Dermatofibrosarcoma Protuberans of the Scalp in a 15-year-old Boy: A Rare Pediatric Surgical Challenge

ABSTRACT

Dermatofibrosarcoma protuberans (DFSP), a seldom-seen, intermediate-grade sarcoma of the skin, carries a substantial risk of local recurrence when surgical removal is insufficient. We document a case of a 15-year-old boy who presented with a painless scalp swelling, initially diagnosed elsewhere, as benign. Wide local excision confirmed fibromatous DFSP. The significance of early detection and appropriate surgical margins is underscored by this case.

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a rare, intermediate-grade skin cancer that grows slowly but acts aggressively locally.[1] Less than 0.1% of all malignancies and roughly 1% of soft tissue sarcomas are attributable to this.[2] Pediatric cases are not common, with scalp involvement being even rarer. The lesion’s resemblance to benign conditions such as cysts, lipomas, or fibrous proliferations frequently leads to delayed diagnosis.[3] Incomplete removal leads to a high chance of recurrence.[1,3] Complete surgical excision with clear margins remains the mainstay of treatment.[1]

CASE REPORT

A 15-year-old boy presented with a gradually enlarging painless swelling over the scalp for several months. The lesion had initially been considered benign elsewhere and was kept under observation. There was no history of trauma or neurological symptoms.

On clinical examination, a firm, nontender nodular exophytic swelling was noted over the scalp. The lesion was mobile over the underlying structures. There was a lymph node in the neck (level II) on the right side. Fine needle aspiration cytology was done which was reported to be a reactive lymph node. Axial noncontrast computed tomography (CT) scan of the head showing a well-defined extracranial soft-tissue mass arising from the scalp, abutting the outer table of the calvarium [Figure 1]. The underlying skull was intact with no evidence of bony erosion or intracranial extension.

Figure 1.

Clinical photograph showing a swelling over the scalp with focal ulceration of the overlying skin. Axial computed tomography imaging of head shows a well-defined soft-tissue mass arising from the scalp without calvarial involvement

The patient underwent a wide local excision of the lesion. Intraoperatively, the mass appeared infiltrative and involved the dermal and subcutaneous tissue planes. Gross examination revealed a firm tumor.

Histopathology confirmed fibromatous DFSP, Grade 3. Immunohistochemistry reported the tumor to be CD34 positive and CD68, CD117, CD10, Pan CK, Desmin, SMA, and SOX10, and CD117 were all negative [Figure 2]. Deep margin and one peripheral margin are involved by the tumor. As the initial lesion was very large lesion, making re-excision of the margins difficult. The family was counseled for local radiotherapy, but they refused any further treatment. The child has not had a local recurrence in the last 6 months. Whole body positron emission tomography CT was done after 1 year of surgery which showed no abnormal metabolically active lesion in the region of scalp or visualized body surveyed.

Figure 2.

(a) Classical areas of dermatofibrosarcoma protuberans, tumor cells arranged in a monotonous storiform pattern (H and E, ×100) (b) Cells arranged in storiform pattern with presence of mitotic figures (H and E, ×400) (c) The area showing abrupt taransition to the fibrosarcomatous component (H and E, ×100) (d) Fibrosarcomatous area (H and E, ×400) (e) Immunohistochemistry (IHC): showing CD30 positivity (×400) (f) IHC: CD34 loss in sarcomatous area (×400) (g) Ki67 25%–30% (×400) (h) IHC-p53, wild type (×400)

DISCUSSION

DFSP is a locally aggressive tumor known for a high rate of local recurrence but a comparatively low risk of metastasis.[1]

Pediatric cases are rare, leading to delayed diagnosis since the lesion frequently mimics benign skin growths. Scalp involvement is particularly rare and presents surgical challenges due to the limited availability of surrounding tissue for wide excision. The tumor typically arises from the dermis and infiltrates surrounding tissues with tentacle-like projections, which explains the high recurrence rate when margins are inadequate.[3] Histologically, DFSP is characterized by spindle cells arranged in a storiform pattern, and immunohistochemical staining usually shows strong CD34 positivity.[4]

The standard treatment for DFSP remains wide local excision with clear margins.[5] Mohs micrographic surgery has been employed to reduce recurrence through margin control. Adjuvant radiotherapy may be considered in cases where negative margins are unobtainable. Long-term monitoring is important because recurrences might arise several years postsurgery.[3]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given their consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal patient identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.