Linear dermatomyofibroma over the nape of neck: a report of an unusual case and literature review

Abstract

Dermatomyofibroma is a rare cutaneous mesenchymal tumor of benign fibroblastic and myofibroblastic derivations. It predominantly affects young women, and it usually presents as a reddish-brown plaque or nodule, which is commonly located over the upper trunk. We report the case of a 41-year-old female patient who presented with progressive linear dermatomyofibroma over the nape of her neck. This case report expands the knowledge about the clinical and histopathological features of this rare, benign and cutaneous tumor.

Keywords: cutaneous; dermatomyofibroma; immunohistochemistry; mesenchymal tumor; myofibroblasts.

Figure 1

Clinical presentation of dermatomyofibroma showing an ill-defined and linear reddish-brown indurated dermal plaque measuring approximately 7 × 3 cm over the nape of the neck.

Figure 2

(A) Low-power microscopic view of dermatomyofibroma showing the infiltrating fascicles of bland-looking spindle cells. Hematoxylin-eosin stain ×100. (B) High-power microscopic view of dermatomyofibroma showing the spindle- and oval-shaped nuclei of the tumor cells, which are mixed with small blood vessels and lipocytes. Note the absence of necrosis, pleomorphism and mitoses. Hematoxylin-eosin stain ×400

Figure 3

(A) IHC stain for h-caldesmon is strongly positive. This finding is in favor of dermatomyofibroma. The tumor was, however, negative for CD34, factor 13A and S100 protein. IHC stain ×200. (B) IHC stain for C-34 is negative. Note the presence of positive internal control in some blood vessels. IHC stain ×400.