagnosis of DF was established. Both patients were perform surgically excision and have a good result. CONCLUSION: Dermatofibroma is benign fibrous histiocytoma that represents one of the most common skin tumours. Nodular hyperpigmented dermatofibroma is a clinical variant of Dermatofibroma which can be treated with surgical excision with good prognosis.