Solitary skin-colored nodule on a child’s face

Abstract

Sir, A healthy, six-year-old boy presented with a slowly grown dome-shaped nodule on the mandibular angle region present for two years. The patient’s past medical and family history were unremarkable. A physical examination revealed a solitary, 1.3 × 1 cm, firm, painless, flesh-colored tumor (Fig. 1). Dermoscopy showed branching, serpentine vessels on a pink background (Fig. 2a). These features disappeared when slight pressure was exerted on the dermoscope and the tumor exhibited a central, white, structureless area (Fig. 2b). An excisional biopsy was performed. A microscopic examination showed a well-circumscribed, paucicellular dermal tumor composed of eosinophilic collagen bundles separated by clefts and forming a storiform pattern. Scattered fibroblasts were found among the collagen bundles. The overlying epidermis was slightly flattened (Fig. 3). The diagnosis of solitary sclerotic fibroma was established. Sclerotic fibroma (SF), also known as storiform collagenoma, is a rare benign skin tumor. It usually manifests itself as an asymptomatic, slowly growing, white-to-skin-colored papule or nodule [1]. It was first described in patients with Cowden’s disease, yet may also occur sporadically [2]. There were no mucocutaneous features of Cowden’s disease (tricholemmomas, oral fibromas, acral keratoses, palmar pits, and gingival and palatal papules) in the patient and her family members. Dermatofibroma, the main differential diagnosis of SF, usually exhibits hyperplastic changes of the epidermis instead of atrophy, and the boundaries of the lesion are unclear [2]. Only two papers have been published describing the dermoscopic findings of SF, consisting of a white background with peripheral arborizing vessels [3]. A white background may be related to an increased dermal collagen density. It is also described in dermatofibroma, typically with a peripheral pigmentation network. Although dermoscopy may improve the clinical diagnosis of SF, histopathological analysis is required.