Sir,

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor of mesenchymal origin with low metastatic potential yet high propensity for local recurrence [1]. Incident rates range from 0.8 to 4.5 cases per million per year. The main etiological factor in the development of DFSP is the presentation of several previous traumas, including surgical and traumatic scars, burns, and insect bites [2,3]. It usually occurs in young or middle-aged patients yet may present in all age groups [4]. DFS is a tumor affecting primarily the trunk, as it may develop in the extremities, including the head and neck. DFSP is a slow-growing tumor that is asymptomatic for several years, which often delays its diagnosis [5]. Its positive diagnosis is based on histological and immunohistochemical confirmations, and its optimal treatment is based on extensive resection. Because it is a radiosensitive tumor, radiation therapy should be considered when the tumor cannot be completely excised. Chemotherapy is reserved for adult patients with metastatic, unresectable, or recurrent disease [4,5].

Herein, we report a case of DFSP mimicking a proliferating trichilemmal cyst.

The patient was seventy-years-old and was admitted for the management of a scalp tumor that had been evolving for three years. On dermatological examination, the scalp was found to contain a well-defined, roughly rounded, erythematous mass measuring 6 cm with a soft consistency and a smooth surface topped by a hemorrhagic crust, located on the vertex (Fig. 1a). Dermoscopy showed a purplish, erythematous background, whitish areas without structures, a rainbow aspect, and polymorphic vascularized structures made primarily of tortuous vessels (Fig. 1b). Ultrasound of the lymph nodes was normal, and a brain scan was performed yet did not reveal bone involvement. The patient underwent a diagnostic biopsy confirming the diagnosis of DFSP with positive CD34+ immunostaining. The patient will be a candidate for large surgery with close follow-up.

Figure 1: (a) Large dermatofibrosarcoma protuberans of the scalp.(b) Dermoscopic features: purplish, erythematous background (black arrow), whitish areas without structures (green asterisk), a rainbow aspect (white arrows), and tortuous vessels (yellow arrows).

REFERENCES

1.Al-Khattab M, Kennedy S, Jones D. Dermatofibrosarcoma protuberans of the scalp. Clin Case Rep. 2022;10:05703.

2.Hongo T, Nakamura T, Miyake A, Kato I, Tateishi K, Yamanaka S, Yamamoto T. Evaluation of tumor cell infiltration to the skull in dermatofibrosarcoma protuberans of the scalp:Case report and literature review. NMC Case Rep J. 2021;8:287-93.

3.Frikha F, Mseddi M, Bahloul E, Chaabouni R, Masmoudi A, Boudaya S, et al. [Dermatofibrosarcoma protuberans (report of 49 cases)]. Our Dermatol Online. 2020;11:25-31.

4.Bambara AH, Ouedraogo AN, Ouedraogo Nde NA, Ili VB, Sanou J, Chtioui AT, Konsem T. Dermatofibrosarcoma Darier Ferrand under orbital:A rare location. Our Dermatol Online. 2017;7(Suppl. 1):372-6.

5.Kanesen D, Zakaria Z, Ch’ng ES, Nandrajog P, Kandasamy R. Dermatofibrosarcoma protuberans of the scalp:Therapeutic challenges. ANZ J Surg. 2019;89:261-4.