Pleomorphic fibroma D 48.-

Kamino H et al. 1989

Rare, slow-growing, 0.4 to 1.6 cm large, nodular connective tissue, soft, symptomless tumor, which can clinically resemble a fibroma molle, but can also grow subungually like a plate.

Adults aged between 33 and 67 years (average: 52 years)

Preferred locations are the extremities, trunk, face (Kamino H et al. 1989). In one case a subungual localization was described (Halteh P et al. 2016),

Below a normally structured epidermis, there is a convolute of spindle-shaped, conspicuously pleomorphic, vimentin-, actin- and CD34 positive fibroblasts/myofibroblasts. Negative immunoreactivity for CD31, S-100, and CD68 (Mahmood MN et al. 2003). Injected are multinucleated giant cells (Tashakori M et al. 2018). In some places an adipocyte component may also be present.

Dermatofibroma, atypical lipomatous tumour; dermatofibroma with monster cells (CD34 negativity - Rudolph P et al. 1999).

Due to the less typical clinical picture, the diagnosis is made exclusively histologically.

1. de Feraudy S, Fletcher CD (2012) Fibroblastic connective tissue nevus: a rare cutaneous lesion analyzed in a series of 25 cases. On the J Surg Path 36:1509-155.
2. Halteh P et al (2016) Subungual pleomorphic fibroma: a case report and review of the literature. Dermatol Online J 22: 11.
3. Kamino H et al (1989) Pleomorphic fibroma of the skin: a benign neoplasm with cytologic atypia. A clinicopathologic study of eight cases. On J Surg Pathol 13:107-113.
4. Mahmood MN et al (2003) Solitary sclerotic fibroma of skin: a possible link with pleomorphic fibroma with immunophenotypic expression for O13 (CD99) and CD34. J Cutan Pathol 30):631-636.
5. Rudolph P et al (1999) Differential expression of CD34 and Ki-M1p in pleomorphic fibroma and dermatofibroma with monster cells. At J Dermatopathol 21:414-419.
6. Tashakori M et al (2018) Pleomorphic fibroma of the skin with MDM2 immunoreactivity: A potential diagnostic pitfall. J Cutan Pathol 45:59-62.