Hemosiderotic dermatofibroma mimicking melanoma in a 12‐year‐old boy: a case report

Abstract

Key Clinical MessageWe report a case of hemosiderotic dermatofibroma presenting as a brown‐black‐colored nodule with peripheral extensions, which mimics melanoma. Histopathology showed completely benign features with no atypia or mitosis. Nodular extensions of childhood dermatofibromas may be related to the growth of the child not necessarily pointing to a malignant process.

Hemosiderotic dermatofibroma mimicking melanoma: A case report and review of the literature

“…Majority of these cases raise concern for melanoma following initial dermatoscopic examination and excision was performed for a definite diagnosis. 11,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] The area rich in poorly formed vessel-like structures can make the lesion look like a vascular tumor such as Kaposi's sarcoma both microscopically and clinically. 28 Given the patient having no clinical history of immunosuppressive diseases/conditions, the chance of Kaposi's sarcoma is likely to be very low.…”

“…Rapid expansion of the lesion caused by dermal hemorrhage can also raise the concern for the progression of a malignant disease. 21 Other fibrohistiocytic lesions that can clinically mimic melanoma or melanocytic lesions include atypical 29 ECH presents as nodular to sheet-like well-circumscribed proliferation in papillary dermis which is clinical and histologic mimic of intradermal Spitz nevus. 30 It is associated with rearrangement and overexpression of anaplastic lymphoma receptor tyrosine kinase (ALK).…”

“…When in doubt, immunohistochemical staining for HHV‐8 and vascular markers including CD31 and ERG can pinch the diagnosis. Some studies suggest that HDF is a precursor of aneurysmal DF (ADF) 3,20,21 which is characterized by cavernous‐like blood‐filled large space in the dermis. The hypothesis favors a slow process of blood leaking and building up, thus forming the final large blood‐filled space.…”

Hemosiderotic Dermatofibroma: A Rare and Atypical Variant Capable of Clinically Resembling Melanoma

“…DFs are relatively common skin lesions, approximately 3% of all skin lesions, appearing most often in the lower extremities of young adult females [1,6]. Atypical variants of DF, such as HDF (once progressed to aneurysmal DF [ADF]), are more likely to have high proliferative activity and recurring metastasis with metastasis noted as early as three months after first diagnosis [7,8]. In contrast, the median time-to-metastasis for localized melanoma is 28 months [9].…”

SnapshotDx Quiz: July 2020

“…Malignant melanoma: Malignant melanoma is a malignancy of pigment-producing melanocytes that can arise on the skin and mucous membranes, around the nail apparatus, and in the eye. Clinically, the hemosiderotic variant of DF may mimic melanoma, as hemosiderotic DF may present as a dark brown to black papulonodule (Acar et al, 2018). The desmoplastic variant of melanoma may be considered in the histopathologic differential diagnosis of DF.…”